From cd4ae6adf8b1c21d88e83ed56afeeef97b28f356 Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Fri, 22 Apr 2011 18:53:54 +0800 Subject: sched: More sched_domain iterations fixes sched_domain iterations needs to be protected by rcu_read_lock() now, this patch adds another two places which needs the rcu lock, which is spotted by following suspicious rcu_dereference_check() usage warnings. kernel/sched_rt.c:1244 invoked rcu_dereference_check() without protection! kernel/sched_stats.h:41 invoked rcu_dereference_check() without protection! Signed-off-by: Xiaotian Feng Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1303469634-11678-1-git-send-email-dfeng@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched_rt.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel/sched_rt.c') diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 64b2a37..88725c9 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1263,6 +1263,7 @@ static int find_lowest_rq(struct task_struct *task) if (!cpumask_test_cpu(this_cpu, lowest_mask)) this_cpu = -1; /* Skip this_cpu opt if not among lowest */ + rcu_read_lock(); for_each_domain(cpu, sd) { if (sd->flags & SD_WAKE_AFFINE) { int best_cpu; @@ -1272,15 +1273,20 @@ static int find_lowest_rq(struct task_struct *task) * remote processor. */ if (this_cpu != -1 && - cpumask_test_cpu(this_cpu, sched_domain_span(sd))) + cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { + rcu_read_unlock(); return this_cpu; + } best_cpu = cpumask_first_and(lowest_mask, sched_domain_span(sd)); - if (best_cpu < nr_cpu_ids) + if (best_cpu < nr_cpu_ids) { + rcu_read_unlock(); return best_cpu; + } } } + rcu_read_unlock(); /* * And finally, if there were no matches within the domains -- cgit v1.1