From 6ea41d252f35465a2308a4038a323b6b07de06f6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 15 Aug 2009 13:20:42 +0200 Subject: [PATCH] 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 --- kernel/time/clocksource.c | 11 +++++++++-- 1 file 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 */ -- 2.7.4