From 89f19f04dc72363d912fd007a399cb10310eff6e Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sat, 19 Sep 2009 11:55:44 -0700 Subject: sched: Fix raciness in runqueue_is_locked() runqueue_is_locked() is unavoidably racy due to a poor interface design. It does cpu = get_cpu() ret = some_perpcu_thing(cpu); put_cpu(cpu); return ret; Its return value is unreliable. Fix. Signed-off-by: Andrew Morton Acked-by: Steven Rostedt Cc: Peter Zijlstra LKML-Reference: <200909191855.n8JItiko022148@imap1.linux-foundation.org> Signed-off-by: Ingo Molnar --- kernel/sched.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'kernel/sched.c') diff --git a/kernel/sched.c b/kernel/sched.c index faf4d463bbff..575fb0139038 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq) * This interface allows printk to be called with the runqueue lock * held and know whether or not it is OK to wake up the klogd. */ -int runqueue_is_locked(void) +int runqueue_is_locked(int cpu) { - int cpu = get_cpu(); - struct rq *rq = cpu_rq(cpu); - int ret; - - ret = spin_is_locked(&rq->lock); - put_cpu(); - return ret; + return spin_is_locked(&cpu_rq(cpu)->lock); } /* -- cgit v1.2.3