Commit-ID: f6c3f1686e7ec1dd8725a9a3dcb857dfd0c7a5bf Gitweb: http://git.kernel.org/tip/f6c3f1686e7ec1dd8725a9a3dcb857dfd0c7a5bf Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> AuthorDate: Mon, 13 Sep 2010 11:02:21 -0700 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 21 Sep 2010 13:50:50 +0200 sched: Fix nohz balance kick There's a situation where the nohz balancer will try to wake itself: cpu-x is idle which is also ilb_cpu got a scheduler tick during idle and the nohz_kick_needed() in trigger_load_balance() checks for rq_x->nr_running which might not be zero (because of someone waking a task on this rq etc) and this leads to the situation of the cpu-x sending a kick to itself. And this can cause a lockup. Avoid this by not marking ourself eligible for kicking. Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> LKML-Reference: <1284400941.2684.19.camel@xxxxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/sched_fair.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a171138..db3f674 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -3630,7 +3630,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu) if (time_before(now, nohz.next_balance)) return 0; - if (!rq->nr_running) + if (rq->idle_at_tick) return 0; first_pick_cpu = atomic_read(&nohz.first_pick_cpu); -- 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
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