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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-09-11 15:33:05 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-11 20:17:18 +0200
commitf79e0258ea1f04d63db499479b5fb855dff6dbc5 (patch)
tree66edb089e5c3aee03e1326d41e47d7e14c21e76b
parente500011ffa191d662ac64d4ada6a5187b3180e16 (diff)
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 <schwidefsky@de.ibm.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090911153305.3fe9a361@skybase> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/time/clocksource.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index a0af4ffcb6e..5697155f186 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);