From f79e0258ea1f04d63db499479b5fb855dff6dbc5 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 11 Sep 2009 15:33:05 +0200 Subject: clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crash The watchdog timer is started after the watchdog clocksource and at least one watched clocksource have been registered. The clocksource work element watchdog_work is initialized just before the clocksource timer is started. This is too late for the clocksource_mark_unstable call from native_cpu_up. To fix this use a static initializer for watchdog_work. This resolves a boot crash reported by multiple people. Signed-off-by: Martin Schwidefsky Cc: Jens Axboe Cc: John Stultz LKML-Reference: <20090911153305.3fe9a361@skybase> Signed-off-by: Ingo Molnar --- kernel/time/clocksource.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index a0af4ffcb6e5..5697155f1868 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -123,10 +123,12 @@ static DEFINE_MUTEX(clocksource_mutex); static char override_name[32]; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG +static void clocksource_watchdog_work(struct work_struct *work); + static LIST_HEAD(watchdog_list); static struct clocksource *watchdog; static struct timer_list watchdog_timer; -static struct work_struct watchdog_work; +static DECLARE_WORK(watchdog_work, clocksource_watchdog_work); static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; static int watchdog_running; @@ -257,7 +259,6 @@ static inline void clocksource_start_watchdog(void) { if (watchdog_running || !watchdog || list_empty(&watchdog_list)) return; - INIT_WORK(&watchdog_work, clocksource_watchdog_work); init_timer(&watchdog_timer); watchdog_timer.function = clocksource_watchdog; watchdog_last = watchdog->read(watchdog); -- cgit v1.2.3-58-ga151