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authorIngo Molnar <mingo@kernel.org>2013-12-04 10:09:53 +0100
committerIngo Molnar <mingo@kernel.org>2013-12-04 10:09:53 +0100
commita934a56e1284f1863c9c800ff9c63183c25aec93 (patch)
tree643ffbf749b8b9d68e1b8641c6d179f535b9f9c0 /kernel/posix-cpu-timers.c
parentdea4f48a0a301b23c65af8e4fe8ccf360c272fbf (diff)
parentc925077c33fc9a546e7cf6c3be2adf4a2afe2608 (diff)
Merge branch 'timers/core-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core
Pull dynticks updates from Frederic Weisbecker: * Fix a bug where posix cpu timers requeued due to interval got ignored on full dynticks CPUs (not a regression though as it only impacts full dynticks and the bug is there since we merged full dynticks). * Optimizations and cleanups on the use of per CPU APIs to improve code readability, performance and debuggability in the nohz subsystem; * Optimize posix cpu timer by sparing stub workqueue queue with full dynticks off case * Rename some functions to extend with *_this_cpu() suffix for clarity * Refine the naming of some context tracking subsystem state accessors * Trivial spelling fix by Paul Gortmaker Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/posix-cpu-timers.c')
-rw-r--r--kernel/posix-cpu-timers.c21
1 files changed, 9 insertions, 12 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c7f31aa272f..79747b7d942 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -608,7 +608,8 @@ static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);
*/
static void posix_cpu_timer_kick_nohz(void)
{
- schedule_work(&nohz_kick_work);
+ if (context_tracking_is_enabled())
+ schedule_work(&nohz_kick_work);
}
bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
@@ -1090,7 +1091,8 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
put_task_struct(p);
timer->it.cpu.task = p = NULL;
timer->it.cpu.expires = 0;
- goto out_unlock;
+ read_unlock(&tasklist_lock);
+ goto out;
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
/*
* We've noticed that the thread is dead, but
@@ -1099,7 +1101,8 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
*/
cpu_timer_sample_group(timer->it_clock, p, &now);
clear_dead_task(timer, now);
- goto out_unlock;
+ read_unlock(&tasklist_lock);
+ goto out;
}
spin_lock(&p->sighand->siglock);
cpu_timer_sample_group(timer->it_clock, p, &now);
@@ -1113,10 +1116,11 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
BUG_ON(!irqs_disabled());
arm_timer(timer);
spin_unlock(&p->sighand->siglock);
-
-out_unlock:
read_unlock(&tasklist_lock);
+ /* Kick full dynticks CPUs in case they need to tick on the new timer */
+ posix_cpu_timer_kick_nohz();
+
out:
timer->it_overrun_last = timer->it_overrun;
timer->it_overrun = -1;
@@ -1256,13 +1260,6 @@ void run_posix_cpu_timers(struct task_struct *tsk)
cpu_timer_fire(timer);
spin_unlock(&timer->it_lock);
}
-
- /*
- * In case some timers were rescheduled after the queue got emptied,
- * wake up full dynticks CPUs.
- */
- if (tsk->signal->cputimer.running)
- posix_cpu_timer_kick_nohz();
}
/*