Context-switch intensive microbenchmark on a 8-socket system had ~600K times more resched IPI's on each logical CPU with this feature enabled by default. Disabling this features makes that microbenchmark perform 5 times better. Also disabling this feature showed 2% performance improvement on a 8-socket OLTP workload. More heurestics are needed when and how to use this feature by default. For now, disable it by default. Signed-off-by: Suresh Siddha --- kernel/sched/features.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: tip/kernel/sched/features.h =================================================================== --- tip.orig/kernel/sched/features.h +++ tip/kernel/sched/features.h @@ -64,7 +64,7 @@ SCHED_FEAT(NONTASK_POWER, 1) * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ -SCHED_FEAT(TTWU_QUEUE, 1) +SCHED_FEAT(TTWU_QUEUE, 0) SCHED_FEAT(FORCE_SD_OVERLAP, 0) SCHED_FEAT(RT_RUNTIME_SHARE, 1) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/