diff options
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 52 |
1 files changed, 13 insertions, 39 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index ebdbdec5911f..c6ea81cd4189 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -488,7 +488,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) empty_norm = !rcu_preempt_blocked_readers_cgp(rnp); WARN_ON_ONCE(rnp->completedqs == rnp->gp_seq && (!empty_norm || rnp->qsmask)); - empty_exp = sync_rcu_preempt_exp_done(rnp); + empty_exp = sync_rcu_exp_done(rnp); smp_mb(); /* ensure expedited fastpath sees end of RCU c-s. */ np = rcu_next_node_entry(t, rnp); list_del_init(&t->rcu_node_entry); @@ -512,7 +512,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) * Note that rcu_report_unblock_qs_rnp() releases rnp->lock, * so we must take a snapshot of the expedited state. */ - empty_exp_now = sync_rcu_preempt_exp_done(rnp); + empty_exp_now = sync_rcu_exp_done(rnp); if (!empty_norm && !rcu_preempt_blocked_readers_cgp(rnp)) { trace_rcu_quiescent_state_report(TPS("preempt_rcu"), rnp->gp_seq, @@ -1264,10 +1264,9 @@ static void rcu_prepare_for_idle(void) /* * This code is invoked when a CPU goes idle, at which point we want * to have the CPU do everything required for RCU so that it can enter - * the energy-efficient dyntick-idle mode. This is handled by a - * state machine implemented by rcu_prepare_for_idle() below. + * the energy-efficient dyntick-idle mode. * - * The following three proprocessor symbols control this state machine: + * The following preprocessor symbol controls this: * * RCU_IDLE_GP_DELAY gives the number of jiffies that a CPU is permitted * to sleep in dyntick-idle mode with RCU callbacks pending. This @@ -1276,21 +1275,15 @@ static void rcu_prepare_for_idle(void) * number, be warned: Setting RCU_IDLE_GP_DELAY too high can hang your * system. And if you are -that- concerned about energy efficiency, * just power the system down and be done with it! - * RCU_IDLE_LAZY_GP_DELAY gives the number of jiffies that a CPU is - * permitted to sleep in dyntick-idle mode with only lazy RCU - * callbacks pending. Setting this too high can OOM your system. * - * The values below work well in practice. If future workloads require + * The value below works well in practice. If future workloads require * adjustment, they can be converted into kernel config parameters, though * making the state machine smarter might be a better option. */ #define RCU_IDLE_GP_DELAY 4 /* Roughly one grace period. */ -#define RCU_IDLE_LAZY_GP_DELAY (6 * HZ) /* Roughly six seconds. */ static int rcu_idle_gp_delay = RCU_IDLE_GP_DELAY; module_param(rcu_idle_gp_delay, int, 0644); -static int rcu_idle_lazy_gp_delay = RCU_IDLE_LAZY_GP_DELAY; -module_param(rcu_idle_lazy_gp_delay, int, 0644); /* * Try to advance callbacks on the current CPU, but only if it has been @@ -1329,8 +1322,7 @@ static bool __maybe_unused rcu_try_advance_all_cbs(void) /* * Allow the CPU to enter dyntick-idle mode unless it has callbacks ready * to invoke. If the CPU has callbacks, try to advance them. Tell the - * caller to set the timeout based on whether or not there are non-lazy - * callbacks. + * caller about what to set the timeout. * * The caller must have disabled interrupts. */ @@ -1356,25 +1348,18 @@ int rcu_needs_cpu(u64 basemono, u64 *nextevt) } rdp->last_accelerate = jiffies; - /* Request timer delay depending on laziness, and round. */ - rdp->all_lazy = !rcu_segcblist_n_nonlazy_cbs(&rdp->cblist); - if (rdp->all_lazy) { - dj = round_jiffies(rcu_idle_lazy_gp_delay + jiffies) - jiffies; - } else { - dj = round_up(rcu_idle_gp_delay + jiffies, - rcu_idle_gp_delay) - jiffies; - } + /* Request timer and round. */ + dj = round_up(rcu_idle_gp_delay + jiffies, rcu_idle_gp_delay) - jiffies; + *nextevt = basemono + dj * TICK_NSEC; return 0; } /* - * Prepare a CPU for idle from an RCU perspective. The first major task - * is to sense whether nohz mode has been enabled or disabled via sysfs. - * The second major task is to check to see if a non-lazy callback has - * arrived at a CPU that previously had only lazy callbacks. The third - * major task is to accelerate (that is, assign grace-period numbers to) - * any recently arrived callbacks. + * Prepare a CPU for idle from an RCU perspective. The first major task is to + * sense whether nohz mode has been enabled or disabled via sysfs. The second + * major task is to accelerate (that is, assign grace-period numbers to) any + * recently arrived callbacks. * * The caller must have disabled interrupts. */ @@ -1401,17 +1386,6 @@ static void rcu_prepare_for_idle(void) return; /* - * If a non-lazy callback arrived at a CPU having only lazy - * callbacks, invoke RCU core for the side-effect of recalculating - * idle duration on re-entry to idle. - */ - if (rdp->all_lazy && rcu_segcblist_n_nonlazy_cbs(&rdp->cblist)) { - rdp->all_lazy = false; - invoke_rcu_core(); - return; - } - - /* * If we have not yet accelerated this jiffy, accelerate all * callbacks on this CPU. */ |