From cd05a1f818073a623455a58e756c5b419fc98db9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 17 Mar 2007 00:25:52 +0100 Subject: [PATCH] clockevents: Fix suspend/resume to disk hangs I finally found a dual core box, which survives suspend/resume without crashing in the middle of nowhere. Sigh, I never figured out from the code and the bug reports what's going on. The observed hangs are caused by a stale state transition of the clock event devices, which keeps the RCU synchronization away from completion, when the non boot CPU is brought back up. The suspend/resume in oneshot mode needs the similar care as the periodic mode during suspend to RAM. My assumption that the state transitions during the different shutdown/bringups of s2disk would go through the periodic boot phase and then switch over to highres resp. nohz mode were simply wrong. Add the appropriate suspend / resume handling for the non periodic modes. Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds --- kernel/time/tick-common.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'kernel/time/tick-common.c') diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 43ba1bdec14..bfda3f7f071 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -298,18 +298,17 @@ static void tick_shutdown(unsigned int *cpup) spin_unlock_irqrestore(&tick_device_lock, flags); } -static void tick_suspend_periodic(void) +static void tick_suspend(void) { struct tick_device *td = &__get_cpu_var(tick_cpu_device); unsigned long flags; spin_lock_irqsave(&tick_device_lock, flags); - if (td->mode == TICKDEV_MODE_PERIODIC) - clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN); spin_unlock_irqrestore(&tick_device_lock, flags); } -static void tick_resume_periodic(void) +static void tick_resume(void) { struct tick_device *td = &__get_cpu_var(tick_cpu_device); unsigned long flags; @@ -317,6 +316,8 @@ static void tick_resume_periodic(void) spin_lock_irqsave(&tick_device_lock, flags); if (td->mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(td->evtdev, 0); + else + tick_resume_oneshot(); spin_unlock_irqrestore(&tick_device_lock, flags); } @@ -348,13 +349,13 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason, break; case CLOCK_EVT_NOTIFY_SUSPEND: - tick_suspend_periodic(); + tick_suspend(); tick_suspend_broadcast(); break; case CLOCK_EVT_NOTIFY_RESUME: if (!tick_resume_broadcast()) - tick_resume_periodic(); + tick_resume(); break; default: -- cgit v1.2.3