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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-10-15 17:00:10 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-15 17:00:10 +0200 |
| commit | ddc972975091ba5f839bf24d0f9ef54fe90ee741 (patch) | |
| tree | 438406a2930bdcb36c8a1bc6778aab49e1fba36d /kernel/sched_fair.c | |
| parent | d822cecedad88b69a7d68aa8d49e1f238aa320c7 (diff) | |
| download | lwn-ddc972975091ba5f839bf24d0f9ef54fe90ee741.tar.gz lwn-ddc972975091ba5f839bf24d0f9ef54fe90ee741.zip | |
sched debug: check spread
debug feature: check how well we schedule within a reasonable
vruntime 'spread' range. (note that CPU overload can increase
the spread, so this is not a hard condition, but normal loads
should be within the spread.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 87acc5cedd2d..8ea4c9b3e411 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -447,6 +447,19 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) #endif } +static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ +#ifdef CONFIG_SCHED_DEBUG + s64 d = se->vruntime - cfs_rq->min_vruntime; + + if (d < 0) + d = -d; + + if (d > 3*sysctl_sched_latency) + schedstat_inc(cfs_rq, nr_spread_over); +#endif +} + static void place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) { @@ -494,6 +507,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) } update_stats_enqueue(cfs_rq, se); + check_spread(cfs_rq, se); if (se != cfs_rq->curr) __enqueue_entity(cfs_rq, se); account_entity_enqueue(cfs_rq, se); @@ -587,6 +601,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) update_stats_curr_end(cfs_rq, prev); + check_spread(cfs_rq, prev); if (prev->on_rq) { update_stats_wait_start(cfs_rq, prev); /* Put 'current' back into the tree. */ @@ -996,6 +1011,8 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) } update_stats_enqueue(cfs_rq, se); + check_spread(cfs_rq, se); + check_spread(cfs_rq, curr); __enqueue_entity(cfs_rq, se); account_entity_enqueue(cfs_rq, se); resched_task(rq->curr); |