2.6.24-stable review patch. If anyone has any objections, please let us know. ------------------ From: Srivatsa Vaddagiri patch 296825cbe14d4c95ee9c41ca5824f7487bfb4d9d in mainline. The reason why we are getting better wakeup latencies for !FAIR_USER_SCHED is because of this snippet of code in place_entity(): if (!initial) { /* sleeps upto a single latency don't count. */ if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se)) ^^^^^^^^^^^^^^^^^^ vruntime -= sysctl_sched_latency; /* ensure we never gain time by being placed backwards. */ vruntime = max_vruntime(se->vruntime, vruntime); } NEW_FAIR_SLEEPERS feature gives credit for sleeping only to tasks and not group-level entities. With the patch attached, I could see that wakeup latencies with FAIR_USER_SCHED are restored to the same level as !FAIR_USER_SCHED. Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/sched_fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -511,7 +511,7 @@ place_entity(struct cfs_rq *cfs_rq, stru if (!initial) { /* sleeps upto a single latency don't count. */ - if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se)) + if (sched_feat(NEW_FAIR_SLEEPERS)) vruntime -= sysctl_sched_latency; /* ensure we never gain time by being placed backwards. */ -- -- 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/