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author | Paul Turner <pjt@google.com> | 2012-10-04 11:18:30 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2012-10-24 08:27:22 (GMT) |
commit | 9ee474f55664ff63111c843099d365e7ecffb56f (patch) | |
tree | 745a678b0d3cd72ba42b67d0b6ac6c3872b14229 /kernel/sched/debug.c | |
parent | 2dac754e10a5d41d94d2d2365c0345d4f215a266 (diff) | |
download | linux-fsl-qoriq-9ee474f55664ff63111c843099d365e7ecffb56f.tar.xz |
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/debug.c')
-rw-r--r-- | kernel/sched/debug.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index c953a89..2d2e2b3 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -95,6 +95,7 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group P(se->avg.runnable_avg_sum); P(se->avg.runnable_avg_period); P(se->avg.load_avg_contrib); + P(se->avg.decay_count); #endif #undef PN #undef P @@ -227,6 +228,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) atomic_read(&cfs_rq->tg->load_weight)); SEQ_printf(m, " .%-30s: %lld\n", "runnable_load_avg", cfs_rq->runnable_load_avg); + SEQ_printf(m, " .%-30s: %lld\n", "blocked_load_avg", + cfs_rq->blocked_load_avg); #endif print_cfs_group_stats(m, cpu, cfs_rq->tg); |