diff options
Diffstat (limited to 'kernel/rcu/rcutorture.c')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 4057 |
1 files changed, 3411 insertions, 646 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index b8f7f8ce8575..07e51974b06b 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1,27 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update module-based torture test facility * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2005, 2006 * - * Authors: Paul E. McKenney <paulmck@us.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> * Josh Triplett <josh@joshtriplett.org> * - * See also: Documentation/RCU/torture.txt + * See also: Documentation/RCU/torture.rst */ + +#define pr_fmt(fmt) fmt + #include <linux/types.h> #include <linux/kernel.h> #include <linux/init.h> @@ -30,7 +20,8 @@ #include <linux/err.h> #include <linux/spinlock.h> #include <linux/smp.h> -#include <linux/rcupdate.h> +#include <linux/rcupdate_wait.h> +#include <linux/rcu_notifier.h> #include <linux/interrupt.h> #include <linux/sched/signal.h> #include <uapi/linux/sched/types.h> @@ -51,81 +42,153 @@ #include <asm/byteorder.h> #include <linux/torture.h> #include <linux/vmalloc.h> +#include <linux/sched/debug.h> +#include <linux/sched/sysctl.h> +#include <linux/oom.h> +#include <linux/tick.h> +#include <linux/rcupdate_trace.h> +#include <linux/nmi.h> #include "rcu.h" +MODULE_DESCRIPTION("Read-Copy Update module-based torture test facility"); MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); - - -torture_param(int, cbflood_inter_holdoff, HZ, - "Holdoff between floods (jiffies)"); -torture_param(int, cbflood_intra_holdoff, 1, - "Holdoff between bursts (jiffies)"); -torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable"); -torture_param(int, cbflood_n_per_burst, 20000, - "# callbacks per burst in flood"); -torture_param(int, fqs_duration, 0, - "Duration of fqs bursts (us), 0 to disable"); +MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); + +// Bits for ->extendables field, extendables param, and related definitions. +#define RCUTORTURE_RDR_SHIFT_1 8 // Put SRCU index in upper bits. +#define RCUTORTURE_RDR_MASK_1 (0xff << RCUTORTURE_RDR_SHIFT_1) +#define RCUTORTURE_RDR_SHIFT_2 16 // Put SRCU index in upper bits. +#define RCUTORTURE_RDR_MASK_2 (0xff << RCUTORTURE_RDR_SHIFT_2) +#define RCUTORTURE_RDR_BH 0x01 // Extend readers by disabling bh. +#define RCUTORTURE_RDR_IRQ 0x02 // ... disabling interrupts. +#define RCUTORTURE_RDR_PREEMPT 0x04 // ... disabling preemption. +#define RCUTORTURE_RDR_RBH 0x08 // ... rcu_read_lock_bh(). +#define RCUTORTURE_RDR_SCHED 0x10 // ... rcu_read_lock_sched(). +#define RCUTORTURE_RDR_RCU_1 0x20 // ... entering another RCU reader. +#define RCUTORTURE_RDR_RCU_2 0x40 // ... entering another RCU reader. +#define RCUTORTURE_RDR_UPDOWN 0x80 // ... up-read from task, down-read from timer. + // Note: Manual start, automatic end. +#define RCUTORTURE_RDR_NBITS 8 // Number of bits defined above. +#define RCUTORTURE_MAX_EXTEND \ + (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ + RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) // Intentionally omit RCUTORTURE_RDR_UPDOWN. +#define RCUTORTURE_RDR_ALLBITS \ + (RCUTORTURE_MAX_EXTEND | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2 | \ + RCUTORTURE_RDR_MASK_1 | RCUTORTURE_RDR_MASK_2) +#define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ + /* Must be power of two minus one. */ +#define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) + +torture_param(int, extendables, RCUTORTURE_MAX_EXTEND, + "Extend readers by disabling bh (1), irqs (2), or preempt (4)"); +torture_param(int, fqs_duration, 0, "Duration of fqs bursts (us), 0 to disable"); torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); +torture_param(int, fwd_progress, 1, "Number of grace-period forward progress tasks (0 to disable)"); +torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait"); +torture_param(int, fwd_progress_holdoff, 60, "Time between forward-progress tests (s)"); +torture_param(bool, fwd_progress_need_resched, 1, "Hide cond_resched() behind need_resched()"); torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); +torture_param(bool, gp_cond_exp, false, "Use conditional/async expedited GP wait primitives"); +torture_param(bool, gp_cond_full, false, "Use conditional/async full-state GP wait primitives"); +torture_param(bool, gp_cond_exp_full, false, + "Use conditional/async full-stateexpedited GP wait primitives"); +torture_param(int, gp_cond_wi, 16 * USEC_PER_SEC / HZ, + "Wait interval for normal conditional grace periods, us (default 16 jiffies)"); +torture_param(int, gp_cond_wi_exp, 128, + "Wait interval for expedited conditional grace periods, us (default 128 us)"); torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); -torture_param(bool, gp_normal, false, - "Use normal (non-expedited) GP wait primitives"); +torture_param(bool, gp_normal, false, "Use normal (non-expedited) GP wait primitives"); +torture_param(bool, gp_poll, false, "Use polling GP wait primitives"); +torture_param(bool, gp_poll_exp, false, "Use polling expedited GP wait primitives"); +torture_param(bool, gp_poll_full, false, "Use polling full-state GP wait primitives"); +torture_param(bool, gp_poll_exp_full, false, "Use polling full-state expedited GP wait primitives"); +torture_param(int, gp_poll_wi, 16 * USEC_PER_SEC / HZ, + "Wait interval for normal polled grace periods, us (default 16 jiffies)"); +torture_param(int, gp_poll_wi_exp, 128, + "Wait interval for expedited polled grace periods, us (default 128 us)"); torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); -torture_param(int, n_barrier_cbs, 0, - "# of callbacks/kthreads for barrier testing"); +torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers"); +torture_param(int, n_barrier_cbs, 0, "# of callbacks/kthreads for barrier testing"); +torture_param(int, n_up_down, 32, "# of concurrent up/down hrtimer-based RCU readers"); torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); torture_param(int, nreaders, -1, "Number of RCU reader threads"); -torture_param(int, object_debug, 0, - "Enable debug-object double call_rcu() testing"); +torture_param(int, object_debug, 0, "Enable debug-object double call_rcu() testing"); torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); -torture_param(int, onoff_interval, 0, - "Time between CPU hotplugs (s), 0=disable"); +torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable"); +torture_param(bool, gpwrap_lag, true, "Enable grace-period wrap lag testing"); +torture_param(int, gpwrap_lag_gps, 8, "Value to set for set_gpwrap_lag during an active testing period."); +torture_param(int, gpwrap_lag_cycle_mins, 30, "Total cycle duration for gpwrap lag testing (in minutes)"); +torture_param(int, gpwrap_lag_active_mins, 5, "Duration for which gpwrap lag is active within each cycle (in minutes)"); +torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disable"); +torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)"); +torture_param(int, preempt_duration, 0, "Preemption duration (ms), zero to disable"); +torture_param(int, preempt_interval, MSEC_PER_SEC, "Interval between preemptions (ms)"); +torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)"); +torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable"); +torture_param(int, reader_flavor, SRCU_READ_FLAVOR_NORMAL, "Reader flavors to use, one per bit."); torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); -torture_param(int, stall_cpu_holdoff, 10, - "Time to wait before starting stall (s)."); -torture_param(int, stat_interval, 60, - "Number of seconds between stats printk()s"); +torture_param(int, stall_cpu_holdoff, 10, "Time to wait before starting stall (s)."); +torture_param(bool, stall_no_softlockup, false, "Avoid softlockup warning during cpu stall."); +torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); +torture_param(int, stall_cpu_block, 0, "Sleep while stalling."); +torture_param(int, stall_cpu_repeat, 0, "Number of additional stalls after the first one."); +torture_param(int, stall_gp_kthread, 0, "Grace-period kthread stall duration (s)."); +torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); torture_param(int, stutter, 5, "Number of seconds to run/halt test"); torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); -torture_param(int, test_boost_duration, 4, - "Duration of each boost test, seconds."); -torture_param(int, test_boost_interval, 7, - "Interval between boost tests, seconds."); -torture_param(bool, test_no_idle_hz, true, - "Test support for tickless idle CPUs"); -torture_param(bool, verbose, true, - "Enable verbose debugging printk()s"); +torture_param(int, test_boost_duration, 4, "Duration of each boost test, seconds."); +torture_param(int, test_boost_holdoff, 0, "Holdoff time from rcutorture start, seconds."); +torture_param(int, test_boost_interval, 7, "Interval between boost tests, seconds."); +torture_param(int, test_nmis, 0, "End-test NMI tests, 0 to disable."); +torture_param(bool, test_no_idle_hz, true, "Test support for tickless idle CPUs"); +torture_param(int, test_srcu_lockdep, 0, "Test specified SRCU deadlock scenario."); +torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); static char *torture_type = "rcu"; module_param(torture_type, charp, 0444); -MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)"); +MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); +static int nrealnocbers; static int nrealreaders; -static int ncbflooders; +static int nrealfakewriters; static struct task_struct *writer_task; static struct task_struct **fakewriter_tasks; static struct task_struct **reader_tasks; +static struct task_struct *updown_task; +static struct task_struct **nocb_tasks; static struct task_struct *stats_task; -static struct task_struct **cbflood_task; static struct task_struct *fqs_task; static struct task_struct *boost_tasks[NR_CPUS]; static struct task_struct *stall_task; +static struct task_struct **fwd_prog_tasks; static struct task_struct **barrier_cbs_tasks; static struct task_struct *barrier_task; +static struct task_struct *read_exit_task; +static struct task_struct *preempt_task; #define RCU_TORTURE_PIPE_LEN 10 +// Mailbox-like structure to check RCU global memory ordering. +struct rcu_torture_reader_check { + unsigned long rtc_myloops; + int rtc_chkrdr; + unsigned long rtc_chkloops; + int rtc_ready; + struct rcu_torture_reader_check *rtc_assigner; +} ____cacheline_internodealigned_in_smp; + +// Update-side data structure used to check RCU readers. struct rcu_torture { struct rcu_head rtort_rcu; int rtort_pipe_count; struct list_head rtort_free; int rtort_mbtest; + struct rcu_torture_reader_check *rtort_chkp; }; static LIST_HEAD(rcu_torture_freelist); @@ -136,21 +199,27 @@ static DEFINE_SPINLOCK(rcu_torture_lock); static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; +static struct rcu_torture_reader_check *rcu_torture_reader_mbchk; static atomic_t n_rcu_torture_alloc; static atomic_t n_rcu_torture_alloc_fail; static atomic_t n_rcu_torture_free; static atomic_t n_rcu_torture_mberror; +static atomic_t n_rcu_torture_mbchk_fail; +static atomic_t n_rcu_torture_mbchk_tries; static atomic_t n_rcu_torture_error; static long n_rcu_torture_barrier_error; static long n_rcu_torture_boost_ktrerror; -static long n_rcu_torture_boost_rterror; static long n_rcu_torture_boost_failure; static long n_rcu_torture_boosts; -static long n_rcu_torture_timers; +static atomic_long_t n_rcu_torture_timers; static long n_barrier_attempts; -static long n_barrier_successes; -static atomic_long_t n_cbfloods; +static long n_barrier_successes; /* did rcu_barrier test succeed? */ +static unsigned long n_read_exits; static struct list_head rcu_torture_removed; +static unsigned long shutdown_jiffies; +static unsigned long start_gp_seq; +static atomic_long_t n_nocb_offload; +static atomic_long_t n_nocb_deoffload; static int rcu_torture_writer_state; #define RTWS_FIXED_DELAY 0 @@ -159,10 +228,24 @@ static int rcu_torture_writer_state; #define RTWS_DEF_FREE 3 #define RTWS_EXP_SYNC 4 #define RTWS_COND_GET 5 -#define RTWS_COND_SYNC 6 -#define RTWS_SYNC 7 -#define RTWS_STUTTER 8 -#define RTWS_STOPPING 9 +#define RTWS_COND_GET_FULL 6 +#define RTWS_COND_GET_EXP 7 +#define RTWS_COND_GET_EXP_FULL 8 +#define RTWS_COND_SYNC 9 +#define RTWS_COND_SYNC_FULL 10 +#define RTWS_COND_SYNC_EXP 11 +#define RTWS_COND_SYNC_EXP_FULL 12 +#define RTWS_POLL_GET 13 +#define RTWS_POLL_GET_FULL 14 +#define RTWS_POLL_GET_EXP 15 +#define RTWS_POLL_GET_EXP_FULL 16 +#define RTWS_POLL_WAIT 17 +#define RTWS_POLL_WAIT_FULL 18 +#define RTWS_POLL_WAIT_EXP 19 +#define RTWS_POLL_WAIT_EXP_FULL 20 +#define RTWS_SYNC 21 +#define RTWS_STUTTER 22 +#define RTWS_STOPPING 23 static const char * const rcu_torture_writer_state_names[] = { "RTWS_FIXED_DELAY", "RTWS_DELAY", @@ -170,12 +253,44 @@ static const char * const rcu_torture_writer_state_names[] = { "RTWS_DEF_FREE", "RTWS_EXP_SYNC", "RTWS_COND_GET", + "RTWS_COND_GET_FULL", + "RTWS_COND_GET_EXP", + "RTWS_COND_GET_EXP_FULL", "RTWS_COND_SYNC", + "RTWS_COND_SYNC_FULL", + "RTWS_COND_SYNC_EXP", + "RTWS_COND_SYNC_EXP_FULL", + "RTWS_POLL_GET", + "RTWS_POLL_GET_FULL", + "RTWS_POLL_GET_EXP", + "RTWS_POLL_GET_EXP_FULL", + "RTWS_POLL_WAIT", + "RTWS_POLL_WAIT_FULL", + "RTWS_POLL_WAIT_EXP", + "RTWS_POLL_WAIT_EXP_FULL", "RTWS_SYNC", "RTWS_STUTTER", "RTWS_STOPPING", }; +/* Record reader segment types and duration for first failing read. */ +struct rt_read_seg { + int rt_readstate; + unsigned long rt_delay_jiffies; + unsigned long rt_delay_ms; + unsigned long rt_delay_us; + bool rt_preempted; + int rt_cpu; + int rt_end_cpu; + unsigned long long rt_gp_seq; + unsigned long long rt_gp_seq_end; + u64 rt_ts; +}; +static int err_segs_recorded; +static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; +static int rt_read_nsegs; +static int rt_read_preempted; + static const char *rcu_torture_writer_state_getname(void) { unsigned int i = READ_ONCE(rcu_torture_writer_state); @@ -185,21 +300,12 @@ static const char *rcu_torture_writer_state_getname(void) return rcu_torture_writer_state_names[i]; } -static int torture_runnable = IS_ENABLED(MODULE); -module_param(torture_runnable, int, 0444); -MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot"); - -#if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) -#define rcu_can_boost() 1 -#else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ -#define rcu_can_boost() 0 -#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ - #ifdef CONFIG_RCU_TRACE static u64 notrace rcu_trace_clock_local(void) { u64 ts = trace_clock_local(); - unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC); + + (void)do_div(ts, NSEC_PER_USEC); return ts; } #else /* #ifdef CONFIG_RCU_TRACE */ @@ -209,6 +315,15 @@ static u64 notrace rcu_trace_clock_local(void) } #endif /* #else #ifdef CONFIG_RCU_TRACE */ +/* + * Stop aggressive CPU-hog tests a bit before the end of the test in order + * to avoid interfering with test shutdown. + */ +static bool shutdown_time_arrived(void) +{ + return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ); +} + static unsigned long boost_starttime; /* jiffies of next boost test start. */ static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ /* and boost task create/destroy. */ @@ -218,6 +333,8 @@ static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); +static atomic_t rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */ + /* * Allocate an element from the rcu_tortures pool. */ @@ -260,21 +377,64 @@ struct rcu_torture_ops { void (*init)(void); void (*cleanup)(void); int (*readlock)(void); - void (*read_delay)(struct torture_random_state *rrsp); + void (*read_delay)(struct torture_random_state *rrsp, + struct rt_read_seg *rtrsp); void (*readunlock)(int idx); - unsigned long (*started)(void); - unsigned long (*completed)(void); + int (*readlock_held)(void); // lockdep. + int (*readlock_nesting)(void); // actual nesting, if available, -1 if not. + int (*down_read)(void); + void (*up_read)(int idx); + unsigned long (*get_gp_seq)(void); + unsigned long (*gp_diff)(unsigned long new, unsigned long old); void (*deferred_free)(struct rcu_torture *p); void (*sync)(void); void (*exp_sync)(void); - unsigned long (*get_state)(void); + void (*exp_current)(void); + unsigned long (*get_gp_state_exp)(void); + unsigned long (*start_gp_poll_exp)(void); + void (*start_gp_poll_exp_full)(struct rcu_gp_oldstate *rgosp); + bool (*poll_gp_state_exp)(unsigned long oldstate); + void (*cond_sync_exp)(unsigned long oldstate); + void (*cond_sync_exp_full)(struct rcu_gp_oldstate *rgosp); + unsigned long (*get_comp_state)(void); + void (*get_comp_state_full)(struct rcu_gp_oldstate *rgosp); + bool (*same_gp_state)(unsigned long oldstate1, unsigned long oldstate2); + bool (*same_gp_state_full)(struct rcu_gp_oldstate *rgosp1, struct rcu_gp_oldstate *rgosp2); + unsigned long (*get_gp_state)(void); + void (*get_gp_state_full)(struct rcu_gp_oldstate *rgosp); + unsigned long (*start_gp_poll)(void); + void (*start_gp_poll_full)(struct rcu_gp_oldstate *rgosp); + bool (*poll_gp_state)(unsigned long oldstate); + bool (*poll_gp_state_full)(struct rcu_gp_oldstate *rgosp); + bool (*poll_need_2gp)(bool poll, bool poll_full); void (*cond_sync)(unsigned long oldstate); + void (*cond_sync_full)(struct rcu_gp_oldstate *rgosp); + int poll_active; + int poll_active_full; call_rcu_func_t call; void (*cb_barrier)(void); void (*fqs)(void); void (*stats)(void); + void (*gp_kthread_dbg)(void); + bool (*check_boost_failed)(unsigned long gp_state, int *cpup); + int (*stall_dur)(void); + void (*get_gp_data)(int *flags, unsigned long *gp_seq); + void (*gp_slow_register)(atomic_t *rgssp); + void (*gp_slow_unregister)(atomic_t *rgssp); + bool (*reader_blocked)(void); + unsigned long long (*gather_gp_seqs)(void); + void (*format_gp_seqs)(unsigned long long seqs, char *cp, size_t len); + void (*set_gpwrap_lag)(unsigned long lag); + int (*get_gpwrap_count)(int cpu); + long cbflood_max; int irq_capable; int can_boost; + int extendables; + int slow_gps; + int no_pi_lock; + int debug_objects; + int start_poll_irqsoff; + int have_up_down; const char *name; }; @@ -284,46 +444,65 @@ static struct rcu_torture_ops *cur_ops; * Definitions for rcu torture testing. */ -static int rcu_torture_read_lock(void) __acquires(RCU) +static int torture_readlock_not_held(void) +{ + return rcu_read_lock_bh_held() || rcu_read_lock_sched_held(); +} + +static int rcu_torture_read_lock(void) { rcu_read_lock(); return 0; } -static void rcu_read_delay(struct torture_random_state *rrsp) +static void +rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) { unsigned long started; unsigned long completed; const unsigned long shortdelay_us = 200; - const unsigned long longdelay_ms = 50; + unsigned long longdelay_ms = 300; unsigned long long ts; /* We want a short delay sometimes to make a reader delay the grace * period, and we want a long delay occasionally to trigger * force_quiescent_state. */ - if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { - started = cur_ops->completed(); + if (!atomic_read(&rcu_fwd_cb_nodelay) && + !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { + started = cur_ops->get_gp_seq(); ts = rcu_trace_clock_local(); + if ((preempt_count() & HARDIRQ_MASK) || softirq_count()) + longdelay_ms = 5; /* Avoid triggering BH limits. */ mdelay(longdelay_ms); - completed = cur_ops->completed(); + rtrsp->rt_delay_ms = longdelay_ms; + completed = cur_ops->get_gp_seq(); do_trace_rcu_torture_read(cur_ops->name, NULL, ts, started, completed); } - if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) + if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { udelay(shortdelay_us); -#ifdef CONFIG_PREEMPT + rtrsp->rt_delay_us = shortdelay_us; + } if (!preempt_count() && - !(torture_random(rrsp) % (nrealreaders * 20000))) - preempt_schedule(); /* No QS if preempt_disable() in effect */ -#endif + !(torture_random(rrsp) % (nrealreaders * 500))) + torture_preempt_schedule(); /* QS only if preemptible. */ } -static void rcu_torture_read_unlock(int idx) __releases(RCU) +static void rcu_torture_read_unlock(int idx) { rcu_read_unlock(); } +static int rcu_torture_readlock_nesting(void) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RCU)) + return rcu_preempt_depth(); + if (IS_ENABLED(CONFIG_PREEMPT_COUNT)) + return (preempt_count() & PREEMPT_MASK); + return -1; +} + /* * Update callback in the pipe. This should be invoked after a grace period. */ @@ -331,12 +510,19 @@ static bool rcu_torture_pipe_update_one(struct rcu_torture *rp) { int i; + struct rcu_torture_reader_check *rtrcp = READ_ONCE(rp->rtort_chkp); + if (rtrcp) { + WRITE_ONCE(rp->rtort_chkp, NULL); + smp_store_release(&rtrcp->rtc_ready, 1); // Pair with smp_load_acquire(). + } i = rp->rtort_pipe_count; if (i > RCU_TORTURE_PIPE_LEN) i = RCU_TORTURE_PIPE_LEN; atomic_inc(&rcu_torture_wcount[i]); - if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { + WRITE_ONCE(rp->rtort_pipe_count, i + 1); + ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count); + if (i + 1 >= RCU_TORTURE_PIPE_LEN) { rp->rtort_mbtest = 0; return true; } @@ -386,7 +572,7 @@ static unsigned long rcu_no_completed(void) static void rcu_torture_deferred_free(struct rcu_torture *p) { - call_rcu(&p->rtort_rcu, rcu_torture_cb); + call_rcu_hurry(&p->rtort_rcu, rcu_torture_cb); } static void rcu_sync_torture_init(void) @@ -394,65 +580,67 @@ static void rcu_sync_torture_init(void) INIT_LIST_HEAD(&rcu_torture_removed); } -static struct rcu_torture_ops rcu_ops = { - .ttype = RCU_FLAVOR, - .init = rcu_sync_torture_init, - .readlock = rcu_torture_read_lock, - .read_delay = rcu_read_delay, - .readunlock = rcu_torture_read_unlock, - .started = rcu_batches_started, - .completed = rcu_batches_completed, - .deferred_free = rcu_torture_deferred_free, - .sync = synchronize_rcu, - .exp_sync = synchronize_rcu_expedited, - .get_state = get_state_synchronize_rcu, - .cond_sync = cond_synchronize_rcu, - .call = call_rcu, - .cb_barrier = rcu_barrier, - .fqs = rcu_force_quiescent_state, - .stats = NULL, - .irq_capable = 1, - .can_boost = rcu_can_boost(), - .name = "rcu" -}; - -/* - * Definitions for rcu_bh torture testing. - */ - -static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) -{ - rcu_read_lock_bh(); - return 0; -} - -static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) +static bool rcu_poll_need_2gp(bool poll, bool poll_full) { - rcu_read_unlock_bh(); + return poll; } -static void rcu_bh_torture_deferred_free(struct rcu_torture *p) -{ - call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); -} - -static struct rcu_torture_ops rcu_bh_ops = { - .ttype = RCU_BH_FLAVOR, - .init = rcu_sync_torture_init, - .readlock = rcu_bh_torture_read_lock, - .read_delay = rcu_read_delay, /* just reuse rcu's version. */ - .readunlock = rcu_bh_torture_read_unlock, - .started = rcu_batches_started_bh, - .completed = rcu_batches_completed_bh, - .deferred_free = rcu_bh_torture_deferred_free, - .sync = synchronize_rcu_bh, - .exp_sync = synchronize_rcu_bh_expedited, - .call = call_rcu_bh, - .cb_barrier = rcu_barrier_bh, - .fqs = rcu_bh_force_quiescent_state, - .stats = NULL, - .irq_capable = 1, - .name = "rcu_bh" +static struct rcu_torture_ops rcu_ops = { + .ttype = RCU_FLAVOR, + .init = rcu_sync_torture_init, + .readlock = rcu_torture_read_lock, + .read_delay = rcu_read_delay, + .readunlock = rcu_torture_read_unlock, + .readlock_held = torture_readlock_not_held, + .readlock_nesting = rcu_torture_readlock_nesting, + .get_gp_seq = rcu_get_gp_seq, + .gp_diff = rcu_seq_diff, + .deferred_free = rcu_torture_deferred_free, + .sync = synchronize_rcu, + .exp_sync = synchronize_rcu_expedited, + .same_gp_state = same_state_synchronize_rcu, + .same_gp_state_full = same_state_synchronize_rcu_full, + .get_comp_state = get_completed_synchronize_rcu, + .get_comp_state_full = get_completed_synchronize_rcu_full, + .get_gp_state = get_state_synchronize_rcu, + .get_gp_state_full = get_state_synchronize_rcu_full, + .start_gp_poll = start_poll_synchronize_rcu, + .start_gp_poll_full = start_poll_synchronize_rcu_full, + .poll_gp_state = poll_state_synchronize_rcu, + .poll_gp_state_full = poll_state_synchronize_rcu_full, + .poll_need_2gp = rcu_poll_need_2gp, + .cond_sync = cond_synchronize_rcu, + .cond_sync_full = cond_synchronize_rcu_full, + .poll_active = NUM_ACTIVE_RCU_POLL_OLDSTATE, + .poll_active_full = NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE, + .get_gp_state_exp = get_state_synchronize_rcu, + .start_gp_poll_exp = start_poll_synchronize_rcu_expedited, + .start_gp_poll_exp_full = start_poll_synchronize_rcu_expedited_full, + .poll_gp_state_exp = poll_state_synchronize_rcu, + .cond_sync_exp = cond_synchronize_rcu_expedited, + .cond_sync_exp_full = cond_synchronize_rcu_expedited_full, + .call = call_rcu_hurry, + .cb_barrier = rcu_barrier, + .fqs = rcu_force_quiescent_state, + .gp_kthread_dbg = show_rcu_gp_kthreads, + .check_boost_failed = rcu_check_boost_fail, + .stall_dur = rcu_jiffies_till_stall_check, + .get_gp_data = rcutorture_get_gp_data, + .gp_slow_register = rcu_gp_slow_register, + .gp_slow_unregister = rcu_gp_slow_unregister, + .reader_blocked = IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU) + ? has_rcu_reader_blocked + : NULL, + .gather_gp_seqs = rcutorture_gather_gp_seqs, + .format_gp_seqs = rcutorture_format_gp_seqs, + .set_gpwrap_lag = rcu_set_gpwrap_lag, + .get_gpwrap_count = rcu_get_gpwrap_count, + .irq_capable = 1, + .can_boost = IS_ENABLED(CONFIG_RCU_BOOST), + .extendables = RCUTORTURE_MAX_EXTEND, + .debug_objects = 1, + .start_poll_irqsoff = 1, + .name = "rcu" }; /* @@ -486,17 +674,17 @@ static struct rcu_torture_ops rcu_busted_ops = { .readlock = rcu_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = rcu_torture_read_unlock, - .started = rcu_no_completed, - .completed = rcu_no_completed, + .readlock_held = torture_readlock_not_held, + .get_gp_seq = rcu_no_completed, .deferred_free = rcu_busted_torture_deferred_free, .sync = synchronize_rcu_busted, .exp_sync = synchronize_rcu_busted, .call = call_rcu_busted, - .cb_barrier = NULL, - .fqs = NULL, - .stats = NULL, + .gather_gp_seqs = rcutorture_gather_gp_seqs, + .format_gp_seqs = rcutorture_format_gp_seqs, .irq_capable = 1, - .name = "rcu_busted" + .extendables = RCUTORTURE_MAX_EXTEND, + .name = "busted" }; /* @@ -504,15 +692,69 @@ static struct rcu_torture_ops rcu_busted_ops = { */ DEFINE_STATIC_SRCU(srcu_ctl); +DEFINE_STATIC_SRCU_FAST(srcu_ctlf); +DEFINE_STATIC_SRCU_FAST_UPDOWN(srcu_ctlfud); static struct srcu_struct srcu_ctld; static struct srcu_struct *srcu_ctlp = &srcu_ctl; +static struct rcu_torture_ops srcud_ops; + +static void srcu_torture_init(void) +{ + rcu_sync_torture_init(); + if (!reader_flavor || (reader_flavor & SRCU_READ_FLAVOR_NORMAL)) + VERBOSE_TOROUT_STRING("srcu_torture_init normal SRCU"); + if (reader_flavor & SRCU_READ_FLAVOR_NMI) + VERBOSE_TOROUT_STRING("srcu_torture_init NMI-safe SRCU"); + if (reader_flavor & SRCU_READ_FLAVOR_FAST) { + srcu_ctlp = &srcu_ctlf; + VERBOSE_TOROUT_STRING("srcu_torture_init fast SRCU"); + } + if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { + srcu_ctlp = &srcu_ctlfud; + VERBOSE_TOROUT_STRING("srcu_torture_init fast-up/down SRCU"); + } +} + +static void srcu_get_gp_data(int *flags, unsigned long *gp_seq) +{ + srcutorture_get_gp_data(srcu_ctlp, flags, gp_seq); +} -static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) +static int srcu_torture_read_lock(void) { - return srcu_read_lock(srcu_ctlp); + int idx; + struct srcu_ctr __percpu *scp; + int ret = 0; + + WARN_ON_ONCE(reader_flavor & ~SRCU_READ_FLAVOR_ALL); + + if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) { + idx = srcu_read_lock(srcu_ctlp); + WARN_ON_ONCE(idx & ~0x1); + ret += idx; + } + if (reader_flavor & SRCU_READ_FLAVOR_NMI) { + idx = srcu_read_lock_nmisafe(srcu_ctlp); + WARN_ON_ONCE(idx & ~0x1); + ret += idx << 1; + } + if (reader_flavor & SRCU_READ_FLAVOR_FAST) { + scp = srcu_read_lock_fast(srcu_ctlp); + idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); + WARN_ON_ONCE(idx & ~0x1); + ret += idx << 2; + } + if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { + scp = srcu_read_lock_fast_updown(srcu_ctlp); + idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); + WARN_ON_ONCE(idx & ~0x1); + ret += idx << 3; + } + return ret; } -static void srcu_read_delay(struct torture_random_state *rrsp) +static void +srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) { long delay; const long uspertick = 1000000 / HZ; @@ -522,15 +764,75 @@ static void srcu_read_delay(struct torture_random_state *rrsp) delay = torture_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); - if (!delay) + if (!delay && in_task()) { schedule_timeout_interruptible(longdelay); - else - rcu_read_delay(rrsp); + rtrsp->rt_delay_jiffies = longdelay; + } else { + rcu_read_delay(rrsp, rtrsp); + } +} + +static void srcu_torture_read_unlock(int idx) +{ + WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1))); + if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) + srcu_read_unlock_fast_updown(srcu_ctlp, + __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x8) >> 3)); + if (reader_flavor & SRCU_READ_FLAVOR_FAST) + srcu_read_unlock_fast(srcu_ctlp, __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x4) >> 2)); + if (reader_flavor & SRCU_READ_FLAVOR_NMI) + srcu_read_unlock_nmisafe(srcu_ctlp, (idx & 0x2) >> 1); + if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) + srcu_read_unlock(srcu_ctlp, idx & 0x1); +} + +static int torture_srcu_read_lock_held(void) +{ + return srcu_read_lock_held(srcu_ctlp); +} + +static bool srcu_torture_have_up_down(void) +{ + int rf = reader_flavor; + + if (!rf) + rf = SRCU_READ_FLAVOR_NORMAL; + return !!(cur_ops->have_up_down & rf); +} + +static int srcu_torture_down_read(void) +{ + int idx; + struct srcu_ctr __percpu *scp; + + WARN_ON_ONCE(reader_flavor & ~SRCU_READ_FLAVOR_ALL); + WARN_ON_ONCE(reader_flavor & (reader_flavor - 1)); + + if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || !(reader_flavor & SRCU_READ_FLAVOR_ALL)) { + idx = srcu_down_read(srcu_ctlp); + WARN_ON_ONCE(idx & ~0x1); + return idx; + } + if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { + scp = srcu_down_read_fast(srcu_ctlp); + idx = __srcu_ptr_to_ctr(srcu_ctlp, scp); + WARN_ON_ONCE(idx & ~0x1); + return idx << 3; + } + WARN_ON_ONCE(1); + return 0; } -static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) +static void srcu_torture_up_read(int idx) { - srcu_read_unlock(srcu_ctlp, idx); + WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1))); + if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) + srcu_up_read_fast(srcu_ctlp, __srcu_ctr_to_ptr(srcu_ctlp, (idx & 0x8) >> 3)); + else if ((reader_flavor & SRCU_READ_FLAVOR_NORMAL) || + !(reader_flavor & SRCU_READ_FLAVOR_ALL)) + srcu_up_read(srcu_ctlp, idx & 0x1); + else + WARN_ON_ONCE(1); } static unsigned long srcu_torture_completed(void) @@ -548,6 +850,21 @@ static void srcu_torture_synchronize(void) synchronize_srcu(srcu_ctlp); } +static unsigned long srcu_torture_get_gp_state(void) +{ + return get_state_synchronize_srcu(srcu_ctlp); +} + +static unsigned long srcu_torture_start_gp_poll(void) +{ + return start_poll_synchronize_srcu(srcu_ctlp); +} + +static bool srcu_torture_poll_gp_state(unsigned long oldstate) +{ + return poll_state_synchronize_srcu(srcu_ctlp, oldstate); +} + static void srcu_torture_call(struct rcu_head *head, rcu_callback_t func) { @@ -561,44 +878,7 @@ static void srcu_torture_barrier(void) static void srcu_torture_stats(void) { - int __maybe_unused cpu; - int idx; - -#ifdef CONFIG_TREE_SRCU - idx = srcu_ctlp->srcu_idx & 0x1; - pr_alert("%s%s Tree SRCU per-CPU(idx=%d):", - torture_type, TORTURE_FLAG, idx); - for_each_possible_cpu(cpu) { - unsigned long l0, l1; - unsigned long u0, u1; - long c0, c1; - struct srcu_data *counts; - - counts = per_cpu_ptr(srcu_ctlp->sda, cpu); - u0 = counts->srcu_unlock_count[!idx]; - u1 = counts->srcu_unlock_count[idx]; - - /* - * Make sure that a lock is always counted if the corresponding - * unlock is counted. - */ - smp_rmb(); - - l0 = counts->srcu_lock_count[!idx]; - l1 = counts->srcu_lock_count[idx]; - - c0 = l0 - u0; - c1 = l1 - u1; - pr_cont(" %d(%ld,%ld)", cpu, c0, c1); - } - pr_cont("\n"); -#elif defined(CONFIG_TINY_SRCU) - idx = READ_ONCE(srcu_ctlp->srcu_idx) & 0x1; - pr_alert("%s%s Tiny SRCU per-CPU(idx=%d): (%hd,%hd)\n", - torture_type, TORTURE_FLAG, idx, - READ_ONCE(srcu_ctlp->srcu_lock_nesting[!idx]), - READ_ONCE(srcu_ctlp->srcu_lock_nesting[idx])); -#endif + srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); } static void srcu_torture_synchronize_expedited(void) @@ -606,27 +886,63 @@ static void srcu_torture_synchronize_expedited(void) synchronize_srcu_expedited(srcu_ctlp); } +static void srcu_torture_expedite_current(void) +{ + srcu_expedite_current(srcu_ctlp); +} + static struct rcu_torture_ops srcu_ops = { .ttype = SRCU_FLAVOR, - .init = rcu_sync_torture_init, + .init = srcu_torture_init, .readlock = srcu_torture_read_lock, .read_delay = srcu_read_delay, .readunlock = srcu_torture_read_unlock, - .started = NULL, - .completed = srcu_torture_completed, + .down_read = srcu_torture_down_read, + .up_read = srcu_torture_up_read, + .readlock_held = torture_srcu_read_lock_held, + .get_gp_seq = srcu_torture_completed, + .gp_diff = rcu_seq_diff, .deferred_free = srcu_torture_deferred_free, .sync = srcu_torture_synchronize, .exp_sync = srcu_torture_synchronize_expedited, + .exp_current = srcu_torture_expedite_current, + .same_gp_state = same_state_synchronize_srcu, + .get_comp_state = get_completed_synchronize_srcu, + .get_gp_state = srcu_torture_get_gp_state, + .start_gp_poll = srcu_torture_start_gp_poll, + .poll_gp_state = srcu_torture_poll_gp_state, + .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, .call = srcu_torture_call, .cb_barrier = srcu_torture_barrier, .stats = srcu_torture_stats, + .get_gp_data = srcu_get_gp_data, + .cbflood_max = 50000, + .irq_capable = 1, + .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), + .debug_objects = 1, + .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) + ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, .name = "srcu" }; -static void srcu_torture_init(void) +static void srcud_torture_init(void) { rcu_sync_torture_init(); - WARN_ON(init_srcu_struct(&srcu_ctld)); + if (!reader_flavor || (reader_flavor & SRCU_READ_FLAVOR_NORMAL)) { + WARN_ON(init_srcu_struct(&srcu_ctld)); + VERBOSE_TOROUT_STRING("srcud_torture_init normal SRCU"); + } else if (reader_flavor & SRCU_READ_FLAVOR_NMI) { + WARN_ON(init_srcu_struct(&srcu_ctld)); + VERBOSE_TOROUT_STRING("srcud_torture_init NMI-safe SRCU"); + } else if (reader_flavor & SRCU_READ_FLAVOR_FAST) { + WARN_ON(init_srcu_struct_fast(&srcu_ctld)); + VERBOSE_TOROUT_STRING("srcud_torture_init fast SRCU"); + } else if (reader_flavor & SRCU_READ_FLAVOR_FAST_UPDOWN) { + WARN_ON(init_srcu_struct_fast_updown(&srcu_ctld)); + VERBOSE_TOROUT_STRING("srcud_torture_init fast-up/down SRCU"); + } else { + WARN_ON(init_srcu_struct(&srcu_ctld)); + } srcu_ctlp = &srcu_ctld; } @@ -639,61 +955,110 @@ static void srcu_torture_cleanup(void) /* As above, but dynamically allocated. */ static struct rcu_torture_ops srcud_ops = { .ttype = SRCU_FLAVOR, - .init = srcu_torture_init, + .init = srcud_torture_init, .cleanup = srcu_torture_cleanup, .readlock = srcu_torture_read_lock, .read_delay = srcu_read_delay, .readunlock = srcu_torture_read_unlock, - .started = NULL, - .completed = srcu_torture_completed, + .readlock_held = torture_srcu_read_lock_held, + .down_read = srcu_torture_down_read, + .up_read = srcu_torture_up_read, + .get_gp_seq = srcu_torture_completed, + .gp_diff = rcu_seq_diff, .deferred_free = srcu_torture_deferred_free, .sync = srcu_torture_synchronize, .exp_sync = srcu_torture_synchronize_expedited, + .exp_current = srcu_torture_expedite_current, + .same_gp_state = same_state_synchronize_srcu, + .get_comp_state = get_completed_synchronize_srcu, + .get_gp_state = srcu_torture_get_gp_state, + .start_gp_poll = srcu_torture_start_gp_poll, + .poll_gp_state = srcu_torture_poll_gp_state, + .poll_active = NUM_ACTIVE_SRCU_POLL_OLDSTATE, .call = srcu_torture_call, .cb_barrier = srcu_torture_barrier, .stats = srcu_torture_stats, + .get_gp_data = srcu_get_gp_data, + .cbflood_max = 50000, + .irq_capable = 1, + .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), + .debug_objects = 1, + .have_up_down = IS_ENABLED(CONFIG_TINY_SRCU) + ? 0 : SRCU_READ_FLAVOR_NORMAL | SRCU_READ_FLAVOR_FAST_UPDOWN, .name = "srcud" }; +/* As above, but broken due to inappropriate reader extension. */ +static struct rcu_torture_ops busted_srcud_ops = { + .ttype = SRCU_FLAVOR, + .init = srcu_torture_init, + .cleanup = srcu_torture_cleanup, + .readlock = srcu_torture_read_lock, + .read_delay = rcu_read_delay, + .readunlock = srcu_torture_read_unlock, + .readlock_held = torture_srcu_read_lock_held, + .get_gp_seq = srcu_torture_completed, + .deferred_free = srcu_torture_deferred_free, + .sync = srcu_torture_synchronize, + .exp_sync = srcu_torture_synchronize_expedited, + .call = srcu_torture_call, + .cb_barrier = srcu_torture_barrier, + .stats = srcu_torture_stats, + .irq_capable = 1, + .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU), + .extendables = RCUTORTURE_MAX_EXTEND, + .name = "busted_srcud" +}; + /* - * Definitions for sched torture testing. + * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. + * This implementation does not work well with CPU hotplug nor + * with rcutorture's shuffling. */ -static int sched_torture_read_lock(void) +static void synchronize_rcu_trivial(void) { - preempt_disable(); - return 0; + int cpu; + + for_each_online_cpu(cpu) { + torture_sched_setaffinity(current->pid, cpumask_of(cpu), true); + WARN_ON_ONCE(raw_smp_processor_id() != cpu); + } } -static void sched_torture_read_unlock(int idx) +static void rcu_sync_torture_init_trivial(void) { - preempt_enable(); + rcu_sync_torture_init(); + // if (onoff_interval || shuffle_interval) { + if (WARN_ONCE(onoff_interval || shuffle_interval, "%s: Non-zero onoff_interval (%d) or shuffle_interval (%d) breaks trivial RCU, resetting to zero", __func__, onoff_interval, shuffle_interval)) { + onoff_interval = 0; + shuffle_interval = 0; + } } -static void rcu_sched_torture_deferred_free(struct rcu_torture *p) +static int rcu_torture_read_lock_trivial(void) { - call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); + preempt_disable(); + return 0; } -static struct rcu_torture_ops sched_ops = { - .ttype = RCU_SCHED_FLAVOR, - .init = rcu_sync_torture_init, - .readlock = sched_torture_read_lock, +static void rcu_torture_read_unlock_trivial(int idx) +{ + preempt_enable(); +} + +static struct rcu_torture_ops trivial_ops = { + .ttype = RCU_TRIVIAL_FLAVOR, + .init = rcu_sync_torture_init_trivial, + .readlock = rcu_torture_read_lock_trivial, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ - .readunlock = sched_torture_read_unlock, - .started = rcu_batches_started_sched, - .completed = rcu_batches_completed_sched, - .deferred_free = rcu_sched_torture_deferred_free, - .sync = synchronize_sched, - .exp_sync = synchronize_sched_expedited, - .get_state = get_state_synchronize_sched, - .cond_sync = cond_synchronize_sched, - .call = call_rcu_sched, - .cb_barrier = rcu_barrier_sched, - .fqs = rcu_sched_force_quiescent_state, - .stats = NULL, + .readunlock = rcu_torture_read_unlock_trivial, + .readlock_held = torture_readlock_not_held, + .get_gp_seq = rcu_no_completed, + .sync = synchronize_rcu_trivial, + .exp_sync = synchronize_rcu_trivial, .irq_capable = 1, - .name = "sched" + .name = "trivial" }; #ifdef CONFIG_TASKS_RCU @@ -716,114 +1081,281 @@ static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); } +static void synchronize_rcu_mult_test(void) +{ + synchronize_rcu_mult(call_rcu_tasks, call_rcu_hurry); +} + static struct rcu_torture_ops tasks_ops = { .ttype = RCU_TASKS_FLAVOR, .init = rcu_sync_torture_init, .readlock = tasks_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = tasks_torture_read_unlock, - .started = rcu_no_completed, - .completed = rcu_no_completed, + .get_gp_seq = rcu_no_completed, .deferred_free = rcu_tasks_torture_deferred_free, .sync = synchronize_rcu_tasks, - .exp_sync = synchronize_rcu_tasks, + .exp_sync = synchronize_rcu_mult_test, .call = call_rcu_tasks, .cb_barrier = rcu_barrier_tasks, - .fqs = NULL, - .stats = NULL, + .gp_kthread_dbg = show_rcu_tasks_classic_gp_kthread, + .get_gp_data = rcu_tasks_get_gp_data, .irq_capable = 1, + .slow_gps = 1, .name = "tasks" }; -#define RCUTORTURE_TASKS_OPS &tasks_ops, +#define TASKS_OPS &tasks_ops, + +#else // #ifdef CONFIG_TASKS_RCU + +#define TASKS_OPS + +#endif // #else #ifdef CONFIG_TASKS_RCU + + +#ifdef CONFIG_TASKS_RUDE_RCU + +/* + * Definitions for rude RCU-tasks torture testing. + */ + +static struct rcu_torture_ops tasks_rude_ops = { + .ttype = RCU_TASKS_RUDE_FLAVOR, + .init = rcu_sync_torture_init, + .readlock = rcu_torture_read_lock_trivial, + .read_delay = rcu_read_delay, /* just reuse rcu's version. */ + .readunlock = rcu_torture_read_unlock_trivial, + .get_gp_seq = rcu_no_completed, + .sync = synchronize_rcu_tasks_rude, + .exp_sync = synchronize_rcu_tasks_rude, + .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread, + .get_gp_data = rcu_tasks_rude_get_gp_data, + .cbflood_max = 50000, + .irq_capable = 1, + .name = "tasks-rude" +}; + +#define TASKS_RUDE_OPS &tasks_rude_ops, + +#else // #ifdef CONFIG_TASKS_RUDE_RCU + +#define TASKS_RUDE_OPS + +#endif // #else #ifdef CONFIG_TASKS_RUDE_RCU + -static bool __maybe_unused torturing_tasks(void) +#ifdef CONFIG_TASKS_TRACE_RCU + +/* + * Definitions for tracing RCU-tasks torture testing. + */ + +static int tasks_tracing_torture_read_lock(void) { - return cur_ops == &tasks_ops; + rcu_read_lock_trace(); + return 0; } -#else /* #ifdef CONFIG_TASKS_RCU */ - -#define RCUTORTURE_TASKS_OPS +static void tasks_tracing_torture_read_unlock(int idx) +{ + rcu_read_unlock_trace(); +} -static bool __maybe_unused torturing_tasks(void) +static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p) { - return false; + call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb); } -#endif /* #else #ifdef CONFIG_TASKS_RCU */ +static struct rcu_torture_ops tasks_tracing_ops = { + .ttype = RCU_TASKS_TRACING_FLAVOR, + .init = rcu_sync_torture_init, + .readlock = tasks_tracing_torture_read_lock, + .read_delay = srcu_read_delay, /* just reuse srcu's version. */ + .readunlock = tasks_tracing_torture_read_unlock, + .readlock_held = rcu_read_lock_trace_held, + .get_gp_seq = rcu_no_completed, + .deferred_free = rcu_tasks_tracing_torture_deferred_free, + .sync = synchronize_rcu_tasks_trace, + .exp_sync = synchronize_rcu_tasks_trace, + .call = call_rcu_tasks_trace, + .cb_barrier = rcu_barrier_tasks_trace, + .gp_kthread_dbg = show_rcu_tasks_trace_gp_kthread, + .get_gp_data = rcu_tasks_trace_get_gp_data, + .cbflood_max = 50000, + .irq_capable = 1, + .slow_gps = 1, + .name = "tasks-tracing" +}; + +#define TASKS_TRACING_OPS &tasks_tracing_ops, + +#else // #ifdef CONFIG_TASKS_TRACE_RCU + +#define TASKS_TRACING_OPS + +#endif // #else #ifdef CONFIG_TASKS_TRACE_RCU + + +static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) +{ + if (!cur_ops->gp_diff) + return new - old; + return cur_ops->gp_diff(new, old); +} /* * RCU torture priority-boost testing. Runs one real-time thread per - * CPU for moderate bursts, repeatedly registering RCU callbacks and - * spinning waiting for them to be invoked. If a given callback takes - * too long to be invoked, we assume that priority inversion has occurred. + * CPU for moderate bursts, repeatedly starting grace periods and waiting + * for them to complete. If a given grace period takes too long, we assume + * that priority inversion has occurred. */ -struct rcu_boost_inflight { - struct rcu_head rcu; - int inflight; -}; +static int old_rt_runtime = -1; -static void rcu_torture_boost_cb(struct rcu_head *head) +static void rcu_torture_disable_rt_throttle(void) { - struct rcu_boost_inflight *rbip = - container_of(head, struct rcu_boost_inflight, rcu); + /* + * Disable RT throttling so that rcutorture's boost threads don't get + * throttled. Only possible if rcutorture is built-in otherwise the + * user should manually do this by setting the sched_rt_period_us and + * sched_rt_runtime sysctls. + */ + if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) + return; - /* Ensure RCU-core accesses precede clearing ->inflight */ - smp_store_release(&rbip->inflight, 0); + old_rt_runtime = sysctl_sched_rt_runtime; + sysctl_sched_rt_runtime = -1; +} + +static void rcu_torture_enable_rt_throttle(void) +{ + if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) + return; + + sysctl_sched_rt_runtime = old_rt_runtime; + old_rt_runtime = -1; +} + +static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start) +{ + int cpu; + static int dbg_done; + unsigned long end = jiffies; + bool gp_done; + unsigned long j; + static unsigned long last_persist; + unsigned long lp; + unsigned long mininterval = test_boost_duration * HZ - HZ / 2; + + if (end - *start > mininterval) { + // Recheck after checking time to avoid false positives. + smp_mb(); // Time check before grace-period check. + if (cur_ops->poll_gp_state(gp_state)) + return false; // passed, though perhaps just barely + if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) { + // At most one persisted message per boost test. + j = jiffies; + lp = READ_ONCE(last_persist); + if (time_after(j, lp + mininterval) && + cmpxchg(&last_persist, lp, j) == lp) { + if (cpu < 0) + pr_info("Boost inversion persisted: QS from all CPUs\n"); + else + pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu); + } + return false; // passed on a technicality + } + VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); + n_rcu_torture_boost_failure++; + if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) { + pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n", + current->rt_priority, gp_state, end - *start); + cur_ops->gp_kthread_dbg(); + // Recheck after print to flag grace period ending during splat. + gp_done = cur_ops->poll_gp_state(gp_state); + pr_info("Boost inversion: GP %lu %s.\n", gp_state, + gp_done ? "ended already" : "still pending"); + + } + + return true; // failed + } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) { + *start = jiffies; + } + + return false; // passed } static int rcu_torture_boost(void *arg) { - unsigned long call_rcu_time; unsigned long endtime; + unsigned long gp_state; + unsigned long gp_state_time; unsigned long oldstarttime; - struct rcu_boost_inflight rbi = { .inflight = 0 }; - struct sched_param sp; + unsigned long booststarttime = get_torture_init_jiffies() + test_boost_holdoff * HZ; - VERBOSE_TOROUT_STRING("rcu_torture_boost started"); + if (test_boost_holdoff <= 0 || time_after(jiffies, booststarttime)) { + VERBOSE_TOROUT_STRING("rcu_torture_boost started"); + } else { + VERBOSE_TOROUT_STRING("rcu_torture_boost started holdoff period"); + while (time_before(jiffies, booststarttime)) { + schedule_timeout_idle(HZ); + if (kthread_should_stop()) + goto cleanup; + } + VERBOSE_TOROUT_STRING("rcu_torture_boost finished holdoff period"); + } /* Set real-time priority. */ - sp.sched_priority = 1; - if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { - VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); - n_rcu_torture_boost_rterror++; - } + sched_set_fifo_low(current); - init_rcu_head_on_stack(&rbi.rcu); /* Each pass through the following loop does one boost-test cycle. */ do { + bool failed = false; // Test failed already in this test interval + bool gp_initiated = false; + + if (kthread_should_stop()) + goto checkwait; + /* Wait for the next test interval. */ - oldstarttime = boost_starttime; - while (ULONG_CMP_LT(jiffies, oldstarttime)) { + oldstarttime = READ_ONCE(boost_starttime); + while (time_before(jiffies, oldstarttime)) { schedule_timeout_interruptible(oldstarttime - jiffies); - stutter_wait("rcu_torture_boost"); + if (stutter_wait("rcu_torture_boost")) + sched_set_fifo_low(current); if (torture_must_stop()) goto checkwait; } - /* Do one boost-test interval. */ + // Do one boost-test interval. endtime = oldstarttime + test_boost_duration * HZ; - call_rcu_time = jiffies; - while (ULONG_CMP_LT(jiffies, endtime)) { - /* If we don't have a callback in flight, post one. */ - if (!smp_load_acquire(&rbi.inflight)) { - /* RCU core before ->inflight = 1. */ - smp_store_release(&rbi.inflight, 1); - call_rcu(&rbi.rcu, rcu_torture_boost_cb); - if (jiffies - call_rcu_time > - test_boost_duration * HZ - HZ / 2) { - VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); - n_rcu_torture_boost_failure++; - } - call_rcu_time = jiffies; + while (time_before(jiffies, endtime)) { + // Has current GP gone too long? + if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) + failed = rcu_torture_boost_failed(gp_state, &gp_state_time); + // If we don't have a grace period in flight, start one. + if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) { + gp_state = cur_ops->start_gp_poll(); + gp_initiated = true; + gp_state_time = jiffies; + } + if (stutter_wait("rcu_torture_boost")) { + sched_set_fifo_low(current); + // If the grace period already ended, + // we don't know when that happened, so + // start over. + if (cur_ops->poll_gp_state(gp_state)) + gp_initiated = false; } - stutter_wait("rcu_torture_boost"); if (torture_must_stop()) goto checkwait; } + // In case the grace period extended beyond the end of the loop. + if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state)) + rcu_torture_boost_failed(gp_state, &gp_state_time); + /* * Set the start time of the next test interval. * Yes, this is vulnerable to long delays, but such @@ -831,84 +1363,34 @@ static int rcu_torture_boost(void *arg) * interval. Besides, we are running at RT priority, * so delays should be relatively rare. */ - while (oldstarttime == boost_starttime && - !kthread_should_stop()) { + while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) { if (mutex_trylock(&boost_mutex)) { - boost_starttime = jiffies + - test_boost_interval * HZ; - n_rcu_torture_boosts++; + if (oldstarttime == boost_starttime) { + WRITE_ONCE(boost_starttime, + jiffies + test_boost_interval * HZ); + n_rcu_torture_boosts++; + } mutex_unlock(&boost_mutex); break; } - schedule_timeout_uninterruptible(1); + schedule_timeout_uninterruptible(HZ / 20); } /* Go do the stutter. */ -checkwait: stutter_wait("rcu_torture_boost"); +checkwait: if (stutter_wait("rcu_torture_boost")) + sched_set_fifo_low(current); } while (!torture_must_stop()); +cleanup: /* Clean up and exit. */ - while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) { + while (!kthread_should_stop()) { torture_shutdown_absorb("rcu_torture_boost"); - schedule_timeout_uninterruptible(1); + schedule_timeout_uninterruptible(HZ / 20); } - destroy_rcu_head_on_stack(&rbi.rcu); torture_kthread_stopping("rcu_torture_boost"); return 0; } -static void rcu_torture_cbflood_cb(struct rcu_head *rhp) -{ -} - -/* - * RCU torture callback-flood kthread. Repeatedly induces bursts of calls - * to call_rcu() or analogous, increasing the probability of occurrence - * of callback-overflow corner cases. - */ -static int -rcu_torture_cbflood(void *arg) -{ - int err = 1; - int i; - int j; - struct rcu_head *rhp; - - if (cbflood_n_per_burst > 0 && - cbflood_inter_holdoff > 0 && - cbflood_intra_holdoff > 0 && - cur_ops->call && - cur_ops->cb_barrier) { - rhp = vmalloc(sizeof(*rhp) * - cbflood_n_burst * cbflood_n_per_burst); - err = !rhp; - } - if (err) { - VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM"); - goto wait_for_stop; - } - VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started"); - do { - schedule_timeout_interruptible(cbflood_inter_holdoff); - atomic_long_inc(&n_cbfloods); - WARN_ON(signal_pending(current)); - for (i = 0; i < cbflood_n_burst; i++) { - for (j = 0; j < cbflood_n_per_burst; j++) { - cur_ops->call(&rhp[i * cbflood_n_per_burst + j], - rcu_torture_cbflood_cb); - } - schedule_timeout_interruptible(cbflood_intra_holdoff); - WARN_ON(signal_pending(current)); - } - cur_ops->cb_barrier(); - stutter_wait("rcu_torture_cbflood"); - } while (!torture_must_stop()); - vfree(rhp); -wait_for_stop: - torture_kthread_stopping("rcu_torture_cbflood"); - return 0; -} - /* * RCU torture force-quiescent-state kthread. Repeatedly induces * bursts of calls to force_quiescent_state(), increasing the probability @@ -919,13 +1401,14 @@ rcu_torture_fqs(void *arg) { unsigned long fqs_resume_time; int fqs_burst_remaining; + int oldnice = task_nice(current); VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); do { fqs_resume_time = jiffies + fqs_stutter * HZ; - while (ULONG_CMP_LT(jiffies, fqs_resume_time) && + while (time_before(jiffies, fqs_resume_time) && !kthread_should_stop()) { - schedule_timeout_interruptible(1); + schedule_timeout_interruptible(HZ / 20); } fqs_burst_remaining = fqs_duration; while (fqs_burst_remaining > 0 && @@ -934,12 +1417,159 @@ rcu_torture_fqs(void *arg) udelay(fqs_holdoff); fqs_burst_remaining -= fqs_holdoff; } - stutter_wait("rcu_torture_fqs"); + if (stutter_wait("rcu_torture_fqs")) + sched_set_normal(current, oldnice); } while (!torture_must_stop()); torture_kthread_stopping("rcu_torture_fqs"); return 0; } +// Used by writers to randomly choose from the available grace-period primitives. +static int synctype[ARRAY_SIZE(rcu_torture_writer_state_names)] = { }; +static int nsynctypes; + +/* + * Determine which grace-period primitives are available. + */ +static void rcu_torture_write_types(void) +{ + bool gp_cond1 = gp_cond, gp_cond_exp1 = gp_cond_exp, gp_cond_full1 = gp_cond_full; + bool gp_cond_exp_full1 = gp_cond_exp_full, gp_exp1 = gp_exp, gp_poll_exp1 = gp_poll_exp; + bool gp_poll_exp_full1 = gp_poll_exp_full, gp_normal1 = gp_normal, gp_poll1 = gp_poll; + bool gp_poll_full1 = gp_poll_full, gp_sync1 = gp_sync; + + /* Initialize synctype[] array. If none set, take default. */ + if (!gp_cond1 && + !gp_cond_exp1 && + !gp_cond_full1 && + !gp_cond_exp_full1 && + !gp_exp1 && + !gp_poll_exp1 && + !gp_poll_exp_full1 && + !gp_normal1 && + !gp_poll1 && + !gp_poll_full1 && + !gp_sync1) { + gp_cond1 = true; + gp_cond_exp1 = true; + gp_cond_full1 = true; + gp_cond_exp_full1 = true; + gp_exp1 = true; + gp_poll_exp1 = true; + gp_poll_exp_full1 = true; + gp_normal1 = true; + gp_poll1 = true; + gp_poll_full1 = true; + gp_sync1 = true; + } + if (gp_cond1 && cur_ops->get_gp_state && cur_ops->cond_sync) { + synctype[nsynctypes++] = RTWS_COND_GET; + pr_info("%s: Testing conditional GPs.\n", __func__); + } else if (gp_cond && (!cur_ops->get_gp_state || !cur_ops->cond_sync)) { + pr_alert("%s: gp_cond without primitives.\n", __func__); + } + if (gp_cond_exp1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp) { + synctype[nsynctypes++] = RTWS_COND_GET_EXP; + pr_info("%s: Testing conditional expedited GPs.\n", __func__); + } else if (gp_cond_exp && (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp)) { + pr_alert("%s: gp_cond_exp without primitives.\n", __func__); + } + if (gp_cond_full1 && cur_ops->get_gp_state && cur_ops->cond_sync_full) { + synctype[nsynctypes++] = RTWS_COND_GET_FULL; + pr_info("%s: Testing conditional full-state GPs.\n", __func__); + } else if (gp_cond_full && (!cur_ops->get_gp_state || !cur_ops->cond_sync_full)) { + pr_alert("%s: gp_cond_full without primitives.\n", __func__); + } + if (gp_cond_exp_full1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp_full) { + synctype[nsynctypes++] = RTWS_COND_GET_EXP_FULL; + pr_info("%s: Testing conditional full-state expedited GPs.\n", __func__); + } else if (gp_cond_exp_full && + (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp_full)) { + pr_alert("%s: gp_cond_exp_full without primitives.\n", __func__); + } + if (gp_exp1 && cur_ops->exp_sync) { + synctype[nsynctypes++] = RTWS_EXP_SYNC; + pr_info("%s: Testing expedited GPs.\n", __func__); + } else if (gp_exp && !cur_ops->exp_sync) { + pr_alert("%s: gp_exp without primitives.\n", __func__); + } + if (gp_normal1 && cur_ops->deferred_free) { + synctype[nsynctypes++] = RTWS_DEF_FREE; + pr_info("%s: Testing asynchronous GPs.\n", __func__); + } else if (gp_normal && !cur_ops->deferred_free) { + pr_alert("%s: gp_normal without primitives.\n", __func__); + } + if (gp_poll1 && cur_ops->get_comp_state && cur_ops->same_gp_state && + cur_ops->start_gp_poll && cur_ops->poll_gp_state) { + synctype[nsynctypes++] = RTWS_POLL_GET; + pr_info("%s: Testing polling GPs.\n", __func__); + } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) { + pr_alert("%s: gp_poll without primitives.\n", __func__); + } + if (gp_poll_full1 && cur_ops->get_comp_state_full && cur_ops->same_gp_state_full + && cur_ops->start_gp_poll_full && cur_ops->poll_gp_state_full) { + synctype[nsynctypes++] = RTWS_POLL_GET_FULL; + pr_info("%s: Testing polling full-state GPs.\n", __func__); + } else if (gp_poll_full && (!cur_ops->start_gp_poll_full || !cur_ops->poll_gp_state_full)) { + pr_alert("%s: gp_poll_full without primitives.\n", __func__); + } + if (gp_poll_exp1 && cur_ops->start_gp_poll_exp && cur_ops->poll_gp_state_exp) { + synctype[nsynctypes++] = RTWS_POLL_GET_EXP; + pr_info("%s: Testing polling expedited GPs.\n", __func__); + } else if (gp_poll_exp && (!cur_ops->start_gp_poll_exp || !cur_ops->poll_gp_state_exp)) { + pr_alert("%s: gp_poll_exp without primitives.\n", __func__); + } + if (gp_poll_exp_full1 && cur_ops->start_gp_poll_exp_full && cur_ops->poll_gp_state_full) { + synctype[nsynctypes++] = RTWS_POLL_GET_EXP_FULL; + pr_info("%s: Testing polling full-state expedited GPs.\n", __func__); + } else if (gp_poll_exp_full && + (!cur_ops->start_gp_poll_exp_full || !cur_ops->poll_gp_state_full)) { + pr_alert("%s: gp_poll_exp_full without primitives.\n", __func__); + } + if (gp_sync1 && cur_ops->sync) { + synctype[nsynctypes++] = RTWS_SYNC; + pr_info("%s: Testing normal GPs.\n", __func__); + } else if (gp_sync && !cur_ops->sync) { + pr_alert("%s: gp_sync without primitives.\n", __func__); + } + pr_alert("%s: Testing %d update types.\n", __func__, nsynctypes); + pr_info("%s: gp_cond_wi %d gp_cond_wi_exp %d gp_poll_wi %d gp_poll_wi_exp %d\n", __func__, gp_cond_wi, gp_cond_wi_exp, gp_poll_wi, gp_poll_wi_exp); +} + +/* + * Do the specified rcu_torture_writer() synchronous grace period, + * while also testing out the polled APIs. Note well that the single-CPU + * grace-period optimizations must be accounted for. + */ +static void do_rtws_sync(struct torture_random_state *trsp, void (*sync)(void)) +{ + unsigned long cookie; + struct rcu_gp_oldstate cookie_full; + bool dopoll; + bool dopoll_full; + unsigned long r = torture_random(trsp); + + dopoll = cur_ops->get_gp_state && cur_ops->poll_gp_state && !(r & 0x300); + dopoll_full = cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full && !(r & 0xc00); + if (dopoll || dopoll_full) + cpus_read_lock(); + if (dopoll) + cookie = cur_ops->get_gp_state(); + if (dopoll_full) + cur_ops->get_gp_state_full(&cookie_full); + if (cur_ops->poll_need_2gp && cur_ops->poll_need_2gp(dopoll, dopoll_full)) + sync(); + sync(); + WARN_ONCE(dopoll && !cur_ops->poll_gp_state(cookie), + "%s: Cookie check 3 failed %pS() online %*pbl.", + __func__, sync, cpumask_pr_args(cpu_online_mask)); + WARN_ONCE(dopoll_full && !cur_ops->poll_gp_state_full(&cookie_full), + "%s: Cookie check 4 failed %pS() online %*pbl", + __func__, sync, cpumask_pr_args(cpu_online_mask)); + if (dopoll || dopoll_full) + cpus_read_unlock(); +} + /* * RCU torture writer kthread. Repeatedly substitutes a new structure * for that pointed to by rcu_torture_current, freeing the old structure @@ -948,50 +1578,40 @@ rcu_torture_fqs(void *arg) static int rcu_torture_writer(void *arg) { + bool booting_still = false; bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); + unsigned long cookie; + struct rcu_gp_oldstate cookie_full; int expediting = 0; unsigned long gp_snap; - bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal; - bool gp_sync1 = gp_sync; + unsigned long gp_snap1; + struct rcu_gp_oldstate gp_snap_full; + struct rcu_gp_oldstate gp_snap1_full; int i; + int idx; + unsigned long j; + int oldnice = task_nice(current); + struct rcu_gp_oldstate *rgo = NULL; + int rgo_size = 0; struct rcu_torture *rp; struct rcu_torture *old_rp; static DEFINE_TORTURE_RANDOM(rand); - int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC, - RTWS_COND_GET, RTWS_SYNC }; - int nsynctypes = 0; - + unsigned long stallsdone = jiffies; + bool stutter_waited; + unsigned long *ulo = NULL; + int ulo_size = 0; + + // If a new stall test is added, this must be adjusted. + if (stall_cpu_holdoff + stall_gp_kthread + stall_cpu) + stallsdone += (stall_cpu_holdoff + stall_gp_kthread + stall_cpu + 60) * + HZ * (stall_cpu_repeat + 1); VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); - if (!can_expedite) { + if (!can_expedite) pr_alert("%s" TORTURE_FLAG - " GP expediting controlled from boot/sysfs for %s,\n", + " GP expediting controlled from boot/sysfs for %s.\n", torture_type, cur_ops->name); - pr_alert("%s" TORTURE_FLAG - " Disabled dynamic grace-period expediting.\n", - torture_type); - } - - /* Initialize synctype[] array. If none set, take default. */ - if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1) - gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true; - if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) - synctype[nsynctypes++] = RTWS_COND_GET; - else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) - pr_alert("rcu_torture_writer: gp_cond without primitives.\n"); - if (gp_exp1 && cur_ops->exp_sync) - synctype[nsynctypes++] = RTWS_EXP_SYNC; - else if (gp_exp && !cur_ops->exp_sync) - pr_alert("rcu_torture_writer: gp_exp without primitives.\n"); - if (gp_normal1 && cur_ops->deferred_free) - synctype[nsynctypes++] = RTWS_DEF_FREE; - else if (gp_normal && !cur_ops->deferred_free) - pr_alert("rcu_torture_writer: gp_normal without primitives.\n"); - if (gp_sync1 && cur_ops->sync) - synctype[nsynctypes++] = RTWS_SYNC; - else if (gp_sync && !cur_ops->sync) - pr_alert("rcu_torture_writer: gp_sync without primitives.\n"); if (WARN_ONCE(nsynctypes == 0, - "rcu_torture_writer: No update-side primitives.\n")) { + "%s: No update-side primitives.\n", __func__)) { /* * No updates primitives, so don't try updating. * The resulting test won't be testing much, hence the @@ -999,15 +1619,37 @@ rcu_torture_writer(void *arg) */ rcu_torture_writer_state = RTWS_STOPPING; torture_kthread_stopping("rcu_torture_writer"); + return 0; } + if (cur_ops->poll_active > 0) { + ulo = kcalloc(cur_ops->poll_active, sizeof(*ulo), GFP_KERNEL); + if (!WARN_ON(!ulo)) + ulo_size = cur_ops->poll_active; + } + if (cur_ops->poll_active_full > 0) { + rgo = kcalloc(cur_ops->poll_active_full, sizeof(*rgo), GFP_KERNEL); + if (!WARN_ON(!rgo)) + rgo_size = cur_ops->poll_active_full; + } + + // If the system is still booting, let it finish. + j = jiffies; + while (!torture_must_stop() && !rcu_inkernel_boot_has_ended()) { + booting_still = true; + schedule_timeout_interruptible(HZ); + } + if (booting_still) + pr_alert("%s" TORTURE_FLAG " Waited %lu jiffies for boot to complete.\n", + torture_type, jiffies - j); do { rcu_torture_writer_state = RTWS_FIXED_DELAY; - schedule_timeout_uninterruptible(1); + torture_hrtimeout_us(500, 1000, &rand); rp = rcu_torture_alloc(); if (rp == NULL) continue; rp->rtort_pipe_count = 0; + ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count); rcu_torture_writer_state = RTWS_DELAY; udelay(torture_random(&rand) & 0x3ff); rcu_torture_writer_state = RTWS_REPLACE; @@ -1021,7 +1663,41 @@ rcu_torture_writer(void *arg) if (i > RCU_TORTURE_PIPE_LEN) i = RCU_TORTURE_PIPE_LEN; atomic_inc(&rcu_torture_wcount[i]); - old_rp->rtort_pipe_count++; + WRITE_ONCE(old_rp->rtort_pipe_count, + old_rp->rtort_pipe_count + 1); + ASSERT_EXCLUSIVE_WRITER(old_rp->rtort_pipe_count); + + // Make sure readers block polled grace periods. + if (cur_ops->get_gp_state && cur_ops->poll_gp_state) { + idx = cur_ops->readlock(); + cookie = cur_ops->get_gp_state(); + WARN_ONCE(cur_ops->poll_gp_state(cookie), + "%s: Cookie check 1 failed %s(%d) %lu->%lu\n", + __func__, + rcu_torture_writer_state_getname(), + rcu_torture_writer_state, + cookie, cur_ops->get_gp_state()); + if (cur_ops->get_comp_state) { + cookie = cur_ops->get_comp_state(); + WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie)); + } + cur_ops->readunlock(idx); + } + if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) { + idx = cur_ops->readlock(); + cur_ops->get_gp_state_full(&cookie_full); + WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full), + "%s: Cookie check 5 failed %s(%d) online %*pbl\n", + __func__, + rcu_torture_writer_state_getname(), + rcu_torture_writer_state, + cpumask_pr_args(cpu_online_mask)); + if (cur_ops->get_comp_state_full) { + cur_ops->get_comp_state_full(&cookie_full); + WARN_ON_ONCE(!cur_ops->poll_gp_state_full(&cookie_full)); + } + cur_ops->readunlock(idx); + } switch (synctype[torture_random(&rand) % nsynctypes]) { case RTWS_DEF_FREE: rcu_torture_writer_state = RTWS_DEF_FREE; @@ -1029,23 +1705,111 @@ rcu_torture_writer(void *arg) break; case RTWS_EXP_SYNC: rcu_torture_writer_state = RTWS_EXP_SYNC; - cur_ops->exp_sync(); + do_rtws_sync(&rand, cur_ops->exp_sync); rcu_torture_pipe_update(old_rp); break; case RTWS_COND_GET: rcu_torture_writer_state = RTWS_COND_GET; - gp_snap = cur_ops->get_state(); - i = torture_random(&rand) % 16; - if (i != 0) - schedule_timeout_interruptible(i); - udelay(torture_random(&rand) % 1000); + gp_snap = cur_ops->get_gp_state(); + torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, + 1000, &rand); rcu_torture_writer_state = RTWS_COND_SYNC; cur_ops->cond_sync(gp_snap); rcu_torture_pipe_update(old_rp); break; + case RTWS_COND_GET_EXP: + rcu_torture_writer_state = RTWS_COND_GET_EXP; + gp_snap = cur_ops->get_gp_state_exp(); + torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, + 1000, &rand); + rcu_torture_writer_state = RTWS_COND_SYNC_EXP; + cur_ops->cond_sync_exp(gp_snap); + rcu_torture_pipe_update(old_rp); + break; + case RTWS_COND_GET_FULL: + rcu_torture_writer_state = RTWS_COND_GET_FULL; + cur_ops->get_gp_state_full(&gp_snap_full); + torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi, + 1000, &rand); + rcu_torture_writer_state = RTWS_COND_SYNC_FULL; + cur_ops->cond_sync_full(&gp_snap_full); + rcu_torture_pipe_update(old_rp); + break; + case RTWS_COND_GET_EXP_FULL: + rcu_torture_writer_state = RTWS_COND_GET_EXP_FULL; + cur_ops->get_gp_state_full(&gp_snap_full); + torture_hrtimeout_us(torture_random(&rand) % gp_cond_wi_exp, + 1000, &rand); + rcu_torture_writer_state = RTWS_COND_SYNC_EXP_FULL; + cur_ops->cond_sync_exp_full(&gp_snap_full); + rcu_torture_pipe_update(old_rp); + break; + case RTWS_POLL_GET: + rcu_torture_writer_state = RTWS_POLL_GET; + for (i = 0; i < ulo_size; i++) + ulo[i] = cur_ops->get_comp_state(); + gp_snap = cur_ops->start_gp_poll(); + rcu_torture_writer_state = RTWS_POLL_WAIT; + if (cur_ops->exp_current && !torture_random(&rand) % 0xff) + cur_ops->exp_current(); + while (!cur_ops->poll_gp_state(gp_snap)) { + gp_snap1 = cur_ops->get_gp_state(); + for (i = 0; i < ulo_size; i++) + if (cur_ops->poll_gp_state(ulo[i]) || + cur_ops->same_gp_state(ulo[i], gp_snap1)) { + ulo[i] = gp_snap1; + break; + } + WARN_ON_ONCE(ulo_size > 0 && i >= ulo_size); + torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, + 1000, &rand); + } + rcu_torture_pipe_update(old_rp); + break; + case RTWS_POLL_GET_FULL: + rcu_torture_writer_state = RTWS_POLL_GET_FULL; + for (i = 0; i < rgo_size; i++) + cur_ops->get_comp_state_full(&rgo[i]); + cur_ops->start_gp_poll_full(&gp_snap_full); + rcu_torture_writer_state = RTWS_POLL_WAIT_FULL; + if (cur_ops->exp_current && !torture_random(&rand) % 0xff) + cur_ops->exp_current(); + while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { + cur_ops->get_gp_state_full(&gp_snap1_full); + for (i = 0; i < rgo_size; i++) + if (cur_ops->poll_gp_state_full(&rgo[i]) || + cur_ops->same_gp_state_full(&rgo[i], + &gp_snap1_full)) { + rgo[i] = gp_snap1_full; + break; + } + WARN_ON_ONCE(rgo_size > 0 && i >= rgo_size); + torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi, + 1000, &rand); + } + rcu_torture_pipe_update(old_rp); + break; + case RTWS_POLL_GET_EXP: + rcu_torture_writer_state = RTWS_POLL_GET_EXP; + gp_snap = cur_ops->start_gp_poll_exp(); + rcu_torture_writer_state = RTWS_POLL_WAIT_EXP; + while (!cur_ops->poll_gp_state_exp(gp_snap)) + torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, + 1000, &rand); + rcu_torture_pipe_update(old_rp); + break; + case RTWS_POLL_GET_EXP_FULL: + rcu_torture_writer_state = RTWS_POLL_GET_EXP_FULL; + cur_ops->start_gp_poll_exp_full(&gp_snap_full); + rcu_torture_writer_state = RTWS_POLL_WAIT_EXP_FULL; + while (!cur_ops->poll_gp_state_full(&gp_snap_full)) + torture_hrtimeout_us(torture_random(&rand) % gp_poll_wi_exp, + 1000, &rand); + rcu_torture_pipe_update(old_rp); + break; case RTWS_SYNC: rcu_torture_writer_state = RTWS_SYNC; - cur_ops->sync(); + do_rtws_sync(&rand, cur_ops->sync); rcu_torture_pipe_update(old_rp); break; default: @@ -1053,7 +1817,8 @@ rcu_torture_writer(void *arg) break; } } - rcutorture_record_progress(++rcu_torture_current_version); + WRITE_ONCE(rcu_torture_current_version, + rcu_torture_current_version + 1); /* Cycle through nesting levels of rcu_expedite_gp() calls. */ if (can_expedite && !(torture_random(&rand) & 0xff & (!!expediting - 1))) { @@ -1064,16 +1829,43 @@ rcu_torture_writer(void *arg) rcu_unexpedite_gp(); if (++expediting > 3) expediting = -expediting; + } else if (!can_expedite) { /* Disabled during boot, recheck. */ + can_expedite = !rcu_gp_is_expedited() && + !rcu_gp_is_normal(); } rcu_torture_writer_state = RTWS_STUTTER; - stutter_wait("rcu_torture_writer"); + stutter_waited = stutter_wait("rcu_torture_writer"); + if (stutter_waited && + !atomic_read(&rcu_fwd_cb_nodelay) && + !cur_ops->slow_gps && + !torture_must_stop() && + time_after(jiffies, stallsdone)) + for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) + if (list_empty(&rcu_tortures[i].rtort_free) && + rcu_access_pointer(rcu_torture_current) != &rcu_tortures[i]) { + tracing_off(); + if (cur_ops->gp_kthread_dbg) + cur_ops->gp_kthread_dbg(); + WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); + rcu_ftrace_dump(DUMP_ALL); + break; + } + if (stutter_waited) + sched_set_normal(current, oldnice); } while (!torture_must_stop()); + rcu_torture_current = NULL; // Let stats task know that we are done. /* Reset expediting back to unexpedited. */ if (expediting > 0) expediting = -expediting; while (can_expedite && expediting++ < 0) rcu_unexpedite_gp(); WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); + if (!can_expedite) + pr_alert("%s" TORTURE_FLAG + " Dynamic grace-period expediting was disabled.\n", + torture_type); + kfree(ulo); + kfree(rgo); rcu_torture_writer_state = RTWS_STOPPING; torture_kthread_stopping("rcu_torture_writer"); return 0; @@ -1086,26 +1878,99 @@ rcu_torture_writer(void *arg) static int rcu_torture_fakewriter(void *arg) { + unsigned long gp_snap; + struct rcu_gp_oldstate gp_snap_full; DEFINE_TORTURE_RANDOM(rand); VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); set_user_nice(current, MAX_NICE); + if (WARN_ONCE(nsynctypes == 0, + "%s: No update-side primitives.\n", __func__)) { + /* + * No updates primitives, so don't try updating. + * The resulting test won't be testing much, hence the + * above WARN_ONCE(). + */ + torture_kthread_stopping("rcu_torture_fakewriter"); + return 0; + } + do { - schedule_timeout_uninterruptible(1 + torture_random(&rand)%10); - udelay(torture_random(&rand) & 0x3ff); + torture_hrtimeout_jiffies(torture_random(&rand) % 10, &rand); if (cur_ops->cb_barrier != NULL && - torture_random(&rand) % (nfakewriters * 8) == 0) { + torture_random(&rand) % (nrealfakewriters * 8) == 0) { cur_ops->cb_barrier(); - } else if (gp_normal == gp_exp) { - if (torture_random(&rand) & 0x80) - cur_ops->sync(); - else - cur_ops->exp_sync(); - } else if (gp_normal) { - cur_ops->sync(); } else { - cur_ops->exp_sync(); + switch (synctype[torture_random(&rand) % nsynctypes]) { + case RTWS_DEF_FREE: + break; + case RTWS_EXP_SYNC: + cur_ops->exp_sync(); + break; + case RTWS_COND_GET: + gp_snap = cur_ops->get_gp_state(); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); + cur_ops->cond_sync(gp_snap); + break; + case RTWS_COND_GET_EXP: + gp_snap = cur_ops->get_gp_state_exp(); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); + cur_ops->cond_sync_exp(gp_snap); + break; + case RTWS_COND_GET_FULL: + cur_ops->get_gp_state_full(&gp_snap_full); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); + cur_ops->cond_sync_full(&gp_snap_full); + break; + case RTWS_COND_GET_EXP_FULL: + cur_ops->get_gp_state_full(&gp_snap_full); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); + cur_ops->cond_sync_exp_full(&gp_snap_full); + break; + case RTWS_POLL_GET: + if (cur_ops->start_poll_irqsoff) + local_irq_disable(); + gp_snap = cur_ops->start_gp_poll(); + if (cur_ops->start_poll_irqsoff) + local_irq_enable(); + while (!cur_ops->poll_gp_state(gp_snap)) { + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); + } + break; + case RTWS_POLL_GET_FULL: + if (cur_ops->start_poll_irqsoff) + local_irq_disable(); + cur_ops->start_gp_poll_full(&gp_snap_full); + if (cur_ops->start_poll_irqsoff) + local_irq_enable(); + while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); + } + break; + case RTWS_POLL_GET_EXP: + gp_snap = cur_ops->start_gp_poll_exp(); + while (!cur_ops->poll_gp_state_exp(gp_snap)) { + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); + } + break; + case RTWS_POLL_GET_EXP_FULL: + cur_ops->start_gp_poll_exp_full(&gp_snap_full); + while (!cur_ops->poll_gp_state_full(&gp_snap_full)) { + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); + } + break; + case RTWS_SYNC: + cur_ops->sync(); + break; + default: + WARN_ON_ONCE(1); + break; + } } stutter_wait("rcu_torture_fakewriter"); } while (!torture_must_stop()); @@ -1114,68 +1979,492 @@ rcu_torture_fakewriter(void *arg) return 0; } +static void rcu_torture_timer_cb(struct rcu_head *rhp) +{ + kfree(rhp); +} + +// Set up and carry out testing of RCU's global memory ordering +static void rcu_torture_reader_do_mbchk(long myid, struct rcu_torture *rtp, + struct torture_random_state *trsp) +{ + unsigned long loops; + int noc = torture_num_online_cpus(); + int rdrchked; + int rdrchker; + struct rcu_torture_reader_check *rtrcp; // Me. + struct rcu_torture_reader_check *rtrcp_assigner; // Assigned us to do checking. + struct rcu_torture_reader_check *rtrcp_chked; // Reader being checked. + struct rcu_torture_reader_check *rtrcp_chker; // Reader doing checking when not me. + + if (myid < 0) + return; // Don't try this from timer handlers. + + // Increment my counter. + rtrcp = &rcu_torture_reader_mbchk[myid]; + WRITE_ONCE(rtrcp->rtc_myloops, rtrcp->rtc_myloops + 1); + + // Attempt to assign someone else some checking work. + rdrchked = torture_random(trsp) % nrealreaders; + rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; + rdrchker = torture_random(trsp) % nrealreaders; + rtrcp_chker = &rcu_torture_reader_mbchk[rdrchker]; + if (rdrchked != myid && rdrchked != rdrchker && noc >= rdrchked && noc >= rdrchker && + smp_load_acquire(&rtrcp->rtc_chkrdr) < 0 && // Pairs with smp_store_release below. + !READ_ONCE(rtp->rtort_chkp) && + !smp_load_acquire(&rtrcp_chker->rtc_assigner)) { // Pairs with smp_store_release below. + rtrcp->rtc_chkloops = READ_ONCE(rtrcp_chked->rtc_myloops); + WARN_ON_ONCE(rtrcp->rtc_chkrdr >= 0); + rtrcp->rtc_chkrdr = rdrchked; + WARN_ON_ONCE(rtrcp->rtc_ready); // This gets set after the grace period ends. + if (cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, NULL, rtrcp) || + cmpxchg_relaxed(&rtp->rtort_chkp, NULL, rtrcp)) + (void)cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, rtrcp, NULL); // Back out. + } + + // If assigned some completed work, do it! + rtrcp_assigner = READ_ONCE(rtrcp->rtc_assigner); + if (!rtrcp_assigner || !smp_load_acquire(&rtrcp_assigner->rtc_ready)) + return; // No work or work not yet ready. + rdrchked = rtrcp_assigner->rtc_chkrdr; + if (WARN_ON_ONCE(rdrchked < 0)) + return; + rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked]; + loops = READ_ONCE(rtrcp_chked->rtc_myloops); + atomic_inc(&n_rcu_torture_mbchk_tries); + if (ULONG_CMP_LT(loops, rtrcp_assigner->rtc_chkloops)) + atomic_inc(&n_rcu_torture_mbchk_fail); + rtrcp_assigner->rtc_chkloops = loops + ULONG_MAX / 2; + rtrcp_assigner->rtc_ready = 0; + smp_store_release(&rtrcp->rtc_assigner, NULL); // Someone else can assign us work. + smp_store_release(&rtrcp_assigner->rtc_chkrdr, -1); // Assigner can again assign. +} + +// Verify the specified RCUTORTURE_RDR* state. +#define ROEC_ARGS "%s %s: Current %#x To add %#x To remove %#x preempt_count() %#x\n", __func__, s, curstate, new, old, preempt_count() +static void rcutorture_one_extend_check(char *s, int curstate, int new, int old) +{ + int mask; + + if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE) || in_nmi()) + return; + + WARN_ONCE(!(curstate & RCUTORTURE_RDR_IRQ) && irqs_disabled() && !in_hardirq(), ROEC_ARGS); + WARN_ONCE((curstate & RCUTORTURE_RDR_IRQ) && !irqs_disabled(), ROEC_ARGS); + + // If CONFIG_PREEMPT_COUNT=n, further checks are unreliable. + if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) + return; + + WARN_ONCE((curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && + !softirq_count(), ROEC_ARGS); + WARN_ONCE((curstate & (RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED)) && + !(preempt_count() & PREEMPT_MASK), ROEC_ARGS); + WARN_ONCE(cur_ops->readlock_nesting && + (curstate & (RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2)) && + cur_ops->readlock_nesting() == 0, ROEC_ARGS); + + // Interrupt handlers have all sorts of stuff disabled, so ignore + // unintended disabling. + if (in_serving_softirq() || in_hardirq()) + return; + + WARN_ONCE(cur_ops->extendables && + !(curstate & (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH)) && + softirq_count(), ROEC_ARGS); + + /* + * non-preemptible RCU in a preemptible kernel uses preempt_disable() + * as rcu_read_lock(). + */ + mask = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; + if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) + mask |= RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; + + WARN_ONCE(cur_ops->extendables && !(curstate & mask) && + (preempt_count() & PREEMPT_MASK), ROEC_ARGS); + + /* + * non-preemptible RCU in a preemptible kernel uses "preempt_count() & + * PREEMPT_MASK" as ->readlock_nesting(). + */ + mask = RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; + if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) + mask |= RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; + + if (IS_ENABLED(CONFIG_PREEMPT_RT) && softirq_count()) + mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; + + WARN_ONCE(cur_ops->readlock_nesting && !(curstate & mask) && + cur_ops->readlock_nesting() > 0, ROEC_ARGS); +} + /* - * RCU torture reader from timer handler. Dereferences rcu_torture_current, - * incrementing the corresponding element of the pipeline array. The - * counter in the element should never be greater than 1, otherwise, the - * RCU implementation is broken. + * Do one extension of an RCU read-side critical section using the + * current reader state in readstate (set to zero for initial entry + * to extended critical section), set the new state as specified by + * newstate (set to zero for final exit from extended critical section), + * and random-number-generator state in trsp. If this is neither the + * beginning or end of the critical section and if there was actually a + * change, do a ->read_delay(). */ -static void rcu_torture_timer(unsigned long unused) +static void rcutorture_one_extend(int *readstate, int newstate, struct torture_random_state *trsp, + struct rt_read_seg *rtrsp) { - int idx; + bool first; + unsigned long flags; + int idxnew1 = -1; + int idxnew2 = -1; + int idxold1 = *readstate; + int idxold2 = idxold1; + int statesnew = ~*readstate & newstate; + int statesold = *readstate & ~newstate; + + first = idxold1 == 0; + WARN_ON_ONCE(idxold2 < 0); + WARN_ON_ONCE(idxold2 & ~(RCUTORTURE_RDR_ALLBITS | RCUTORTURE_RDR_UPDOWN)); + rcutorture_one_extend_check("before change", idxold1, statesnew, statesold); + rtrsp->rt_readstate = newstate; + + /* First, put new protection in place to avoid critical-section gap. */ + if (statesnew & RCUTORTURE_RDR_BH) + local_bh_disable(); + if (statesnew & RCUTORTURE_RDR_RBH) + rcu_read_lock_bh(); + if (statesnew & RCUTORTURE_RDR_IRQ) + local_irq_disable(); + if (statesnew & RCUTORTURE_RDR_PREEMPT) + preempt_disable(); + if (statesnew & RCUTORTURE_RDR_SCHED) + rcu_read_lock_sched(); + if (statesnew & RCUTORTURE_RDR_RCU_1) + idxnew1 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; + if (statesnew & RCUTORTURE_RDR_RCU_2) + idxnew2 = (cur_ops->readlock() << RCUTORTURE_RDR_SHIFT_2) & RCUTORTURE_RDR_MASK_2; + + // Complain unless both the old and the new protection is in place. + rcutorture_one_extend_check("during change", idxold1 | statesnew, statesnew, statesold); + + // Sample CPU under both sets of protections to reduce confusion. + if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { + int cpu = raw_smp_processor_id(); + rtrsp->rt_cpu = cpu; + if (!first) { + rtrsp[-1].rt_end_cpu = cpu; + if (cur_ops->reader_blocked) + rtrsp[-1].rt_preempted = cur_ops->reader_blocked(); + } + } + // Sample grace-period sequence number, as good a place as any. + if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && cur_ops->gather_gp_seqs) { + rtrsp->rt_gp_seq = cur_ops->gather_gp_seqs(); + rtrsp->rt_ts = ktime_get_mono_fast_ns(); + if (!first) + rtrsp[-1].rt_gp_seq_end = rtrsp->rt_gp_seq; + } + + /* + * Next, remove old protection, in decreasing order of strength + * to avoid unlock paths that aren't safe in the stronger + * context. Namely: BH can not be enabled with disabled interrupts. + * Additionally PREEMPT_RT requires that BH is enabled in preemptible + * context. + */ + if (statesold & RCUTORTURE_RDR_IRQ) + local_irq_enable(); + if (statesold & RCUTORTURE_RDR_PREEMPT) + preempt_enable(); + if (statesold & RCUTORTURE_RDR_SCHED) + rcu_read_unlock_sched(); + if (statesold & RCUTORTURE_RDR_BH) + local_bh_enable(); + if (statesold & RCUTORTURE_RDR_RBH) + rcu_read_unlock_bh(); + if (statesold & RCUTORTURE_RDR_RCU_2) { + cur_ops->readunlock((idxold2 & RCUTORTURE_RDR_MASK_2) >> RCUTORTURE_RDR_SHIFT_2); + WARN_ON_ONCE(idxnew2 != -1); + idxold2 = 0; + } + if (statesold & RCUTORTURE_RDR_RCU_1) { + bool lockit; + + lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff); + if (lockit) + raw_spin_lock_irqsave(¤t->pi_lock, flags); + cur_ops->readunlock((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); + WARN_ON_ONCE(idxnew1 != -1); + idxold1 = 0; + if (lockit) + raw_spin_unlock_irqrestore(¤t->pi_lock, flags); + } + if (statesold & RCUTORTURE_RDR_UPDOWN) { + cur_ops->up_read((idxold1 & RCUTORTURE_RDR_MASK_1) >> RCUTORTURE_RDR_SHIFT_1); + WARN_ON_ONCE(idxnew1 != -1); + idxold1 = 0; + } + + /* Delay if neither beginning nor end and there was a change. */ + if ((statesnew || statesold) && *readstate && newstate) + cur_ops->read_delay(trsp, rtrsp); + + /* Update the reader state. */ + if (idxnew1 == -1) + idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1; + WARN_ON_ONCE(idxnew1 < 0); + if (idxnew2 == -1) + idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2; + WARN_ON_ONCE(idxnew2 < 0); + *readstate = idxnew1 | idxnew2 | newstate; + WARN_ON_ONCE(*readstate < 0); + if (WARN_ON_ONCE(*readstate & ~RCUTORTURE_RDR_ALLBITS)) + pr_info("Unexpected readstate value of %#x\n", *readstate); + rcutorture_one_extend_check("after change", *readstate, statesnew, statesold); +} + +/* Return the biggest extendables mask given current RCU and boot parameters. */ +static int rcutorture_extend_mask_max(void) +{ + int mask; + + WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); + mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; + mask = mask | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2; + return mask; +} + +/* Return a random protection state mask, but with at least one bit set. */ +static int +rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) +{ + int mask = rcutorture_extend_mask_max(); + unsigned long randmask1 = torture_random(trsp); + unsigned long randmask2 = randmask1 >> 3; + unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED; + unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ; + unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; + + WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1); // Can't have reader idx bits. + /* Mostly only one bit (need preemption!), sometimes lots of bits. */ + if (!(randmask1 & 0x7)) + mask = mask & randmask2; + else + mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); + + // Can't have nested RCU reader without outer RCU reader. + if (!(mask & RCUTORTURE_RDR_RCU_1) && (mask & RCUTORTURE_RDR_RCU_2)) { + if (oldmask & RCUTORTURE_RDR_RCU_1) + mask &= ~RCUTORTURE_RDR_RCU_2; + else + mask |= RCUTORTURE_RDR_RCU_1; + } + + /* + * Can't enable bh w/irq disabled. + */ + if (mask & RCUTORTURE_RDR_IRQ) + mask |= oldmask & bhs; + + /* + * Ideally these sequences would be detected in debug builds + * (regardless of RT), but until then don't stop testing + * them on non-RT. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + /* Can't modify BH in atomic context */ + if (oldmask & preempts_irq) + mask &= ~bhs; + if ((oldmask | mask) & preempts_irq) + mask |= oldmask & bhs; + } + + return mask ?: RCUTORTURE_RDR_RCU_1; +} + +/* + * Do a randomly selected number of extensions of an existing RCU read-side + * critical section. + */ +static struct rt_read_seg * +rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, struct rt_read_seg *rtrsp) +{ + int i; + int j; + int mask = rcutorture_extend_mask_max(); + + WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ + if (!((mask - 1) & mask)) + return rtrsp; /* Current RCU reader not extendable. */ + /* Bias towards larger numbers of loops. */ + i = torture_random(trsp); + i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; + for (j = 0; j < i; j++) { + mask = rcutorture_extend_mask(*readstate, trsp); + WARN_ON_ONCE(mask & RCUTORTURE_RDR_UPDOWN); + rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); + } + return &rtrsp[j]; +} + +struct rcu_torture_one_read_state { + bool checkpolling; + unsigned long cookie; + struct rcu_gp_oldstate cookie_full; unsigned long started; - unsigned long completed; - static DEFINE_TORTURE_RANDOM(rand); - static DEFINE_SPINLOCK(rand_lock); struct rcu_torture *p; - int pipe_count; + int readstate; + struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS]; + struct rt_read_seg *rtrsp; unsigned long long ts; +}; - idx = cur_ops->readlock(); - if (cur_ops->started) - started = cur_ops->started(); - else - started = cur_ops->completed(); - ts = rcu_trace_clock_local(); - p = rcu_dereference_check(rcu_torture_current, - rcu_read_lock_bh_held() || - rcu_read_lock_sched_held() || - srcu_read_lock_held(srcu_ctlp) || - torturing_tasks()); - if (p == NULL) { - /* Leave because rcu_torture_writer is not yet underway */ - cur_ops->readunlock(idx); - return; +static void init_rcu_torture_one_read_state(struct rcu_torture_one_read_state *rtorsp, + struct torture_random_state *trsp) +{ + memset(rtorsp, 0, sizeof(*rtorsp)); + rtorsp->checkpolling = !(torture_random(trsp) & 0xfff); + rtorsp->rtrsp = &rtorsp->rtseg[0]; +} + +/* + * Set up the first segment of a series of overlapping read-side + * critical sections. The caller must have actually initiated the + * outermost read-side critical section. + */ +static bool rcu_torture_one_read_start(struct rcu_torture_one_read_state *rtorsp, + struct torture_random_state *trsp, long myid) +{ + if (rtorsp->checkpolling) { + if (cur_ops->get_gp_state && cur_ops->poll_gp_state) + rtorsp->cookie = cur_ops->get_gp_state(); + if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) + cur_ops->get_gp_state_full(&rtorsp->cookie_full); + } + rtorsp->started = cur_ops->get_gp_seq(); + rtorsp->ts = rcu_trace_clock_local(); + rtorsp->p = rcu_dereference_check(rcu_torture_current, + !cur_ops->readlock_held || cur_ops->readlock_held() || + (rtorsp->readstate & RCUTORTURE_RDR_UPDOWN)); + if (rtorsp->p == NULL) { + /* Wait for rcu_torture_writer to get underway */ + rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); + return false; } - if (p->rtort_mbtest == 0) + if (rtorsp->p->rtort_mbtest == 0) atomic_inc(&n_rcu_torture_mberror); - spin_lock(&rand_lock); - cur_ops->read_delay(&rand); - n_rcu_torture_timers++; - spin_unlock(&rand_lock); + rcu_torture_reader_do_mbchk(myid, rtorsp->p, trsp); + return true; +} + +/* + * Complete the last segment of a series of overlapping read-side + * critical sections and check for errors. + */ +static void rcu_torture_one_read_end(struct rcu_torture_one_read_state *rtorsp, + struct torture_random_state *trsp) +{ + int i; + unsigned long completed; + int pipe_count; + bool preempted = false; + struct rt_read_seg *rtrsp1; + preempt_disable(); - pipe_count = p->rtort_pipe_count; + pipe_count = READ_ONCE(rtorsp->p->rtort_pipe_count); if (pipe_count > RCU_TORTURE_PIPE_LEN) { - /* Should not happen, but... */ + // Should not happen in a correct RCU implementation, + // happens quite often for torture_type=busted. pipe_count = RCU_TORTURE_PIPE_LEN; } - completed = cur_ops->completed(); + completed = cur_ops->get_gp_seq(); if (pipe_count > 1) { - do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, - started, completed); + do_trace_rcu_torture_read(cur_ops->name, &rtorsp->p->rtort_rcu, + rtorsp->ts, rtorsp->started, completed); rcu_ftrace_dump(DUMP_ALL); } __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = completed - started; - if (cur_ops->started) - completed++; + completed = rcutorture_seq_diff(completed, rtorsp->started); if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; } __this_cpu_inc(rcu_torture_batch[completed]); preempt_enable(); - cur_ops->readunlock(idx); + if (rtorsp->checkpolling) { + if (cur_ops->get_gp_state && cur_ops->poll_gp_state) + WARN_ONCE(cur_ops->poll_gp_state(rtorsp->cookie), + "%s: Cookie check 2 failed %s(%d) %lu->%lu\n", + __func__, + rcu_torture_writer_state_getname(), + rcu_torture_writer_state, + rtorsp->cookie, cur_ops->get_gp_state()); + if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) + WARN_ONCE(cur_ops->poll_gp_state_full(&rtorsp->cookie_full), + "%s: Cookie check 6 failed %s(%d) online %*pbl\n", + __func__, + rcu_torture_writer_state_getname(), + rcu_torture_writer_state, + cpumask_pr_args(cpu_online_mask)); + } + if (cur_ops->reader_blocked) + preempted = cur_ops->reader_blocked(); + rcutorture_one_extend(&rtorsp->readstate, 0, trsp, rtorsp->rtrsp); + WARN_ON_ONCE(rtorsp->readstate); + // This next splat is expected behavior if leakpointer, especially + // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. + WARN_ON_ONCE(leakpointer && READ_ONCE(rtorsp->p->rtort_pipe_count) > 1); + + /* If error or close call, record the sequence of reader protections. */ + if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { + i = 0; + for (rtrsp1 = &rtorsp->rtseg[0]; rtrsp1 < rtorsp->rtrsp; rtrsp1++) + err_segs[i++] = *rtrsp1; + rt_read_nsegs = i; + rt_read_preempted = preempted; + } +} + +/* + * Do one read-side critical section, returning false if there was + * no data to read. Can be invoked both from process context and + * from a timer handler. + */ +static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) +{ + int newstate; + struct rcu_torture_one_read_state rtors; + + WARN_ON_ONCE(!rcu_is_watching()); + init_rcu_torture_one_read_state(&rtors, trsp); + newstate = rcutorture_extend_mask(rtors.readstate, trsp); + WARN_ON_ONCE(newstate & RCUTORTURE_RDR_UPDOWN); + rcutorture_one_extend(&rtors.readstate, newstate, trsp, rtors.rtrsp++); + if (!rcu_torture_one_read_start(&rtors, trsp, myid)) + return false; + rtors.rtrsp = rcutorture_loop_extend(&rtors.readstate, trsp, rtors.rtrsp); + rcu_torture_one_read_end(&rtors, trsp); + return true; +} + +static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); + +/* + * RCU torture reader from timer handler. Dereferences rcu_torture_current, + * incrementing the corresponding element of the pipeline array. The + * counter in the element should never be greater than 1, otherwise, the + * RCU implementation is broken. + */ +static void rcu_torture_timer(struct timer_list *unused) +{ + atomic_long_inc(&n_rcu_torture_timers); + (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1); + + /* Test call_rcu() invocation from interrupt handler. */ + if (cur_ops->call) { + struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT); + + if (rhp) + cur_ops->call(rhp, rcu_torture_timer_cb); + } } /* @@ -1187,78 +2476,235 @@ static void rcu_torture_timer(unsigned long unused) static int rcu_torture_reader(void *arg) { - unsigned long started; - unsigned long completed; - int idx; + unsigned long lastsleep = jiffies; + long myid = (long)arg; + int mynumonline = myid; DEFINE_TORTURE_RANDOM(rand); - struct rcu_torture *p; - int pipe_count; struct timer_list t; - unsigned long long ts; VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); set_user_nice(current, MAX_NICE); if (irqreader && cur_ops->irq_capable) - setup_timer_on_stack(&t, rcu_torture_timer, 0); - + timer_setup_on_stack(&t, rcu_torture_timer, 0); + tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. do { if (irqreader && cur_ops->irq_capable) { if (!timer_pending(&t)) mod_timer(&t, jiffies + 1); } - idx = cur_ops->readlock(); - if (cur_ops->started) - started = cur_ops->started(); - else - started = cur_ops->completed(); - ts = rcu_trace_clock_local(); - p = rcu_dereference_check(rcu_torture_current, - rcu_read_lock_bh_held() || - rcu_read_lock_sched_held() || - srcu_read_lock_held(srcu_ctlp) || - torturing_tasks()); - if (p == NULL) { - /* Wait for rcu_torture_writer to get underway */ - cur_ops->readunlock(idx); + if (!rcu_torture_one_read(&rand, myid) && !torture_must_stop()) schedule_timeout_interruptible(HZ); - continue; - } - if (p->rtort_mbtest == 0) - atomic_inc(&n_rcu_torture_mberror); - cur_ops->read_delay(&rand); - preempt_disable(); - pipe_count = p->rtort_pipe_count; - if (pipe_count > RCU_TORTURE_PIPE_LEN) { - /* Should not happen, but... */ - pipe_count = RCU_TORTURE_PIPE_LEN; - } - completed = cur_ops->completed(); - if (pipe_count > 1) { - do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, - ts, started, completed); - rcu_ftrace_dump(DUMP_ALL); + if (time_after(jiffies, lastsleep) && !torture_must_stop()) { + torture_hrtimeout_us(500, 1000, &rand); + lastsleep = jiffies + 10; } - __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = completed - started; - if (cur_ops->started) - completed++; - if (completed > RCU_TORTURE_PIPE_LEN) { - /* Should not happen, but... */ - completed = RCU_TORTURE_PIPE_LEN; - } - __this_cpu_inc(rcu_torture_batch[completed]); - preempt_enable(); - cur_ops->readunlock(idx); + while (!torture_must_stop() && + (torture_num_online_cpus() < mynumonline || !rcu_inkernel_boot_has_ended())) + schedule_timeout_interruptible(HZ / 5); stutter_wait("rcu_torture_reader"); } while (!torture_must_stop()); if (irqreader && cur_ops->irq_capable) { - del_timer_sync(&t); - destroy_timer_on_stack(&t); + timer_delete_sync(&t); + timer_destroy_on_stack(&t); } + tick_dep_clear_task(current, TICK_DEP_BIT_RCU); torture_kthread_stopping("rcu_torture_reader"); return 0; } +struct rcu_torture_one_read_state_updown { + struct hrtimer rtorsu_hrt; + bool rtorsu_inuse; + ktime_t rtorsu_kt; + int rtorsu_cpu; + unsigned long rtorsu_j; + unsigned long rtorsu_ndowns; + unsigned long rtorsu_nups; + unsigned long rtorsu_nmigrates; + struct torture_random_state rtorsu_trs; + struct rcu_torture_one_read_state rtorsu_rtors; +}; + +static struct rcu_torture_one_read_state_updown *updownreaders; +static DEFINE_TORTURE_RANDOM(rcu_torture_updown_rand); +static int rcu_torture_updown(void *arg); + +static enum hrtimer_restart rcu_torture_updown_hrt(struct hrtimer *hrtp) +{ + int cpu = raw_smp_processor_id(); + struct rcu_torture_one_read_state_updown *rtorsup; + + rtorsup = container_of(hrtp, struct rcu_torture_one_read_state_updown, rtorsu_hrt); + rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); + WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); + WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); + WRITE_ONCE(rtorsup->rtorsu_nmigrates, + rtorsup->rtorsu_nmigrates + (cpu != rtorsup->rtorsu_cpu)); + smp_store_release(&rtorsup->rtorsu_inuse, false); + return HRTIMER_NORESTART; +} + +static int rcu_torture_updown_init(void) +{ + int i; + struct torture_random_state *rand = &rcu_torture_updown_rand; + int ret; + + if (n_up_down < 0) + return 0; + if (!srcu_torture_have_up_down()) { + VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Disabling up/down reader tests due to lack of primitives"); + return 0; + } + updownreaders = kcalloc(n_up_down, sizeof(*updownreaders), GFP_KERNEL); + if (!updownreaders) { + VERBOSE_TOROUT_STRING("rcu_torture_updown_init: Out of memory, disabling up/down reader tests"); + return -ENOMEM; + } + for (i = 0; i < n_up_down; i++) { + init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, rand); + hrtimer_setup(&updownreaders[i].rtorsu_hrt, rcu_torture_updown_hrt, CLOCK_MONOTONIC, + HRTIMER_MODE_REL | HRTIMER_MODE_HARD); + torture_random_init(&updownreaders[i].rtorsu_trs); + init_rcu_torture_one_read_state(&updownreaders[i].rtorsu_rtors, + &updownreaders[i].rtorsu_trs); + } + ret = torture_create_kthread(rcu_torture_updown, rand, updown_task); + if (ret) { + kfree(updownreaders); + updownreaders = NULL; + } + return ret; +} + +static void rcu_torture_updown_cleanup(void) +{ + struct rcu_torture_one_read_state_updown *rtorsup; + + for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { + if (!smp_load_acquire(&rtorsup->rtorsu_inuse)) + continue; + if (hrtimer_cancel(&rtorsup->rtorsu_hrt) || WARN_ON_ONCE(rtorsup->rtorsu_inuse)) { + rcu_torture_one_read_end(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); + WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); + WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); + smp_store_release(&rtorsup->rtorsu_inuse, false); + } + + } + kfree(updownreaders); + updownreaders = NULL; +} + +// Do one reader for rcu_torture_updown(). +static void rcu_torture_updown_one(struct rcu_torture_one_read_state_updown *rtorsup) +{ + int idx; + int rawidx; + ktime_t t; + + init_rcu_torture_one_read_state(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs); + rawidx = cur_ops->down_read(); + WRITE_ONCE(rtorsup->rtorsu_ndowns, rtorsup->rtorsu_ndowns + 1); + idx = (rawidx << RCUTORTURE_RDR_SHIFT_1) & RCUTORTURE_RDR_MASK_1; + rtorsup->rtorsu_rtors.readstate = idx | RCUTORTURE_RDR_UPDOWN; + rtorsup->rtorsu_rtors.rtrsp++; + rtorsup->rtorsu_cpu = raw_smp_processor_id(); + if (!rcu_torture_one_read_start(&rtorsup->rtorsu_rtors, &rtorsup->rtorsu_trs, -1)) { + WARN_ONCE(rtorsup->rtorsu_nups >= rtorsup->rtorsu_ndowns, "%s: Up without matching down #%zu.\n", __func__, rtorsup - updownreaders); + WRITE_ONCE(rtorsup->rtorsu_nups, rtorsup->rtorsu_nups + 1); + schedule_timeout_idle(HZ); + return; + } + smp_store_release(&rtorsup->rtorsu_inuse, true); + t = torture_random(&rtorsup->rtorsu_trs) & 0xfffff; // One per million. + if (t < 10 * 1000) + t = 200 * 1000 * 1000; + hrtimer_start(&rtorsup->rtorsu_hrt, t, HRTIMER_MODE_REL | HRTIMER_MODE_HARD); + smp_mb(); // Sample jiffies after posting hrtimer. + rtorsup->rtorsu_j = jiffies; // Not used by hrtimer handler. + rtorsup->rtorsu_kt = t; +} + +/* + * RCU torture up/down reader kthread, starting RCU readers in kthread + * context and ending them in hrtimer handlers. Otherwise similar to + * rcu_torture_reader(). + */ +static int +rcu_torture_updown(void *arg) +{ + unsigned long j; + struct rcu_torture_one_read_state_updown *rtorsup; + + VERBOSE_TOROUT_STRING("rcu_torture_updown task started"); + do { + for (rtorsup = updownreaders; rtorsup < &updownreaders[n_up_down]; rtorsup++) { + if (torture_must_stop()) + break; + j = smp_load_acquire(&jiffies); // Time before ->rtorsu_inuse. + if (smp_load_acquire(&rtorsup->rtorsu_inuse)) { + WARN_ONCE(time_after(j, rtorsup->rtorsu_j + 1 + HZ * 10), + "hrtimer queued at jiffies %lu for %lld ns took %lu jiffies\n", rtorsup->rtorsu_j, rtorsup->rtorsu_kt, j - rtorsup->rtorsu_j); + continue; + } + rcu_torture_updown_one(rtorsup); + } + torture_hrtimeout_ms(1, 1000, &rcu_torture_updown_rand); + stutter_wait("rcu_torture_updown"); + } while (!torture_must_stop()); + rcu_torture_updown_cleanup(); + torture_kthread_stopping("rcu_torture_updown"); + return 0; +} + +/* + * Randomly Toggle CPUs' callback-offload state. This uses hrtimers to + * increase race probabilities and fuzzes the interval between toggling. + */ +static int rcu_nocb_toggle(void *arg) +{ + int cpu; + int maxcpu = -1; + int oldnice = task_nice(current); + long r; + DEFINE_TORTURE_RANDOM(rand); + ktime_t toggle_delay; + unsigned long toggle_fuzz; + ktime_t toggle_interval = ms_to_ktime(nocbs_toggle); + + VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started"); + while (!rcu_inkernel_boot_has_ended()) + schedule_timeout_interruptible(HZ / 10); + for_each_possible_cpu(cpu) + maxcpu = cpu; + WARN_ON(maxcpu < 0); + if (toggle_interval > ULONG_MAX) + toggle_fuzz = ULONG_MAX >> 3; + else + toggle_fuzz = toggle_interval >> 3; + if (toggle_fuzz <= 0) + toggle_fuzz = NSEC_PER_USEC; + do { + r = torture_random(&rand); + cpu = (r >> 1) % (maxcpu + 1); + if (r & 0x1) { + rcu_nocb_cpu_offload(cpu); + atomic_long_inc(&n_nocb_offload); + } else { + rcu_nocb_cpu_deoffload(cpu); + atomic_long_inc(&n_nocb_deoffload); + } + toggle_delay = torture_random(&rand) % toggle_fuzz + toggle_interval; + set_current_state(TASK_INTERRUPTIBLE); + schedule_hrtimeout(&toggle_delay, HRTIMER_MODE_REL); + if (stutter_wait("rcu_nocb_toggle")) + sched_set_normal(current, oldnice); + } while (!torture_must_stop()); + torture_kthread_stopping("rcu_nocb_toggle"); + return 0; +} + /* * Print torture statistics. Caller must ensure that there is only * one call to this function at a given time!!! This is normally @@ -1274,54 +2720,81 @@ rcu_torture_stats_print(void) int i; long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; + long n_gpwraps = 0; + unsigned long ndowns = 0; + unsigned long nunexpired = 0; + unsigned long nmigrates = 0; + unsigned long nups = 0; + struct rcu_torture *rtcp; static unsigned long rtcv_snap = ULONG_MAX; + static bool splatted; struct task_struct *wtp; for_each_possible_cpu(cpu) { for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { - pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; - batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; + pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); + batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); + } + if (cur_ops->get_gpwrap_count) + n_gpwraps += cur_ops->get_gpwrap_count(cpu); + } + if (updownreaders) { + for (i = 0; i < n_up_down; i++) { + ndowns += READ_ONCE(updownreaders[i].rtorsu_ndowns); + nups += READ_ONCE(updownreaders[i].rtorsu_nups); + nunexpired += READ_ONCE(updownreaders[i].rtorsu_inuse); + nmigrates += READ_ONCE(updownreaders[i].rtorsu_nmigrates); } } - for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { + for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) { if (pipesummary[i] != 0) break; - } + } // The value of variable "i" is used later, so don't clobber it! pr_alert("%s%s ", torture_type, TORTURE_FLAG); - pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", - rcu_torture_current, + rtcp = rcu_access_pointer(rcu_torture_current); + pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", + rtcp, + rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER", rcu_torture_current_version, list_empty(&rcu_torture_freelist), atomic_read(&n_rcu_torture_alloc), atomic_read(&n_rcu_torture_alloc_fail), atomic_read(&n_rcu_torture_free)); - pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ", + pr_cont("rtmbe: %d rtmbkf: %d/%d rtbe: %ld rtbke: %ld ", atomic_read(&n_rcu_torture_mberror), + atomic_read(&n_rcu_torture_mbchk_fail), atomic_read(&n_rcu_torture_mbchk_tries), n_rcu_torture_barrier_error, - n_rcu_torture_boost_ktrerror, - n_rcu_torture_boost_rterror); + n_rcu_torture_boost_ktrerror); pr_cont("rtbf: %ld rtb: %ld nt: %ld ", n_rcu_torture_boost_failure, n_rcu_torture_boosts, - n_rcu_torture_timers); + atomic_long_read(&n_rcu_torture_timers)); + if (updownreaders) + pr_cont("ndowns: %lu nups: %lu nhrt: %lu nmigrates: %lu ", ndowns, nups, nunexpired, nmigrates); torture_onoff_stats(); pr_cont("barrier: %ld/%ld:%ld ", - n_barrier_successes, - n_barrier_attempts, - n_rcu_torture_barrier_error); - pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods)); + data_race(n_barrier_successes), + data_race(n_barrier_attempts), + data_race(n_rcu_torture_barrier_error)); + pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic. + pr_cont("nocb-toggles: %ld:%ld ", + atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload)); + pr_cont("gpwraps: %ld\n", n_gpwraps); pr_alert("%s%s ", torture_type, TORTURE_FLAG); - if (atomic_read(&n_rcu_torture_mberror) != 0 || - n_rcu_torture_barrier_error != 0 || - n_rcu_torture_boost_ktrerror != 0 || - n_rcu_torture_boost_rterror != 0 || - n_rcu_torture_boost_failure != 0 || - i > 1) { + if (atomic_read(&n_rcu_torture_mberror) || + atomic_read(&n_rcu_torture_mbchk_fail) || + n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || + n_rcu_torture_boost_failure || i > 1) { pr_cont("%s", "!!! "); atomic_inc(&n_rcu_torture_error); - WARN_ON_ONCE(1); + WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); + WARN_ON_ONCE(atomic_read(&n_rcu_torture_mbchk_fail)); + WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() + WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread + WARN_ON_ONCE(n_rcu_torture_boost_failure); // boost failed (TIMER_SOFTIRQ RT prio?) + WARN_ON_ONCE(i > 1); // Too-short grace period } pr_cont("Reader Pipe: "); for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) @@ -1344,22 +2817,26 @@ rcu_torture_stats_print(void) if (cur_ops->stats) cur_ops->stats(); if (rtcv_snap == rcu_torture_current_version && - rcu_torture_current != NULL) { + rcu_access_pointer(rcu_torture_current) && + !rcu_stall_is_suppressed() && + rcu_inkernel_boot_has_ended()) { int __maybe_unused flags = 0; - unsigned long __maybe_unused gpnum = 0; - unsigned long __maybe_unused completed = 0; + unsigned long __maybe_unused gp_seq = 0; - rcutorture_get_gp_data(cur_ops->ttype, - &flags, &gpnum, &completed); - srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, - &flags, &gpnum, &completed); + if (cur_ops->get_gp_data) + cur_ops->get_gp_data(&flags, &gp_seq); wtp = READ_ONCE(writer_task); - pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n", + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", rcu_torture_writer_state_getname(), - rcu_torture_writer_state, - gpnum, completed, flags, - wtp == NULL ? ~0UL : wtp->state); - show_rcu_gp_kthreads(); + rcu_torture_writer_state, gp_seq, flags, + wtp == NULL ? ~0U : wtp->__state, + wtp == NULL ? -1 : (int)task_cpu(wtp)); + if (!splatted && wtp) { + sched_show_task(wtp); + splatted = true; + } + if (cur_ops->gp_kthread_dbg) + cur_ops->gp_kthread_dbg(); rcu_ftrace_dump(DUMP_ALL); } rtcv_snap = rcu_torture_current_version; @@ -1382,7 +2859,57 @@ rcu_torture_stats(void *arg) return 0; } -static inline void +/* Test mem_dump_obj() and friends. */ +static void rcu_torture_mem_dump_obj(void) +{ + struct rcu_head *rhp; + struct kmem_cache *kcp; + static int z; + + kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL); + if (WARN_ON_ONCE(!kcp)) + return; + rhp = kmem_cache_alloc(kcp, GFP_KERNEL); + if (WARN_ON_ONCE(!rhp)) { + kmem_cache_destroy(kcp); + return; + } + pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z); + pr_alert("mem_dump_obj(ZERO_SIZE_PTR):"); + mem_dump_obj(ZERO_SIZE_PTR); + pr_alert("mem_dump_obj(NULL):"); + mem_dump_obj(NULL); + pr_alert("mem_dump_obj(%px):", &rhp); + mem_dump_obj(&rhp); + pr_alert("mem_dump_obj(%px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(%px):", &rhp->func); + mem_dump_obj(&rhp->func); + pr_alert("mem_dump_obj(%px):", &z); + mem_dump_obj(&z); + kmem_cache_free(kcp, rhp); + kmem_cache_destroy(kcp); + rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); + if (WARN_ON_ONCE(!rhp)) + return; + pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); + pr_alert("mem_dump_obj(kmalloc %px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func); + mem_dump_obj(&rhp->func); + kfree(rhp); + rhp = vmalloc(4096); + if (WARN_ON_ONCE(!rhp)) + return; + pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); + pr_alert("mem_dump_obj(vmalloc %px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func); + mem_dump_obj(&rhp->func); + vfree(rhp); +} + +static void rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) { pr_alert("%s" TORTURE_FLAG @@ -1391,18 +2918,30 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) "shuffle_interval=%d stutter=%d irqreader=%d " "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " "test_boost=%d/%d test_boost_interval=%d " - "test_boost_duration=%d shutdown_secs=%d " - "stall_cpu=%d stall_cpu_holdoff=%d " + "test_boost_duration=%d test_boost_holdoff=%d shutdown_secs=%d " + "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " + "stall_cpu_block=%d stall_cpu_repeat=%d " "n_barrier_cbs=%d " - "onoff_interval=%d onoff_holdoff=%d\n", - torture_type, tag, nrealreaders, nfakewriters, + "onoff_interval=%d onoff_holdoff=%d " + "read_exit_delay=%d read_exit_burst=%d " + "reader_flavor=%x " + "nocbs_nthreads=%d nocbs_toggle=%d " + "test_nmis=%d " + "preempt_duration=%d preempt_interval=%d n_up_down=%d\n", + torture_type, tag, nrealreaders, nrealfakewriters, stat_interval, verbose, test_no_idle_hz, shuffle_interval, stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, test_boost, cur_ops->can_boost, - test_boost_interval, test_boost_duration, shutdown_secs, - stall_cpu, stall_cpu_holdoff, + test_boost_interval, test_boost_duration, test_boost_holdoff, shutdown_secs, + stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, + stall_cpu_block, stall_cpu_repeat, n_barrier_cbs, - onoff_interval, onoff_holdoff); + onoff_interval, onoff_holdoff, + read_exit_delay, read_exit_burst, + reader_flavor, + nocbs_nthreads, nocbs_toggle, + test_nmis, + preempt_duration, preempt_interval, n_up_down); } static int rcutorture_booster_cleanup(unsigned int cpu) @@ -1414,6 +2953,7 @@ static int rcutorture_booster_cleanup(unsigned int cpu) mutex_lock(&boost_mutex); t = boost_tasks[cpu]; boost_tasks[cpu] = NULL; + rcu_torture_enable_rt_throttle(); mutex_unlock(&boost_mutex); /* This must be outside of the mutex, otherwise deadlock! */ @@ -1428,12 +2968,33 @@ static int rcutorture_booster_init(unsigned int cpu) if (boost_tasks[cpu] != NULL) return 0; /* Already created, nothing more to do. */ + // Testing RCU priority boosting requires rcutorture do + // some serious abuse. Counter this by running ksoftirqd + // at higher priority. + if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) { + struct sched_param sp; + struct task_struct *t; + + t = per_cpu(ksoftirqd, cpu); + WARN_ON_ONCE(!t); + sp.sched_priority = 2; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); +#ifdef CONFIG_IRQ_FORCED_THREADING + if (force_irqthreads()) { + t = per_cpu(ktimerd, cpu); + WARN_ON_ONCE(!t); + sp.sched_priority = 2; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); + } +#endif + } + /* Don't allow time recalculation while creating a new task. */ mutex_lock(&boost_mutex); + rcu_torture_disable_rt_throttle(); VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); - boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, - cpu_to_node(cpu), - "rcu_torture_boost"); + boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL, + cpu, "rcu_torture_boost_%u"); if (IS_ERR(boost_tasks[cpu])) { retval = PTR_ERR(boost_tasks[cpu]); VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); @@ -1442,37 +3003,107 @@ static int rcutorture_booster_init(unsigned int cpu) mutex_unlock(&boost_mutex); return retval; } - kthread_bind(boost_tasks[cpu], cpu); - wake_up_process(boost_tasks[cpu]); mutex_unlock(&boost_mutex); return 0; } +static int rcu_torture_stall_nf(struct notifier_block *nb, unsigned long v, void *ptr) +{ + pr_info("%s: v=%lu, duration=%lu.\n", __func__, v, (unsigned long)ptr); + return NOTIFY_OK; +} + +static struct notifier_block rcu_torture_stall_block = { + .notifier_call = rcu_torture_stall_nf, +}; + /* * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then - * induces a CPU stall for the time specified by stall_cpu. + * induces a CPU stall for the time specified by stall_cpu. If a new + * stall test is added, stallsdone in rcu_torture_writer() must be adjusted. */ -static int rcu_torture_stall(void *args) +static void rcu_torture_stall_one(int rep, int irqsoff) { + int idx; unsigned long stop_at; - VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); if (stall_cpu_holdoff > 0) { VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); schedule_timeout_interruptible(stall_cpu_holdoff * HZ); VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); } - if (!kthread_should_stop()) { - stop_at = get_seconds() + stall_cpu; + if (!kthread_should_stop() && stall_gp_kthread > 0) { + VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall"); + rcu_gp_set_torture_wait(stall_gp_kthread * HZ); + for (idx = 0; idx < stall_gp_kthread + 2; idx++) { + if (kthread_should_stop()) + break; + schedule_timeout_uninterruptible(HZ); + } + } + if (!kthread_should_stop() && stall_cpu > 0) { + VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall"); + stop_at = ktime_get_seconds() + stall_cpu; /* RCU CPU stall is expected behavior in following code. */ - pr_alert("rcu_torture_stall start.\n"); - rcu_read_lock(); - preempt_disable(); - while (ULONG_CMP_LT(get_seconds(), stop_at)) - continue; /* Induce RCU CPU stall warning. */ - preempt_enable(); - rcu_read_unlock(); - pr_alert("rcu_torture_stall end.\n"); + idx = cur_ops->readlock(); + if (irqsoff) + local_irq_disable(); + else if (!stall_cpu_block) + preempt_disable(); + pr_alert("%s start stall episode %d on CPU %d.\n", + __func__, rep + 1, raw_smp_processor_id()); + while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at) && + !kthread_should_stop()) + if (stall_cpu_block) { +#ifdef CONFIG_PREEMPTION + preempt_schedule(); +#else + schedule_timeout_uninterruptible(HZ); +#endif + } else if (stall_no_softlockup) { + touch_softlockup_watchdog(); + } + if (irqsoff) + local_irq_enable(); + else if (!stall_cpu_block) + preempt_enable(); + cur_ops->readunlock(idx); + } +} + +/* + * CPU-stall kthread. Invokes rcu_torture_stall_one() once, and then as many + * additional times as specified by the stall_cpu_repeat module parameter. + * Note that stall_cpu_irqsoff is ignored on the second and subsequent + * stall. + */ +static int rcu_torture_stall(void *args) +{ + int i; + int repeat = stall_cpu_repeat; + int ret; + + VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); + if (repeat < 0) { + repeat = 0; + WARN_ON_ONCE(IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)); + } + if (rcu_cpu_stall_notifiers) { + ret = rcu_stall_chain_notifier_register(&rcu_torture_stall_block); + if (ret) + pr_info("%s: rcu_stall_chain_notifier_register() returned %d, %sexpected.\n", + __func__, ret, !IS_ENABLED(CONFIG_RCU_STALL_COMMON) ? "un" : ""); + } + for (i = 0; i <= repeat; i++) { + if (kthread_should_stop()) + break; + rcu_torture_stall_one(i, i == 0 ? stall_cpu_irqsoff : 0); + } + pr_alert("%s end.\n", __func__); + if (rcu_cpu_stall_notifiers && !ret) { + ret = rcu_stall_chain_notifier_unregister(&rcu_torture_stall_block); + if (ret) + pr_info("%s: rcu_stall_chain_notifier_unregister() returned %d.\n", __func__, ret); } torture_shutdown_absorb("rcu_torture_stall"); while (!kthread_should_stop()) @@ -1483,22 +3114,544 @@ static int rcu_torture_stall(void *args) /* Spawn CPU-stall kthread, if stall_cpu specified. */ static int __init rcu_torture_stall_init(void) { - if (stall_cpu <= 0) + if (stall_cpu <= 0 && stall_gp_kthread <= 0) return 0; return torture_create_kthread(rcu_torture_stall, NULL, stall_task); } +/* State structure for forward-progress self-propagating RCU callback. */ +struct fwd_cb_state { + struct rcu_head rh; + int stop; +}; + +/* + * Forward-progress self-propagating RCU callback function. Because + * callbacks run from softirq, this function is an implicit RCU read-side + * critical section. + */ +static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) +{ + struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); + + if (READ_ONCE(fcsp->stop)) { + WRITE_ONCE(fcsp->stop, 2); + return; + } + cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); +} + +/* State for continuous-flood RCU callbacks. */ +struct rcu_fwd_cb { + struct rcu_head rh; + struct rcu_fwd_cb *rfc_next; + struct rcu_fwd *rfc_rfp; + int rfc_gps; +}; + +#define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ +#define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ +#define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ +#define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ +#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) + +struct rcu_launder_hist { + long n_launders; + unsigned long launder_gp_seq; +}; + +struct rcu_fwd { + spinlock_t rcu_fwd_lock; + struct rcu_fwd_cb *rcu_fwd_cb_head; + struct rcu_fwd_cb **rcu_fwd_cb_tail; + long n_launders_cb; + unsigned long rcu_fwd_startat; + struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; + unsigned long rcu_launder_gp_seq_start; + int rcu_fwd_id; +}; + +static DEFINE_MUTEX(rcu_fwd_mutex); +static struct rcu_fwd *rcu_fwds; +static unsigned long rcu_fwd_seq; +static atomic_long_t rcu_fwd_max_cbs; +static bool rcu_fwd_emergency_stop; + +static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp) +{ + unsigned long gps; + unsigned long gps_old; + int i; + int j; + + for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--) + if (rfp->n_launders_hist[i].n_launders > 0) + break; + pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):", + __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat); + gps_old = rfp->rcu_launder_gp_seq_start; + for (j = 0; j <= i; j++) { + gps = rfp->n_launders_hist[j].launder_gp_seq; + pr_cont(" %ds/%d: %ld:%ld", + j + 1, FWD_CBS_HIST_DIV, + rfp->n_launders_hist[j].n_launders, + rcutorture_seq_diff(gps, gps_old)); + gps_old = gps; + } + pr_cont("\n"); +} + +/* Callback function for continuous-flood RCU callbacks. */ +static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) +{ + unsigned long flags; + int i; + struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); + struct rcu_fwd_cb **rfcpp; + struct rcu_fwd *rfp = rfcp->rfc_rfp; + + rfcp->rfc_next = NULL; + rfcp->rfc_gps++; + spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); + rfcpp = rfp->rcu_fwd_cb_tail; + rfp->rcu_fwd_cb_tail = &rfcp->rfc_next; + smp_store_release(rfcpp, rfcp); + WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1); + i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); + if (i >= ARRAY_SIZE(rfp->n_launders_hist)) + i = ARRAY_SIZE(rfp->n_launders_hist) - 1; + rfp->n_launders_hist[i].n_launders++; + rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); + spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); +} + +// Give the scheduler a chance, even on nohz_full CPUs. +static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) +{ + if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { + // Real call_rcu() floods hit userspace, so emulate that. + if (need_resched() || (iter & 0xfff)) + schedule(); + return; + } + // No userspace emulation: CB invocation throttles call_rcu() + cond_resched(); +} + +/* + * Free all callbacks on the rcu_fwd_cb_head list, either because the + * test is over or because we hit an OOM event. + */ +static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp) +{ + unsigned long flags; + unsigned long freed = 0; + struct rcu_fwd_cb *rfcp; + + for (;;) { + spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); + rfcp = rfp->rcu_fwd_cb_head; + if (!rfcp) { + spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); + break; + } + rfp->rcu_fwd_cb_head = rfcp->rfc_next; + if (!rfp->rcu_fwd_cb_head) + rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; + spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); + kfree(rfcp); + freed++; + rcu_torture_fwd_prog_cond_resched(freed); + if (tick_nohz_full_enabled()) { + local_irq_save(flags); + rcu_momentary_eqs(); + local_irq_restore(flags); + } + } + return freed; +} + +/* Carry out need_resched()/cond_resched() forward-progress testing. */ +static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, + int *tested, int *tested_tries) +{ + unsigned long cver; + unsigned long dur; + struct fwd_cb_state fcs; + unsigned long gps; + int idx; + int sd; + int sd4; + bool selfpropcb = false; + unsigned long stopat; + static DEFINE_TORTURE_RANDOM(trs); + + pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); + if (!cur_ops->sync) + return; // Cannot do need_resched() forward progress testing without ->sync. + if (cur_ops->call && cur_ops->cb_barrier) { + init_rcu_head_on_stack(&fcs.rh); + selfpropcb = true; + } + + /* Tight loop containing cond_resched(). */ + atomic_inc(&rcu_fwd_cb_nodelay); + cur_ops->sync(); /* Later readers see above write. */ + if (selfpropcb) { + WRITE_ONCE(fcs.stop, 0); + cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); + } + cver = READ_ONCE(rcu_torture_current_version); + gps = cur_ops->get_gp_seq(); + sd = cur_ops->stall_dur() + 1; + sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; + dur = sd4 + torture_random(&trs) % (sd - sd4); + WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); + stopat = rfp->rcu_fwd_startat + dur; + while (time_before(jiffies, stopat) && + !shutdown_time_arrived() && + !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { + idx = cur_ops->readlock(); + udelay(10); + cur_ops->readunlock(idx); + if (!fwd_progress_need_resched || need_resched()) + cond_resched(); + } + (*tested_tries)++; + if (!time_before(jiffies, stopat) && + !shutdown_time_arrived() && + !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { + (*tested)++; + cver = READ_ONCE(rcu_torture_current_version) - cver; + gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); + WARN_ON(!cver && gps < 2); + pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__, + rfp->rcu_fwd_id, dur, cver, gps); + } + if (selfpropcb) { + WRITE_ONCE(fcs.stop, 1); + cur_ops->sync(); /* Wait for running CB to complete. */ + pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); + cur_ops->cb_barrier(); /* Wait for queued callbacks. */ + } + + if (selfpropcb) { + WARN_ON(READ_ONCE(fcs.stop) != 2); + destroy_rcu_head_on_stack(&fcs.rh); + } + schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ + atomic_dec(&rcu_fwd_cb_nodelay); +} + +/* Carry out call_rcu() forward-progress testing. */ +static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) +{ + unsigned long cver; + unsigned long flags; + unsigned long gps; + int i; + long n_launders; + long n_launders_cb_snap; + long n_launders_sa; + long n_max_cbs; + long n_max_gps; + struct rcu_fwd_cb *rfcp; + struct rcu_fwd_cb *rfcpn; + unsigned long stopat; + unsigned long stoppedat; + + pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); + if (READ_ONCE(rcu_fwd_emergency_stop)) + return; /* Get out of the way quickly, no GP wait! */ + if (!cur_ops->call) + return; /* Can't do call_rcu() fwd prog without ->call. */ + + /* Loop continuously posting RCU callbacks. */ + atomic_inc(&rcu_fwd_cb_nodelay); + cur_ops->sync(); /* Later readers see above write. */ + WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); + stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES; + n_launders = 0; + rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread + n_launders_sa = 0; + n_max_cbs = 0; + n_max_gps = 0; + for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++) + rfp->n_launders_hist[i].n_launders = 0; + cver = READ_ONCE(rcu_torture_current_version); + gps = cur_ops->get_gp_seq(); + rfp->rcu_launder_gp_seq_start = gps; + tick_dep_set_task(current, TICK_DEP_BIT_RCU); // CPU bound, so need tick. + while (time_before(jiffies, stopat) && + !shutdown_time_arrived() && + !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { + rfcp = READ_ONCE(rfp->rcu_fwd_cb_head); + rfcpn = NULL; + if (rfcp) + rfcpn = READ_ONCE(rfcp->rfc_next); + if (rfcpn) { + if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && + ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) + break; + rfp->rcu_fwd_cb_head = rfcpn; + n_launders++; + n_launders_sa++; + } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) { + rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); + if (WARN_ON_ONCE(!rfcp)) { + schedule_timeout_interruptible(1); + continue; + } + n_max_cbs++; + n_launders_sa = 0; + rfcp->rfc_gps = 0; + rfcp->rfc_rfp = rfp; + } else { + rfcp = NULL; + } + if (rfcp) + cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); + rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); + if (tick_nohz_full_enabled()) { + local_irq_save(flags); + rcu_momentary_eqs(); + local_irq_restore(flags); + } + } + stoppedat = jiffies; + n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); + cver = READ_ONCE(rcu_torture_current_version) - cver; + gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); + pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); + cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ + (void)rcu_torture_fwd_prog_cbfree(rfp); + + if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && + !shutdown_time_arrived()) { + if (WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED) && cur_ops->gp_kthread_dbg) + cur_ops->gp_kthread_dbg(); + pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld #online %u\n", + __func__, + stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat, + n_launders + n_max_cbs - n_launders_cb_snap, + n_launders, n_launders_sa, + n_max_gps, n_max_cbs, cver, gps, num_online_cpus()); + atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs); + mutex_lock(&rcu_fwd_mutex); // Serialize histograms. + rcu_torture_fwd_cb_hist(rfp); + mutex_unlock(&rcu_fwd_mutex); + } + schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ + tick_dep_clear_task(current, TICK_DEP_BIT_RCU); + atomic_dec(&rcu_fwd_cb_nodelay); +} + + +/* + * OOM notifier, but this only prints diagnostic information for the + * current forward-progress test. + */ +static int rcutorture_oom_notify(struct notifier_block *self, + unsigned long notused, void *nfreed) +{ + int i; + long ncbs; + struct rcu_fwd *rfp; + + mutex_lock(&rcu_fwd_mutex); + rfp = rcu_fwds; + if (!rfp) { + mutex_unlock(&rcu_fwd_mutex); + return NOTIFY_OK; + } + WARN(1, "%s invoked upon OOM during forward-progress testing.\n", + __func__); + for (i = 0; i < fwd_progress; i++) { + rcu_torture_fwd_cb_hist(&rfp[i]); + rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2); + } + WRITE_ONCE(rcu_fwd_emergency_stop, true); + smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ + ncbs = 0; + for (i = 0; i < fwd_progress; i++) + ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); + pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); + cur_ops->cb_barrier(); + ncbs = 0; + for (i = 0; i < fwd_progress; i++) + ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); + pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); + cur_ops->cb_barrier(); + ncbs = 0; + for (i = 0; i < fwd_progress; i++) + ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]); + pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs); + smp_mb(); /* Frees before return to avoid redoing OOM. */ + (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ + pr_info("%s returning after OOM processing.\n", __func__); + mutex_unlock(&rcu_fwd_mutex); + return NOTIFY_OK; +} + +static struct notifier_block rcutorture_oom_nb = { + .notifier_call = rcutorture_oom_notify +}; + +/* Carry out grace-period forward-progress testing. */ +static int rcu_torture_fwd_prog(void *args) +{ + bool firsttime = true; + long max_cbs; + int oldnice = task_nice(current); + unsigned long oldseq = READ_ONCE(rcu_fwd_seq); + struct rcu_fwd *rfp = args; + int tested = 0; + int tested_tries = 0; + + VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); + while (!rcu_inkernel_boot_has_ended()) + schedule_timeout_interruptible(HZ / 10); + rcu_bind_current_to_nocb(); + if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) + set_user_nice(current, MAX_NICE); + do { + if (!rfp->rcu_fwd_id) { + schedule_timeout_interruptible(fwd_progress_holdoff * HZ); + WRITE_ONCE(rcu_fwd_emergency_stop, false); + if (!firsttime) { + max_cbs = atomic_long_xchg(&rcu_fwd_max_cbs, 0); + pr_alert("%s n_max_cbs: %ld\n", __func__, max_cbs); + } + firsttime = false; + WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1); + } else { + while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop()) + schedule_timeout_interruptible(HZ / 20); + oldseq = READ_ONCE(rcu_fwd_seq); + } + pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); + if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id) + rcu_torture_fwd_prog_cr(rfp); + if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) && + (!IS_ENABLED(CONFIG_TINY_RCU) || + (rcu_inkernel_boot_has_ended() && + torture_num_online_cpus() > rfp->rcu_fwd_id))) + rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); + + /* Avoid slow periods, better to test when busy. */ + if (stutter_wait("rcu_torture_fwd_prog")) + sched_set_normal(current, oldnice); + } while (!torture_must_stop()); + /* Short runs might not contain a valid forward-progress attempt. */ + if (!rfp->rcu_fwd_id) { + WARN_ON(!tested && tested_tries >= 5); + pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); + } + torture_kthread_stopping("rcu_torture_fwd_prog"); + return 0; +} + +/* If forward-progress checking is requested and feasible, spawn the thread. */ +static int __init rcu_torture_fwd_prog_init(void) +{ + int i; + int ret = 0; + struct rcu_fwd *rfp; + + if (!fwd_progress) + return 0; /* Not requested, so don't do it. */ + if (fwd_progress >= nr_cpu_ids) { + VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n"); + fwd_progress = nr_cpu_ids; + } else if (fwd_progress < 0) { + fwd_progress = nr_cpu_ids; + } + if ((!cur_ops->sync && !cur_ops->call) || + (!cur_ops->cbflood_max && (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0)) || + cur_ops == &rcu_busted_ops) { + VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); + fwd_progress = 0; + return 0; + } + if (stall_cpu > 0 || (preempt_duration > 0 && IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { + VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall and/or preemption testing"); + fwd_progress = 0; + if (IS_MODULE(CONFIG_RCU_TORTURE_TEST)) + return -EINVAL; /* In module, can fail back to user. */ + WARN_ON(1); /* Make sure rcutorture scripting notices conflict. */ + return 0; + } + if (fwd_progress_holdoff <= 0) + fwd_progress_holdoff = 1; + if (fwd_progress_div <= 0) + fwd_progress_div = 4; + rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL); + fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL); + if (!rfp || !fwd_prog_tasks) { + kfree(rfp); + kfree(fwd_prog_tasks); + fwd_prog_tasks = NULL; + fwd_progress = 0; + return -ENOMEM; + } + for (i = 0; i < fwd_progress; i++) { + spin_lock_init(&rfp[i].rcu_fwd_lock); + rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head; + rfp[i].rcu_fwd_id = i; + } + mutex_lock(&rcu_fwd_mutex); + rcu_fwds = rfp; + mutex_unlock(&rcu_fwd_mutex); + register_oom_notifier(&rcutorture_oom_nb); + for (i = 0; i < fwd_progress; i++) { + ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]); + if (ret) { + fwd_progress = i; + return ret; + } + } + return 0; +} + +static void rcu_torture_fwd_prog_cleanup(void) +{ + int i; + struct rcu_fwd *rfp; + + if (!rcu_fwds || !fwd_prog_tasks) + return; + for (i = 0; i < fwd_progress; i++) + torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]); + unregister_oom_notifier(&rcutorture_oom_nb); + mutex_lock(&rcu_fwd_mutex); + rfp = rcu_fwds; + rcu_fwds = NULL; + mutex_unlock(&rcu_fwd_mutex); + kfree(rfp); + kfree(fwd_prog_tasks); + fwd_prog_tasks = NULL; +} + /* Callback function for RCU barrier testing. */ static void rcu_torture_barrier_cbf(struct rcu_head *rcu) { atomic_inc(&barrier_cbs_invoked); } +/* IPI handler to get callback posted on desired CPU, if online. */ +static int rcu_torture_barrier1cb(void *rcu_void) +{ + struct rcu_head *rhp = rcu_void; + + cur_ops->call(rhp, rcu_torture_barrier_cbf); + return 0; +} + /* kthread function to register callbacks used to test RCU barriers. */ static int rcu_torture_barrier_cbs(void *arg) { long myid = (long)arg; - bool lastphase = 0; + bool lastphase = false; bool newphase; struct rcu_head rcu; @@ -1517,9 +3670,9 @@ static int rcu_torture_barrier_cbs(void *arg) * The above smp_load_acquire() ensures barrier_phase load * is ordered before the following ->call(). */ - local_irq_disable(); /* Just to test no-irq call_rcu(). */ - cur_ops->call(&rcu, rcu_torture_barrier_cbf); - local_irq_enable(); + if (smp_call_on_cpu(myid, rcu_torture_barrier1cb, &rcu, 1)) + cur_ops->call(&rcu, rcu_torture_barrier_cbf); + if (atomic_dec_and_test(&barrier_cbs_count)) wake_up(&barrier_wq); } while (!torture_must_stop()); @@ -1555,9 +3708,24 @@ static int rcu_torture_barrier(void *arg) pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", atomic_read(&barrier_cbs_invoked), n_barrier_cbs); - WARN_ON_ONCE(1); + WARN_ON(1); + // Wait manually for the remaining callbacks + i = 0; + do { + if (WARN_ON(i++ > HZ)) + i = INT_MIN; + schedule_timeout_interruptible(1); + cur_ops->cb_barrier(); + } while (atomic_read(&barrier_cbs_invoked) != + n_barrier_cbs && + !torture_must_stop()); + smp_mb(); // Can't trust ordering if broken. + if (!torture_must_stop()) + pr_err("Recovered: barrier_cbs_invoked = %d\n", + atomic_read(&barrier_cbs_invoked)); + } else { + n_barrier_successes++; } - n_barrier_successes++; schedule_timeout_interruptible(HZ / 10); } while (!torture_must_stop()); torture_kthread_stopping("rcu_torture_barrier"); @@ -1584,11 +3752,10 @@ static int rcu_torture_barrier_init(void) atomic_set(&barrier_cbs_count, 0); atomic_set(&barrier_cbs_invoked, 0); barrier_cbs_tasks = - kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]), + kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]), GFP_KERNEL); barrier_cbs_wq = - kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]), - GFP_KERNEL); + kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL); if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) return -ENOMEM; for (i = 0; i < n_barrier_cbs; i++) { @@ -1621,60 +3788,386 @@ static void rcu_torture_barrier_cleanup(void) } } +static bool rcu_torture_can_boost(void) +{ + static int boost_warn_once; + int prio; + + if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) + return false; + if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state) + return false; + + prio = rcu_get_gp_kthreads_prio(); + if (!prio) + return false; + + if (prio < 2) { + if (boost_warn_once == 1) + return false; + + pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME); + boost_warn_once = 1; + return false; + } + + return true; +} + +static bool read_exit_child_stop; +static bool read_exit_child_stopped; +static wait_queue_head_t read_exit_wq; + +// Child kthread which just does an rcutorture reader and exits. +static int rcu_torture_read_exit_child(void *trsp_in) +{ + struct torture_random_state *trsp = trsp_in; + + set_user_nice(current, MAX_NICE); + // Minimize time between reading and exiting. + while (!kthread_should_stop()) + schedule_timeout_uninterruptible(HZ / 20); + (void)rcu_torture_one_read(trsp, -1); + return 0; +} + +// Parent kthread which creates and destroys read-exit child kthreads. +static int rcu_torture_read_exit(void *unused) +{ + bool errexit = false; + int i; + struct task_struct *tsp; + DEFINE_TORTURE_RANDOM(trs); + + // Allocate and initialize. + set_user_nice(current, MAX_NICE); + VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test"); + + // Each pass through this loop does one read-exit episode. + do { + VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode"); + for (i = 0; i < read_exit_burst; i++) { + if (READ_ONCE(read_exit_child_stop)) + break; + stutter_wait("rcu_torture_read_exit"); + // Spawn child. + tsp = kthread_run(rcu_torture_read_exit_child, + &trs, "%s", "rcu_torture_read_exit_child"); + if (IS_ERR(tsp)) { + TOROUT_ERRSTRING("out of memory"); + errexit = true; + break; + } + cond_resched(); + kthread_stop(tsp); + n_read_exits++; + } + VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode"); + rcu_barrier(); // Wait for task_struct free, avoid OOM. + i = 0; + for (; !errexit && !READ_ONCE(read_exit_child_stop) && i < read_exit_delay; i++) + schedule_timeout_uninterruptible(HZ); + } while (!errexit && !READ_ONCE(read_exit_child_stop)); + + // Clean up and exit. + smp_store_release(&read_exit_child_stopped, true); // After reaping. + smp_mb(); // Store before wakeup. + wake_up(&read_exit_wq); + while (!torture_must_stop()) + schedule_timeout_uninterruptible(HZ / 20); + torture_kthread_stopping("rcu_torture_read_exit"); + return 0; +} + +static int rcu_torture_read_exit_init(void) +{ + if (read_exit_burst <= 0) + return 0; + init_waitqueue_head(&read_exit_wq); + read_exit_child_stop = false; + read_exit_child_stopped = false; + return torture_create_kthread(rcu_torture_read_exit, NULL, + read_exit_task); +} + +static void rcu_torture_read_exit_cleanup(void) +{ + if (!read_exit_task) + return; + WRITE_ONCE(read_exit_child_stop, true); + smp_mb(); // Above write before wait. + wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped)); + torture_stop_kthread(rcutorture_read_exit, read_exit_task); +} + +static void rcutorture_test_nmis(int n) +{ +#if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) + int cpu; + int dumpcpu; + int i; + + for (i = 0; i < n; i++) { + preempt_disable(); + cpu = smp_processor_id(); + dumpcpu = cpu + 1; + if (dumpcpu >= nr_cpu_ids) + dumpcpu = 0; + pr_alert("%s: CPU %d invoking dump_cpu_task(%d)\n", __func__, cpu, dumpcpu); + dump_cpu_task(dumpcpu); + preempt_enable(); + schedule_timeout_uninterruptible(15 * HZ); + } +#else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) + WARN_ONCE(n, "Non-zero rcutorture.test_nmis=%d permitted only when rcutorture is built in.\n", test_nmis); +#endif // #else // #if IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) +} + +// Randomly preempt online CPUs. +static int rcu_torture_preempt(void *unused) +{ + int cpu = -1; + DEFINE_TORTURE_RANDOM(rand); + + schedule_timeout_idle(stall_cpu_holdoff); + do { + // Wait for preempt_interval ms with up to 100us fuzz. + torture_hrtimeout_ms(preempt_interval, 100, &rand); + // Select online CPU. + cpu = cpumask_next(cpu, cpu_online_mask); + if (cpu >= nr_cpu_ids) + cpu = cpumask_next(-1, cpu_online_mask); + WARN_ON_ONCE(cpu >= nr_cpu_ids); + // Move to that CPU, if can't do so, retry later. + if (torture_sched_setaffinity(current->pid, cpumask_of(cpu), false)) + continue; + // Preempt at high-ish priority, then reset to normal. + sched_set_fifo(current); + torture_sched_setaffinity(current->pid, cpu_present_mask, true); + mdelay(preempt_duration); + sched_set_normal(current, 0); + stutter_wait("rcu_torture_preempt"); + } while (!torture_must_stop()); + torture_kthread_stopping("rcu_torture_preempt"); + return 0; +} + static enum cpuhp_state rcutor_hp; +static struct hrtimer gpwrap_lag_timer; +static bool gpwrap_lag_active; + +/* Timer handler for toggling RCU grace-period sequence overflow test lag value */ +static enum hrtimer_restart rcu_gpwrap_lag_timer(struct hrtimer *timer) +{ + ktime_t next_delay; + + if (gpwrap_lag_active) { + pr_alert("rcu-torture: Disabling gpwrap lag (value=0)\n"); + cur_ops->set_gpwrap_lag(0); + gpwrap_lag_active = false; + next_delay = ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0); + } else { + pr_alert("rcu-torture: Enabling gpwrap lag (value=%d)\n", gpwrap_lag_gps); + cur_ops->set_gpwrap_lag(gpwrap_lag_gps); + gpwrap_lag_active = true; + next_delay = ktime_set(gpwrap_lag_active_mins * 60, 0); + } + + if (torture_must_stop_irq()) + return HRTIMER_NORESTART; + + hrtimer_forward_now(timer, next_delay); + return HRTIMER_RESTART; +} + +static int rcu_gpwrap_lag_init(void) +{ + if (!gpwrap_lag) + return 0; + + if (gpwrap_lag_cycle_mins <= 0 || gpwrap_lag_active_mins <= 0) { + pr_alert("rcu-torture: lag timing parameters must be positive\n"); + return -EINVAL; + } + + hrtimer_setup(&gpwrap_lag_timer, rcu_gpwrap_lag_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + gpwrap_lag_active = false; + hrtimer_start(&gpwrap_lag_timer, + ktime_set((gpwrap_lag_cycle_mins - gpwrap_lag_active_mins) * 60, 0), HRTIMER_MODE_REL); + + return 0; +} + +static void rcu_gpwrap_lag_cleanup(void) +{ + hrtimer_cancel(&gpwrap_lag_timer); + cur_ops->set_gpwrap_lag(0); + gpwrap_lag_active = false; +} static void rcu_torture_cleanup(void) { + int firsttime; + int flags = 0; + unsigned long gp_seq = 0; int i; + int j; - rcutorture_record_test_transition(); if (torture_cleanup_begin()) { - if (cur_ops->cb_barrier != NULL) + if (cur_ops->cb_barrier != NULL) { + pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); cur_ops->cb_barrier(); + } + if (cur_ops->gp_slow_unregister) + cur_ops->gp_slow_unregister(NULL); + return; + } + if (!cur_ops) { + torture_cleanup_end(); return; } + rcutorture_test_nmis(test_nmis); + + if (cur_ops->gp_kthread_dbg) + cur_ops->gp_kthread_dbg(); + torture_stop_kthread(rcu_torture_preempt, preempt_task); + rcu_torture_read_exit_cleanup(); rcu_torture_barrier_cleanup(); + rcu_torture_fwd_prog_cleanup(); torture_stop_kthread(rcu_torture_stall, stall_task); torture_stop_kthread(rcu_torture_writer, writer_task); + if (nocb_tasks) { + for (i = 0; i < nrealnocbers; i++) + torture_stop_kthread(rcu_nocb_toggle, nocb_tasks[i]); + kfree(nocb_tasks); + nocb_tasks = NULL; + } + + if (updown_task) { + torture_stop_kthread(rcu_torture_updown, updown_task); + updown_task = NULL; + } if (reader_tasks) { for (i = 0; i < nrealreaders; i++) torture_stop_kthread(rcu_torture_reader, reader_tasks[i]); kfree(reader_tasks); + reader_tasks = NULL; } - rcu_torture_current = NULL; + kfree(rcu_torture_reader_mbchk); + rcu_torture_reader_mbchk = NULL; if (fakewriter_tasks) { - for (i = 0; i < nfakewriters; i++) { + for (i = 0; i < nrealfakewriters; i++) torture_stop_kthread(rcu_torture_fakewriter, fakewriter_tasks[i]); - } kfree(fakewriter_tasks); fakewriter_tasks = NULL; } + if (cur_ops->get_gp_data) + cur_ops->get_gp_data(&flags, &gp_seq); + pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n", + cur_ops->name, (long)gp_seq, flags, + rcutorture_seq_diff(gp_seq, start_gp_seq)); torture_stop_kthread(rcu_torture_stats, stats_task); torture_stop_kthread(rcu_torture_fqs, fqs_task); - for (i = 0; i < ncbflooders; i++) - torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]); - if ((test_boost == 1 && cur_ops->can_boost) || - test_boost == 2) + if (rcu_torture_can_boost() && rcutor_hp >= 0) cpuhp_remove_state(rcutor_hp); /* - * Wait for all RCU callbacks to fire, then do flavor-specific + * Wait for all RCU callbacks to fire, then do torture-type-specific * cleanup operations. */ - if (cur_ops->cb_barrier != NULL) + if (cur_ops->cb_barrier != NULL) { + pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier); cur_ops->cb_barrier(); + } if (cur_ops->cleanup != NULL) cur_ops->cleanup(); + rcu_torture_mem_dump_obj(); + rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ + if (err_segs_recorded) { + pr_alert("Failure/close-call rcutorture reader segments:\n"); + if (rt_read_nsegs == 0) + pr_alert("\t: No segments recorded!!!\n"); + firsttime = 1; + for (i = 0; i < rt_read_nsegs; i++) { + if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP)) + pr_alert("\t%lluus ", div64_u64(err_segs[i].rt_ts, 1000ULL)); + else + pr_alert("\t"); + pr_cont("%d: %#4x", i, err_segs[i].rt_readstate); + if (err_segs[i].rt_delay_jiffies != 0) { + pr_cont("%s%ldjiffies", firsttime ? "" : "+", + err_segs[i].rt_delay_jiffies); + firsttime = 0; + } + if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_CPU)) { + pr_cont(" CPU %2d", err_segs[i].rt_cpu); + if (err_segs[i].rt_cpu != err_segs[i].rt_end_cpu) + pr_cont("->%-2d", err_segs[i].rt_end_cpu); + else + pr_cont(" ..."); + } + if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_LOG_GP) && + cur_ops->gather_gp_seqs && cur_ops->format_gp_seqs) { + char buf1[20+1]; + char buf2[20+1]; + char sepchar = '-'; + + cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq, + buf1, ARRAY_SIZE(buf1)); + cur_ops->format_gp_seqs(err_segs[i].rt_gp_seq_end, + buf2, ARRAY_SIZE(buf2)); + if (err_segs[i].rt_gp_seq == err_segs[i].rt_gp_seq_end) { + if (buf2[0]) { + for (j = 0; buf2[j]; j++) + buf2[j] = '.'; + if (j) + buf2[j - 1] = ' '; + } + sepchar = ' '; + } + pr_cont(" %s%c%s", buf1, sepchar, buf2); + } + if (err_segs[i].rt_delay_ms != 0) { + pr_cont(" %s%ldms", firsttime ? "" : "+", + err_segs[i].rt_delay_ms); + firsttime = 0; + } + if (err_segs[i].rt_delay_us != 0) { + pr_cont(" %s%ldus", firsttime ? "" : "+", + err_segs[i].rt_delay_us); + firsttime = 0; + } + pr_cont("%s", err_segs[i].rt_preempted ? " preempted" : ""); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_BH) + pr_cont(" BH"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_IRQ) + pr_cont(" IRQ"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_PREEMPT) + pr_cont(" PREEMPT"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RBH) + pr_cont(" RBH"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_SCHED) + pr_cont(" SCHED"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_1) + pr_cont(" RCU_1"); + if (err_segs[i].rt_readstate & RCUTORTURE_RDR_RCU_2) + pr_cont(" RCU_2"); + pr_cont("\n"); + + } + if (rt_read_preempted) + pr_alert("\tReader was preempted.\n"); + } if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); else if (torture_onoff_failures()) @@ -1683,9 +4176,13 @@ rcu_torture_cleanup(void) else rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); torture_cleanup_end(); + if (cur_ops->gp_slow_unregister) + cur_ops->gp_slow_unregister(NULL); + + if (gpwrap_lag && cur_ops->set_gpwrap_lag) + rcu_gpwrap_lag_cleanup(); } -#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD static void rcu_torture_leak_cb(struct rcu_head *rhp) { } @@ -1701,9 +4198,8 @@ static void rcu_torture_err_cb(struct rcu_head *rhp) * next grace period. Unlikely, but can happen. If it * does happen, the debug-objects subsystem won't have splatted. */ - pr_alert("rcutorture: duplicated callback was invoked.\n"); + pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME); } -#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ /* * Verify that double-free causes debug-objects to complain, but only @@ -1712,47 +4208,250 @@ static void rcu_torture_err_cb(struct rcu_head *rhp) */ static void rcu_test_debug_objects(void) { -#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD struct rcu_head rh1; struct rcu_head rh2; + int idx; + + if (!IS_ENABLED(CONFIG_DEBUG_OBJECTS_RCU_HEAD)) { + pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_%s()\n", + KBUILD_MODNAME, cur_ops->name); + return; + } + + if (WARN_ON_ONCE(cur_ops->debug_objects && + (!cur_ops->call || !cur_ops->cb_barrier))) + return; + + struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); init_rcu_head_on_stack(&rh1); init_rcu_head_on_stack(&rh2); - pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n"); + pr_alert("%s: WARN: Duplicate call_%s() test starting.\n", KBUILD_MODNAME, cur_ops->name); /* Try to queue the rh2 pair of callbacks for the same grace period. */ - preempt_disable(); /* Prevent preemption from interrupting test. */ - rcu_read_lock(); /* Make it impossible to finish a grace period. */ - call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ - local_irq_disable(); /* Make it harder to start a new grace period. */ - call_rcu(&rh2, rcu_torture_leak_cb); - call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ - local_irq_enable(); - rcu_read_unlock(); - preempt_enable(); + idx = cur_ops->readlock(); /* Make it impossible to finish a grace period. */ + cur_ops->call(&rh1, rcu_torture_leak_cb); /* Start grace period. */ + cur_ops->call(&rh2, rcu_torture_leak_cb); + cur_ops->call(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ + if (rhp) { + cur_ops->call(rhp, rcu_torture_leak_cb); + cur_ops->call(rhp, rcu_torture_err_cb); /* Another duplicate callback. */ + } + cur_ops->readunlock(idx); /* Wait for them all to get done so we can safely return. */ - rcu_barrier(); - pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n"); + cur_ops->cb_barrier(); + pr_alert("%s: WARN: Duplicate call_%s() test complete.\n", KBUILD_MODNAME, cur_ops->name); destroy_rcu_head_on_stack(&rh1); destroy_rcu_head_on_stack(&rh2); -#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ - pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n"); -#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ + kfree(rhp); +} + +static void rcutorture_sync(void) +{ + static unsigned long n; + + if (cur_ops->sync && !(++n & 0xfff)) + cur_ops->sync(); +} + +static DEFINE_MUTEX(mut0); +static DEFINE_MUTEX(mut1); +static DEFINE_MUTEX(mut2); +static DEFINE_MUTEX(mut3); +static DEFINE_MUTEX(mut4); +static DEFINE_MUTEX(mut5); +static DEFINE_MUTEX(mut6); +static DEFINE_MUTEX(mut7); +static DEFINE_MUTEX(mut8); +static DEFINE_MUTEX(mut9); + +static DECLARE_RWSEM(rwsem0); +static DECLARE_RWSEM(rwsem1); +static DECLARE_RWSEM(rwsem2); +static DECLARE_RWSEM(rwsem3); +static DECLARE_RWSEM(rwsem4); +static DECLARE_RWSEM(rwsem5); +static DECLARE_RWSEM(rwsem6); +static DECLARE_RWSEM(rwsem7); +static DECLARE_RWSEM(rwsem8); +static DECLARE_RWSEM(rwsem9); + +DEFINE_STATIC_SRCU(srcu0); +DEFINE_STATIC_SRCU(srcu1); +DEFINE_STATIC_SRCU(srcu2); +DEFINE_STATIC_SRCU(srcu3); +DEFINE_STATIC_SRCU(srcu4); +DEFINE_STATIC_SRCU(srcu5); +DEFINE_STATIC_SRCU(srcu6); +DEFINE_STATIC_SRCU(srcu7); +DEFINE_STATIC_SRCU(srcu8); +DEFINE_STATIC_SRCU(srcu9); + +static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, const char *fu, int i, + int cyclelen, int deadlock) +{ + int j = i + 1; + + if (j >= cyclelen) + j = deadlock ? 0 : -1; + if (j >= 0) + pr_info("%s: %s(%d), %s(%d), %s(%d)\n", f, fl, i, fs, j, fu, i); + else + pr_info("%s: %s(%d), %s(%d)\n", f, fl, i, fu, i); + return j; +} + +// Test lockdep on SRCU-based deadlock scenarios. +static void rcu_torture_init_srcu_lockdep(void) +{ + int cyclelen; + int deadlock; + bool err = false; + int i; + int j; + int idx; + struct mutex *muts[] = { &mut0, &mut1, &mut2, &mut3, &mut4, + &mut5, &mut6, &mut7, &mut8, &mut9 }; + struct rw_semaphore *rwsems[] = { &rwsem0, &rwsem1, &rwsem2, &rwsem3, &rwsem4, + &rwsem5, &rwsem6, &rwsem7, &rwsem8, &rwsem9 }; + struct srcu_struct *srcus[] = { &srcu0, &srcu1, &srcu2, &srcu3, &srcu4, + &srcu5, &srcu6, &srcu7, &srcu8, &srcu9 }; + int testtype; + + if (!test_srcu_lockdep) + return; + + deadlock = test_srcu_lockdep / 1000; + testtype = (test_srcu_lockdep / 10) % 100; + cyclelen = test_srcu_lockdep % 10; + WARN_ON_ONCE(ARRAY_SIZE(muts) != ARRAY_SIZE(srcus)); + if (WARN_ONCE(deadlock != !!deadlock, + "%s: test_srcu_lockdep=%d and deadlock digit %d must be zero or one.\n", + __func__, test_srcu_lockdep, deadlock)) + err = true; + if (WARN_ONCE(cyclelen <= 0, + "%s: test_srcu_lockdep=%d and cycle-length digit %d must be greater than zero.\n", + __func__, test_srcu_lockdep, cyclelen)) + err = true; + if (err) + goto err_out; + + if (testtype == 0) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + if (deadlock && cyclelen == 1) + pr_info("%s: Expect hang.\n", __func__); + for (i = 0; i < cyclelen; i++) { + j = srcu_lockdep_next(__func__, "srcu_read_lock", "synchronize_srcu", + "srcu_read_unlock", i, cyclelen, deadlock); + idx = srcu_read_lock(srcus[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + srcu_read_unlock(srcus[i], idx); + } + return; + } + + if (testtype == 1) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU/mutex %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + for (i = 0; i < cyclelen; i++) { + pr_info("%s: srcu_read_lock(%d), mutex_lock(%d), mutex_unlock(%d), srcu_read_unlock(%d)\n", + __func__, i, i, i, i); + idx = srcu_read_lock(srcus[i]); + mutex_lock(muts[i]); + mutex_unlock(muts[i]); + srcu_read_unlock(srcus[i], idx); + + j = srcu_lockdep_next(__func__, "mutex_lock", "synchronize_srcu", + "mutex_unlock", i, cyclelen, deadlock); + mutex_lock(muts[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + mutex_unlock(muts[i]); + } + return; + } + + if (testtype == 2) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU/rwsem %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + for (i = 0; i < cyclelen; i++) { + pr_info("%s: srcu_read_lock(%d), down_read(%d), up_read(%d), srcu_read_unlock(%d)\n", + __func__, i, i, i, i); + idx = srcu_read_lock(srcus[i]); + down_read(rwsems[i]); + up_read(rwsems[i]); + srcu_read_unlock(srcus[i], idx); + + j = srcu_lockdep_next(__func__, "down_write", "synchronize_srcu", + "up_write", i, cyclelen, deadlock); + down_write(rwsems[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + up_write(rwsems[i]); + } + return; + } + +#ifdef CONFIG_TASKS_TRACE_RCU + if (testtype == 3) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU and Tasks Trace RCU %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + if (deadlock && cyclelen == 1) + pr_info("%s: Expect hang.\n", __func__); + for (i = 0; i < cyclelen; i++) { + char *fl = i == 0 ? "rcu_read_lock_trace" : "srcu_read_lock"; + char *fs = i == cyclelen - 1 ? "synchronize_rcu_tasks_trace" + : "synchronize_srcu"; + char *fu = i == 0 ? "rcu_read_unlock_trace" : "srcu_read_unlock"; + + j = srcu_lockdep_next(__func__, fl, fs, fu, i, cyclelen, deadlock); + if (i == 0) + rcu_read_lock_trace(); + else + idx = srcu_read_lock(srcus[i]); + if (j >= 0) { + if (i == cyclelen - 1) + synchronize_rcu_tasks_trace(); + else + synchronize_srcu(srcus[j]); + } + if (i == 0) + rcu_read_unlock_trace(); + else + srcu_read_unlock(srcus[i], idx); + } + return; + } +#endif // #ifdef CONFIG_TASKS_TRACE_RCU + +err_out: + pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep); + pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__); + pr_info("%s: D: Deadlock if nonzero.\n", __func__); + pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem, 3=SRCU/Tasks Trace RCU.\n", __func__); + pr_info("%s: L: Cycle length.\n", __func__); + if (!IS_ENABLED(CONFIG_TASKS_TRACE_RCU)) + pr_info("%s: NN=3 disallowed because kernel is built with CONFIG_TASKS_TRACE_RCU=n\n", __func__); } static int __init rcu_torture_init(void) { - int i; + long i; int cpu; int firsterr = 0; + int flags = 0; + unsigned long gp_seq = 0; static struct rcu_torture_ops *torture_ops[] = { - &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, - &sched_ops, RCUTORTURE_TASKS_OPS + &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops, + TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS + &trivial_ops, }; - if (!torture_init_begin(torture_type, verbose, &torture_runnable)) + if (!torture_init_begin(torture_type, verbose)) return -EBUSY; /* Process args and tell the world that the torturer is on the job. */ @@ -1766,18 +4465,35 @@ rcu_torture_init(void) torture_type); pr_alert("rcu-torture types:"); for (i = 0; i < ARRAY_SIZE(torture_ops); i++) - pr_alert(" %s", torture_ops[i]->name); - pr_alert("\n"); + pr_cont(" %s", torture_ops[i]->name); + pr_cont("\n"); firsterr = -EINVAL; + cur_ops = NULL; goto unwind; } if (cur_ops->fqs == NULL && fqs_duration != 0) { pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); fqs_duration = 0; } + if (nocbs_nthreads != 0 && (cur_ops != &rcu_ops || + !IS_ENABLED(CONFIG_RCU_NOCB_CPU))) { + pr_alert("rcu-torture types: %s and CONFIG_RCU_NOCB_CPU=%d, nocb toggle disabled.\n", + cur_ops->name, IS_ENABLED(CONFIG_RCU_NOCB_CPU)); + nocbs_nthreads = 0; + } if (cur_ops->init) cur_ops->init(); + rcu_torture_init_srcu_lockdep(); + + if (nfakewriters >= 0) { + nrealfakewriters = nfakewriters; + } else { + nrealfakewriters = num_online_cpus() - 2 - nfakewriters; + if (nrealfakewriters <= 0) + nrealfakewriters = 1; + } + if (nreaders >= 0) { nrealreaders = nreaders; } else { @@ -1786,6 +4502,11 @@ rcu_torture_init(void) nrealreaders = 1; } rcu_torture_print_module_parms(cur_ops, "Start of test"); + if (cur_ops->get_gp_data) + cur_ops->get_gp_data(&flags, &gp_seq); + start_gp_seq = gp_seq; + pr_alert("%s: Start-test grace-period state: g%ld f%#x\n", + cur_ops->name, (long)gp_seq, flags); /* Set up the freelist. */ @@ -1804,10 +4525,11 @@ rcu_torture_init(void) atomic_set(&n_rcu_torture_alloc_fail, 0); atomic_set(&n_rcu_torture_free, 0); atomic_set(&n_rcu_torture_mberror, 0); + atomic_set(&n_rcu_torture_mbchk_fail, 0); + atomic_set(&n_rcu_torture_mbchk_tries, 0); atomic_set(&n_rcu_torture_error, 0); n_rcu_torture_barrier_error = 0; n_rcu_torture_boost_ktrerror = 0; - n_rcu_torture_boost_rterror = 0; n_rcu_torture_boost_failure = 0; n_rcu_torture_boosts = 0; for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) @@ -1818,124 +4540,167 @@ rcu_torture_init(void) per_cpu(rcu_torture_batch, cpu)[i] = 0; } } + err_segs_recorded = 0; + rt_read_nsegs = 0; /* Start up the kthreads. */ - firsterr = torture_create_kthread(rcu_torture_writer, NULL, - writer_task); - if (firsterr) - goto unwind; - if (nfakewriters > 0) { - fakewriter_tasks = kzalloc(nfakewriters * + rcu_torture_write_types(); + if (nrealfakewriters > 0) { + fakewriter_tasks = kcalloc(nrealfakewriters, sizeof(fakewriter_tasks[0]), GFP_KERNEL); if (fakewriter_tasks == NULL) { - VERBOSE_TOROUT_ERRSTRING("out of memory"); + TOROUT_ERRSTRING("out of memory"); firsterr = -ENOMEM; goto unwind; } } - for (i = 0; i < nfakewriters; i++) { + for (i = 0; i < nrealfakewriters; i++) { firsterr = torture_create_kthread(rcu_torture_fakewriter, NULL, fakewriter_tasks[i]); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } - reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), + reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), GFP_KERNEL); - if (reader_tasks == NULL) { - VERBOSE_TOROUT_ERRSTRING("out of memory"); + rcu_torture_reader_mbchk = kcalloc(nrealreaders, sizeof(*rcu_torture_reader_mbchk), + GFP_KERNEL); + if (!reader_tasks || !rcu_torture_reader_mbchk) { + TOROUT_ERRSTRING("out of memory"); firsterr = -ENOMEM; goto unwind; } for (i = 0; i < nrealreaders; i++) { - firsterr = torture_create_kthread(rcu_torture_reader, NULL, + rcu_torture_reader_mbchk[i].rtc_chkrdr = -1; + firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, reader_tasks[i]); - if (firsterr) + if (torture_init_error(firsterr)) + goto unwind; + } + + firsterr = torture_create_kthread(rcu_torture_writer, NULL, + writer_task); + if (torture_init_error(firsterr)) + goto unwind; + + firsterr = rcu_torture_updown_init(); + if (torture_init_error(firsterr)) + goto unwind; + nrealnocbers = nocbs_nthreads; + if (WARN_ON(nrealnocbers < 0)) + nrealnocbers = 1; + if (WARN_ON(nocbs_toggle < 0)) + nocbs_toggle = HZ; + if (nrealnocbers > 0) { + nocb_tasks = kcalloc(nrealnocbers, sizeof(nocb_tasks[0]), GFP_KERNEL); + if (nocb_tasks == NULL) { + TOROUT_ERRSTRING("out of memory"); + firsterr = -ENOMEM; + goto unwind; + } + } else { + nocb_tasks = NULL; + } + for (i = 0; i < nrealnocbers; i++) { + firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]); + if (torture_init_error(firsterr)) goto unwind; } if (stat_interval > 0) { firsterr = torture_create_kthread(rcu_torture_stats, NULL, stats_task); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (test_no_idle_hz && shuffle_interval > 0) { firsterr = torture_shuffle_init(shuffle_interval * HZ); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (stutter < 0) stutter = 0; if (stutter) { - firsterr = torture_stutter_init(stutter * HZ); - if (firsterr) + int t; + + t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; + firsterr = torture_stutter_init(stutter * HZ, t); + if (torture_init_error(firsterr)) goto unwind; } if (fqs_duration < 0) fqs_duration = 0; - if (fqs_duration) { + if (fqs_holdoff < 0) + fqs_holdoff = 0; + if (fqs_duration && fqs_holdoff) { /* Create the fqs thread */ firsterr = torture_create_kthread(rcu_torture_fqs, NULL, fqs_task); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; } if (test_boost_interval < 1) test_boost_interval = 1; if (test_boost_duration < 2) test_boost_duration = 2; - if ((test_boost == 1 && cur_ops->can_boost) || - test_boost == 2) { + if (rcu_torture_can_boost()) { boost_starttime = jiffies + test_boost_interval * HZ; firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", rcutorture_booster_init, rcutorture_booster_cleanup); - if (firsterr < 0) - goto unwind; rcutor_hp = firsterr; + if (torture_init_error(firsterr)) + goto unwind; } + shutdown_jiffies = jiffies + shutdown_secs * HZ; firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; - firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ); - if (firsterr) + firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, + rcutorture_sync); + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_stall_init(); - if (firsterr) + if (torture_init_error(firsterr)) + goto unwind; + firsterr = rcu_torture_fwd_prog_init(); + if (torture_init_error(firsterr)) goto unwind; firsterr = rcu_torture_barrier_init(); - if (firsterr) + if (torture_init_error(firsterr)) goto unwind; + firsterr = rcu_torture_read_exit_init(); + if (torture_init_error(firsterr)) + goto unwind; + if (preempt_duration > 0) { + firsterr = torture_create_kthread(rcu_torture_preempt, NULL, preempt_task); + if (torture_init_error(firsterr)) + goto unwind; + } if (object_debug) rcu_test_debug_objects(); - if (cbflood_n_burst > 0) { - /* Create the cbflood threads */ - ncbflooders = (num_online_cpus() + 3) / 4; - cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task), - GFP_KERNEL); - if (!cbflood_task) { - VERBOSE_TOROUT_ERRSTRING("out of memory"); - firsterr = -ENOMEM; + + if (cur_ops->gp_slow_register && !WARN_ON_ONCE(!cur_ops->gp_slow_unregister)) + cur_ops->gp_slow_register(&rcu_fwd_cb_nodelay); + + if (gpwrap_lag && cur_ops->set_gpwrap_lag) { + firsterr = rcu_gpwrap_lag_init(); + if (torture_init_error(firsterr)) goto unwind; - } - for (i = 0; i < ncbflooders; i++) { - firsterr = torture_create_kthread(rcu_torture_cbflood, - NULL, - cbflood_task[i]); - if (firsterr) - goto unwind; - } } - rcutorture_record_test_transition(); + torture_init_end(); return 0; unwind: torture_init_end(); rcu_torture_cleanup(); + if (shutdown_secs) { + WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST)); + kernel_power_off(); + } return firsterr; } |