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| author | Jason Low <jason.low2@hp.com> | 2013-09-13 11:26:51 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-09-20 12:03:41 +0200 |
| commit | abfafa54db9aba404e8e6763503f04d35bd07138 (patch) | |
| tree | 64a965459a5de970ff15265a9cd9f436591cadde /kernel | |
| parent | 7aff2e3a56b724b79fa2d5abd10d8231ef8fb0c5 (diff) | |
| download | lwn-abfafa54db9aba404e8e6763503f04d35bd07138.tar.gz lwn-abfafa54db9aba404e8e6763503f04d35bd07138.zip | |
sched: Reduce overestimating rq->avg_idle
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 <jason.low2@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1379096813-3032-2-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | 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 5ac63c9a995a..048f39e45761 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1332,10 +1332,11 @@ 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 |