3.6-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <[email protected]> commit 08bedae1d0acd8c9baf514fb69fa199d0c8345f6 upstream. Commit f319da0c68 ("sched: Fix load avg vs cpu-hotplug") was an incomplete fix: In particular, the problem is that at the point it calls calc_load_migrate() nr_running := 1 (the stopper thread), so move the call to CPU_DEAD where we're sure that nr_running := 0. Also note that we can call calc_load_migrate() without serialization, we know the state of rq is stable since its cpu is dead, and we modify the global state using appropriate atomic ops. Suggested-by: Paul E. McKenney <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/1346882630.2600.59.camel@twins Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/sched/core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5604,7 +5604,9 @@ migration_call(struct notifier_block *nf migrate_tasks(cpu); BUG_ON(rq->nr_running != 1); /* the migration thread */ raw_spin_unlock_irqrestore(&rq->lock, flags); + break; + case CPU_DEAD: calc_load_migrate(rq); break; #endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
