Messages in this thread Patch in this message | | | Subject | [PATCH v2 5/6] sched: add exports tracking cfs bandwidth control statistics | From | Paul Turner <> | Date | Wed, 28 Apr 2010 04:17:12 -0700 |
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From: Nikhil Rao <ncrao@google.com>
This change introduces statistics exports for the cpu sub-system, these are added through the use of a stat file similar to that exported by other subsystems.
The following exports are included:
nr_periods: number of periods in which execution occurred nr_throttled: the number of periods above in which execution was throttle throttled_time: cumulative wall-time that any cpus have been throttled for this group
Signed-off-by: Paul Turner <pjt@google.com> --- kernel/sched.c | 26 ++++++++++++++++++++++++++ kernel/sched_fair.c | 19 ++++++++++++++++++- 2 files changed, 44 insertions(+), 1 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c index aca1d32..ac74d3a 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -251,6 +251,11 @@ struct cfs_bandwidth { ktime_t period; u64 runtime, quota; struct hrtimer period_timer; + + /* throttle statistics */ + u64 nr_periods; + u64 nr_throttled; + u64 throttled_time; }; #endif @@ -423,6 +428,7 @@ struct cfs_rq { #ifdef CONFIG_CFS_BANDWIDTH u64 quota_assigned, quota_used; int throttled; + u64 throttled_timestamp; #endif #endif }; @@ -460,6 +466,10 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, u64 quota, u64 period) hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cfs_b->period_timer.function = sched_cfs_period_timer; + + cfs_b->nr_periods = 0; + cfs_b->nr_throttled = 0; + cfs_b->throttled_time = 0; } static @@ -8996,6 +9006,18 @@ static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype, return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us); } +static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft, + struct cgroup_map_cb *cb) +{ + struct task_group *tg = cgroup_tg(cgrp); + struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); + + cb->fill(cb, "nr_periods", cfs_b->nr_periods); + cb->fill(cb, "nr_throttled", cfs_b->nr_throttled); + cb->fill(cb, "throttled_time", cfs_b->throttled_time); + + return 0; +} #endif /* CONFIG_CFS_BANDWIDTH */ #endif /* CONFIG_FAIR_GROUP_SCHED */ @@ -9042,6 +9064,10 @@ static struct cftype cpu_files[] = { .read_u64 = cpu_cfs_period_read_u64, .write_u64 = cpu_cfs_period_write_u64, }, + { + .name = "stat", + .read_map = cpu_stats_show, + }, #endif #ifdef CONFIG_RT_GROUP_SCHED { diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 11de5de..edea44e 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1229,15 +1229,26 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) break; } cfs_rq->throttled = 1; + cfs_rq->throttled_timestamp = rq_of(cfs_rq)->clock; } static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) { struct sched_entity *se; + struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); + struct rq *rq = rq_of(cfs_rq); se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))]; + /* update stats */ + update_rq_clock(rq); + raw_spin_lock(&cfs_b->lock); + cfs_b->throttled_time += (rq->clock - cfs_rq->throttled_timestamp); + raw_spin_unlock(&cfs_b->lock); + cfs_rq->throttled = 0; + cfs_rq->throttled_timestamp = 0; + for_each_sched_entity(se) { if (se->on_rq) break; @@ -1271,7 +1282,7 @@ static void account_cfs_rq_quota(struct cfs_rq *cfs_rq, static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) { - int i, idle = 1; + int i, idle = 1, num_throttled = 0; u64 delta; const struct cpumask *span; @@ -1293,6 +1304,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) if (!cfs_rq_throttled(cfs_rq)) continue; + num_throttled++; delta = tg_request_cfs_quota(cfs_rq->tg); @@ -1306,6 +1318,11 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) } } + /* update throttled stats */ + cfs_b->nr_periods++; + if (num_throttled) + cfs_b->nr_throttled++; + return idle; }
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