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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-17 12:35:15 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-17 12:35:15 -0700 |
commit | 7f2444d38f6bbfa12bc15e2533d8f9daa85ca02b (patch) | |
tree | 6506ec79036890edfd9797b001391a350b5ac10f /include/linux/posix-timers.h | |
parent | c5f12fdb8bd873aa3ffdb79512e6bdac92b257b0 (diff) | |
parent | 77b4b5420422fc037d00b8f3f0e89b2262e4ae29 (diff) |
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core timer updates from Thomas Gleixner:
"Timers and timekeeping updates:
- A large overhaul of the posix CPU timer code which is a preparation
for moving the CPU timer expiry out into task work so it can be
properly accounted on the task/process.
An update to the bogus permission checks will come later during the
merge window as feedback was not complete before heading of for
travel.
- Switch the timerqueue code to use cached rbtrees and get rid of the
homebrewn caching of the leftmost node.
- Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a
single function
- Implement the separation of hrtimers to be forced to expire in hard
interrupt context even when PREEMPT_RT is enabled and mark the
affected timers accordingly.
- Implement a mechanism for hrtimers and the timer wheel to protect
RT against priority inversion and live lock issues when a (hr)timer
which should be canceled is currently executing the callback.
Instead of infinitely spinning, the task which tries to cancel the
timer blocks on a per cpu base expiry lock which is held and
released by the (hr)timer expiry code.
- Enable the Hyper-V TSC page based sched_clock for Hyper-V guests
resulting in faster access to timekeeping functions.
- Updates to various clocksource/clockevent drivers and their device
tree bindings.
- The usual small improvements all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
posix-cpu-timers: Fix permission check regression
posix-cpu-timers: Always clear head pointer on dequeue
hrtimer: Add a missing bracket and hide `migration_base' on !SMP
posix-cpu-timers: Make expiry_active check actually work correctly
posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build
tick: Mark sched_timer to expire in hard interrupt context
hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD
x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n
posix-cpu-timers: Utilize timerqueue for storage
posix-cpu-timers: Move state tracking to struct posix_cputimers
posix-cpu-timers: Deduplicate rlimit handling
posix-cpu-timers: Remove pointless comparisons
posix-cpu-timers: Get rid of 64bit divisions
posix-cpu-timers: Consolidate timer expiry further
posix-cpu-timers: Get rid of zero checks
rlimit: Rewrite non-sensical RLIMIT_CPU comment
posix-cpu-timers: Respect INFINITY for hard RTTIME limit
posix-cpu-timers: Switch thread group sampling to array
posix-cpu-timers: Restructure expiry array
posix-cpu-timers: Remove cputime_expires
...
Diffstat (limited to 'include/linux/posix-timers.h')
-rw-r--r-- | include/linux/posix-timers.h | 131 |
1 files changed, 117 insertions, 14 deletions
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index b20798fc5191..3d10c84a97a9 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -4,18 +4,11 @@ #include <linux/spinlock.h> #include <linux/list.h> -#include <linux/sched.h> -#include <linux/timex.h> #include <linux/alarmtimer.h> +#include <linux/timerqueue.h> -struct siginfo; - -struct cpu_timer_list { - struct list_head entry; - u64 expires; - struct task_struct *task; - int firing; -}; +struct kernel_siginfo; +struct task_struct; /* * Bit fields within a clockid: @@ -63,6 +56,115 @@ static inline int clockid_to_fd(const clockid_t clk) return ~(clk >> 3); } +#ifdef CONFIG_POSIX_TIMERS + +/** + * cpu_timer - Posix CPU timer representation for k_itimer + * @node: timerqueue node to queue in the task/sig + * @head: timerqueue head on which this timer is queued + * @task: Pointer to target task + * @elist: List head for the expiry list + * @firing: Timer is currently firing + */ +struct cpu_timer { + struct timerqueue_node node; + struct timerqueue_head *head; + struct task_struct *task; + struct list_head elist; + int firing; +}; + +static inline bool cpu_timer_enqueue(struct timerqueue_head *head, + struct cpu_timer *ctmr) +{ + ctmr->head = head; + return timerqueue_add(head, &ctmr->node); +} + +static inline void cpu_timer_dequeue(struct cpu_timer *ctmr) +{ + if (ctmr->head) { + timerqueue_del(ctmr->head, &ctmr->node); + ctmr->head = NULL; + } +} + +static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr) +{ + return ctmr->node.expires; +} + +static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp) +{ + ctmr->node.expires = exp; +} + +/** + * posix_cputimer_base - Container per posix CPU clock + * @nextevt: Earliest-expiration cache + * @tqhead: timerqueue head for cpu_timers + */ +struct posix_cputimer_base { + u64 nextevt; + struct timerqueue_head tqhead; +}; + +/** + * posix_cputimers - Container for posix CPU timer related data + * @bases: Base container for posix CPU clocks + * @timers_active: Timers are queued. + * @expiry_active: Timer expiry is active. Used for + * process wide timers to avoid multiple + * task trying to handle expiry concurrently + * + * Used in task_struct and signal_struct + */ +struct posix_cputimers { + struct posix_cputimer_base bases[CPUCLOCK_MAX]; + unsigned int timers_active; + unsigned int expiry_active; +}; + +static inline void posix_cputimers_init(struct posix_cputimers *pct) +{ + memset(pct, 0, sizeof(*pct)); + pct->bases[0].nextevt = U64_MAX; + pct->bases[1].nextevt = U64_MAX; + pct->bases[2].nextevt = U64_MAX; +} + +void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit); + +static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, + u64 runtime) +{ + pct->bases[CPUCLOCK_SCHED].nextevt = runtime; +} + +/* Init task static initializer */ +#define INIT_CPU_TIMERBASE(b) { \ + .nextevt = U64_MAX, \ +} + +#define INIT_CPU_TIMERBASES(b) { \ + INIT_CPU_TIMERBASE(b[0]), \ + INIT_CPU_TIMERBASE(b[1]), \ + INIT_CPU_TIMERBASE(b[2]), \ +} + +#define INIT_CPU_TIMERS(s) \ + .posix_cputimers = { \ + .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \ + }, +#else +struct posix_cputimers { }; +struct cpu_timer { }; +#define INIT_CPU_TIMERS(s) +static inline void posix_cputimers_init(struct posix_cputimers *pct) { } +static inline void posix_cputimers_group_init(struct posix_cputimers *pct, + u64 cpu_limit) { } +#endif + #define REQUEUE_PENDING 1 /** @@ -85,7 +187,8 @@ static inline int clockid_to_fd(const clockid_t clk) * @it_process: The task to wakeup on clock_nanosleep (CPU timers) * @sigq: Pointer to preallocated sigqueue * @it: Union representing the various posix timer type - * internals. Also used for rcu freeing the timer. + * internals. + * @rcu: RCU head for freeing the timer. */ struct k_itimer { struct list_head list; @@ -110,15 +213,15 @@ struct k_itimer { struct { struct hrtimer timer; } real; - struct cpu_timer_list cpu; + struct cpu_timer cpu; struct { struct alarm alarmtimer; } alarm; - struct rcu_head rcu; } it; + struct rcu_head rcu; }; -void run_posix_cpu_timers(struct task_struct *task); +void run_posix_cpu_timers(void); void posix_cpu_timers_exit(struct task_struct *task); void posix_cpu_timers_exit_group(struct task_struct *task); void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx, |