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author | Paul Turner <pjt@google.com> | 2012-10-04 13:18:30 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-10-24 10:27:22 +0200 |
commit | 9ee474f55664ff63111c843099d365e7ecffb56f (patch) | |
tree | 745a678b0d3cd72ba42b67d0b6ac6c3872b14229 /kernel/sched/core.c | |
parent | 2dac754e10a5d41d94d2d2365c0345d4f215a266 (diff) | |
download | linux-9ee474f55664ff63111c843099d365e7ecffb56f.tar.gz linux-9ee474f55664ff63111c843099d365e7ecffb56f.tar.bz2 linux-9ee474f55664ff63111c843099d365e7ecffb56f.zip |
sched: Maintain the load contribution of blocked entities
We are currently maintaining:
runnable_load(cfs_rq) = \Sum task_load(t)
For all running children t of cfs_rq. While this can be naturally updated for
tasks in a runnable state (as they are scheduled); this does not account for
the load contributed by blocked task entities.
This can be solved by introducing a separate accounting for blocked load:
blocked_load(cfs_rq) = \Sum runnable(b) * weight(b)
Obviously we do not want to iterate over all blocked entities to account for
their decay, we instead observe that:
runnable_load(t) = \Sum p_i*y^i
and that to account for an additional idle period we only need to compute:
y*runnable_load(t).
This means that we can compute all blocked entities at once by evaluating:
blocked_load(cfs_rq)` = y * blocked_load(cfs_rq)
Finally we maintain a decay counter so that when a sleeping entity re-awakens
we can determine how much of its load should be removed from the blocked sum.
Signed-off-by: Paul Turner <pjt@google.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.585389902@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r-- | kernel/sched/core.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fd9d0859350a..00898f1fb69e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1528,7 +1528,6 @@ static void __sched_fork(struct task_struct *p) p->se.avg.runnable_avg_period = 0; p->se.avg.runnable_avg_sum = 0; #endif - #ifdef CONFIG_SCHEDSTATS memset(&p->se.statistics, 0, sizeof(p->se.statistics)); #endif |