Commit-ID: 83f54960c11a14942ab00b54c51e91906b9d8235 Gitweb: http://git.kernel.org/tip/83f54960c11a14942ab00b54c51e91906b9d8235 Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> AuthorDate: Thu, 10 Sep 2009 18:18:47 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 15 Sep 2009 16:01:06 +0200 sched: for_each_domain() vs RCU for_each_domain() uses RCU to serialize the sched_domains, except it doesn't actually use rcu_read_lock() and instead relies on disabling preemption -> FAIL. XXX: audit other sched_domain code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/sched_fair.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index eaa0001..43dc6d1 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1331,6 +1331,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) new_cpu = prev_cpu; } + rcu_read_lock(); for_each_domain(cpu, tmp) { /* * If power savings logic is enabled for a domain, see if we @@ -1369,8 +1370,10 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { - if (wake_affine(tmp, p, sync)) - return cpu; + if (wake_affine(tmp, p, sync)) { + new_cpu = cpu; + goto out; + } want_affine = 0; } @@ -1416,6 +1419,8 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) /* while loop will break here if sd == NULL */ } +out: + rcu_read_unlock(); return new_cpu; } #endif /* CONFIG_SMP */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html