Commit-ID: 6ea41d252f35465a2308a4038a323b6b07de06f6
Gitweb: http://git.kernel.org/tip/6ea41d252f35465a2308a4038a323b6b07de06f6
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sat, 15 Aug 2009 13:20:42 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sat, 15 Aug 2009 13:20:42 +0200
clocksource: Call clocksource_change_rating() outside of watchdog_lock
The changes to the watchdog logic introduced a lock inversion between
watchdog_lock and clocksource_mutex. Change the rating outside of
watchdog_lock to avoid it.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/time/clocksource.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index a1657b5..02dc22d 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -307,16 +307,23 @@ static void clocksource_watchdog_work(struct work_struct *work)
{
struct clocksource *cs, *tmp;
unsigned long flags;
+ LIST_HEAD(unstable);
spin_lock_irqsave(&watchdog_lock, flags);
list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list)
if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
list_del_init(&cs->wd_list);
- clocksource_change_rating(cs, 0);
+ list_add(&cs->wd_list, &unstable);
}
/* Check if the watchdog timer needs to be stopped. */
clocksource_stop_watchdog();
- spin_unlock(&watchdog_lock);
+ spin_unlock_irqrestore(&watchdog_lock, flags);
+
+ /* Needs to be done outside of watchdog lock */
+ list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
+ list_del_init(&cs->wd_list);
+ clocksource_change_rating(cs, 0);
+ }
}
#else /* CONFIG_CLOCKSOURCE_WATCHDOG */
--
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