* [patch] high-res timers: core, do itimer rearming in process context, fix
@ 2006-12-19 21:16 Ingo Molnar
2006-12-21 7:15 ` [patch] high-res timers: core, do itimer rearming in process context, fix2 Thomas Gleixner
0 siblings, 1 reply; 2+ messages in thread
From: Ingo Molnar @ 2006-12-19 21:16 UTC (permalink / raw)
To: Andrew Morton; +Cc: Thomas Gleixner, linux-kernel
Subject: [patch] high-res timers: core, do itimer rearming in process context, fix
From: Ingo Molnar <mingo@elte.hu>
restart itimers when they are not queued. (a non-queued hrtimer might
be callback-pending - but in that case we already missed the rearming
so the SIGALRM branch has to rearm.)
this fixes a threaded itimers stress-test hang.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/hrtimer.h | 9 +++++++++
kernel/hrtimer.c | 9 ---------
kernel/signal.c | 2 +-
3 files changed, 10 insertions(+), 10 deletions(-)
Index: linux/include/linux/hrtimer.h
===================================================================
--- linux.orig/include/linux/hrtimer.h
+++ linux/include/linux/hrtimer.h
@@ -309,6 +309,15 @@ static inline int hrtimer_active(const s
return timer->state != HRTIMER_STATE_INACTIVE;
}
+/*
+ * Helper function to check, whether the timer is on one of the queues
+ */
+static inline int hrtimer_is_queued(struct hrtimer *timer)
+{
+ return timer->state &
+ (HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING);
+}
+
/* Forward a hrtimer so it expires after now: */
extern unsigned long
hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
Index: linux/kernel/hrtimer.c
===================================================================
--- linux.orig/kernel/hrtimer.c
+++ linux/kernel/hrtimer.c
@@ -152,15 +152,6 @@ static void hrtimer_get_softirq_time(str
}
/*
- * Helper function to check, whether the timer is on one of the queues
- */
-static inline int hrtimer_is_queued(struct hrtimer *timer)
-{
- return timer->state &
- (HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING);
-}
-
-/*
* Helper function to check, whether the timer is running the callback
* function
*/
Index: linux/kernel/signal.c
===================================================================
--- linux.orig/kernel/signal.c
+++ linux/kernel/signal.c
@@ -475,7 +475,7 @@ int dequeue_signal(struct task_struct *t
if (unlikely(signr == SIGALRM)) {
struct hrtimer *tmr = &tsk->signal->real_timer;
- if (!hrtimer_active(tmr) &&
+ if (!hrtimer_is_queued(tmr) &&
tsk->signal->it_real_incr.tv64 != 0) {
hrtimer_forward(tmr, hrtimer_cb_get_time(tmr),
tsk->signal->it_real_incr);
^ permalink raw reply [flat|nested] 2+ messages in thread
* [patch] high-res timers: core, do itimer rearming in process context, fix2
2006-12-19 21:16 [patch] high-res timers: core, do itimer rearming in process context, fix Ingo Molnar
@ 2006-12-21 7:15 ` Thomas Gleixner
0 siblings, 0 replies; 2+ messages in thread
From: Thomas Gleixner @ 2006-12-21 7:15 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Andrew Morton, linux-kernel
Subject: [patch] high-res timers: core, do itimer rearming in process context, fix2
From: Thomas Gleixner <tglx@linutronix.de>
The rearming code in signal.c has to read the time and can not rely on
the timer->base->softirq time anymore, as it is not longer running in
softirq context.
Ensure, that the it_real_incr variable in the shared signal struct is
set to zero, when setitimer disables the itimer. Otherwise it could
happen that an inactive itimer gets rearmed by a SIGALRM.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: 2.6.19-git19/kernel/signal.c
===================================================================
--- 2.6.19-git19.orig/kernel/signal.c
+++ 2.6.19-git19/kernel/signal.c
@@ -477,7 +477,7 @@ int dequeue_signal(struct task_struct *t
if (!hrtimer_is_queued(tmr) &&
tsk->signal->it_real_incr.tv64 != 0) {
- hrtimer_forward(tmr, hrtimer_cb_get_time(tmr),
+ hrtimer_forward(tmr, tmr->base->get_time(),
tsk->signal->it_real_incr);
hrtimer_restart(tmr);
}
Index: 2.6.19-git19/kernel/itimer.c
===================================================================
--- 2.6.19-git19.orig/kernel/itimer.c
+++ 2.6.19-git19/kernel/itimer.c
@@ -226,11 +226,14 @@ again:
spin_unlock_irq(&tsk->sighand->siglock);
goto again;
}
- tsk->signal->it_real_incr =
- timeval_to_ktime(value->it_interval);
expires = timeval_to_ktime(value->it_value);
- if (expires.tv64 != 0)
+ if (expires.tv64 != 0) {
+ tsk->signal->it_real_incr =
+ timeval_to_ktime(value->it_interval);
hrtimer_start(timer, expires, HRTIMER_MODE_REL);
+ } else
+ tsk->signal->it_real_incr.tv64 = 0;
+
spin_unlock_irq(&tsk->sighand->siglock);
break;
case ITIMER_VIRTUAL:
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2006-12-21 7:11 UTC | newest]
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2006-12-19 21:16 [patch] high-res timers: core, do itimer rearming in process context, fix Ingo Molnar
2006-12-21 7:15 ` [patch] high-res timers: core, do itimer rearming in process context, fix2 Thomas Gleixner
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