When updating avg_idle, if the delta exceeds some max value, then avg_idle gets set to the max, regardless of what the previous avg was. This can cause avg_idle to often be overestimated.
This patch modifies the way we update avg_idle by always updating it with the function call to update_avg() first. Then, if avg_idle exceeds the max, we set it to the max. Signed-off-by: Jason Low <[email protected]> Reviewed-by: Rik van Riel <[email protected]> --- kernel/sched/core.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 05c39f0..93b18ef 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1347,10 +1347,11 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) u64 delta = rq_clock(rq) - rq->idle_stamp; u64 max = 2*sysctl_sched_migration_cost; - if (delta > max) + update_avg(&rq->avg_idle, delta); + + if (rq->avg_idle > max) rq->avg_idle = max; - else - update_avg(&rq->avg_idle, delta); + rq->idle_stamp = 0; } #endif -- 1.7.1 -- 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/
