From: Huaixin Chang <changhuaixin@linux.alibaba.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, anderson@cs.unc.edu, baruah@wustl.edu,
bsegall@google.com, changhuaixin@linux.alibaba.com,
dietmar.eggemann@arm.com, dtcccc@linux.alibaba.com,
juri.lelli@redhat.com, khlebnikov@yandex-team.ru,
luca.abeni@santannapisa.it, mgorman@suse.de, mingo@redhat.com,
odin@uged.al, odin@ugedal.com, pauld@redhead.com, pjt@google.com,
rostedt@goodmis.org, shanpeic@linux.alibaba.com, tj@kernel.org,
tommaso.cucinotta@santannapisa.it, vincent.guittot@linaro.org,
xiyou.wangcong@gmail.com, daniel.m.jordan@oracle.com
Subject: [PATCH 1/2] sched/fair: Add cfs bandwidth burst statistics
Date: Mon, 30 Aug 2021 11:22:14 +0800 [thread overview]
Message-ID: <20210830032215.16302-2-changhuaixin@linux.alibaba.com> (raw)
In-Reply-To: <20210830032215.16302-1-changhuaixin@linux.alibaba.com>
Two new statistics are introduced to show the internal of burst feature
and explain why burst helps or not.
nr_bursts: number of periods bandwidth burst occurs
burst_time: cumulative wall-time (in nanoseconds) that any cpus has
used above quota in respective periods
Co-developed-by: Shanpei Chen <shanpeic@linux.alibaba.com>
Signed-off-by: Shanpei Chen <shanpeic@linux.alibaba.com>
Co-developed-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com>
---
kernel/sched/core.c | 13 ++++++++++---
kernel/sched/fair.c | 9 +++++++++
kernel/sched/sched.h | 3 +++
3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 20ffcc044134..d00b92712253 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -10068,6 +10068,9 @@ static int cpu_cfs_stat_show(struct seq_file *sf, void *v)
seq_printf(sf, "wait_sum %llu\n", ws);
}
+ seq_printf(sf, "nr_bursts %d\n", cfs_b->nr_burst);
+ seq_printf(sf, "burst_time %llu\n", cfs_b->burst_time);
+
return 0;
}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -10164,16 +10167,20 @@ static int cpu_extra_stat_show(struct seq_file *sf,
{
struct task_group *tg = css_tg(css);
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
- u64 throttled_usec;
+ u64 throttled_usec, burst_usec;
throttled_usec = cfs_b->throttled_time;
do_div(throttled_usec, NSEC_PER_USEC);
+ burst_usec = cfs_b->burst_time;
+ do_div(burst_usec, NSEC_PER_USEC);
seq_printf(sf, "nr_periods %d\n"
"nr_throttled %d\n"
- "throttled_usec %llu\n",
+ "throttled_usec %llu\n"
+ "nr_bursts %d\n"
+ "burst_usec %llu\n",
cfs_b->nr_periods, cfs_b->nr_throttled,
- throttled_usec);
+ throttled_usec, cfs_b->nr_burst, burst_usec);
}
#endif
return 0;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 44c452072a1b..464371f364f1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4655,11 +4655,20 @@ static inline u64 sched_cfs_bandwidth_slice(void)
*/
void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
{
+ s64 runtime;
+
if (unlikely(cfs_b->quota == RUNTIME_INF))
return;
cfs_b->runtime += cfs_b->quota;
+ runtime = cfs_b->runtime_snap - cfs_b->runtime;
+ if (runtime > 0) {
+ cfs_b->burst_time += runtime;
+ cfs_b->nr_burst++;
+ }
+
cfs_b->runtime = min(cfs_b->runtime, cfs_b->quota + cfs_b->burst);
+ cfs_b->runtime_snap = cfs_b->runtime;
}
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 14a41a243f7b..80e4322727b4 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -367,6 +367,7 @@ struct cfs_bandwidth {
u64 quota;
u64 runtime;
u64 burst;
+ u64 runtime_snap;
s64 hierarchical_quota;
u8 idle;
@@ -379,7 +380,9 @@ struct cfs_bandwidth {
/* Statistics: */
int nr_periods;
int nr_throttled;
+ int nr_burst;
u64 throttled_time;
+ u64 burst_time;
#endif
};
--
2.14.4.44.g2045bb6
next prev parent reply other threads:[~2021-08-30 3:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 3:22 [PATCH 0/2 v2] Add statistics and document for cfs_b burst Huaixin Chang
2021-08-30 3:22 ` Huaixin Chang [this message]
2021-09-03 18:47 ` [PATCH 1/2] sched/fair: Add cfs bandwidth burst statistics Benjamin Segall
2021-09-09 11:18 ` [tip: sched/core] " tip-bot2 for Huaixin Chang
2021-10-05 14:12 ` tip-bot2 for Huaixin Chang
2021-08-30 3:22 ` [PATCH 2/2] sched/fair: Add document for burstable CFS bandwidth Huaixin Chang
2021-09-09 11:18 ` [tip: sched/core] " tip-bot2 for Huaixin Chang
2021-10-05 14:12 ` tip-bot2 for Huaixin Chang
2021-08-30 16:49 ` [PATCH 0/2 v2] Add statistics and document for cfs_b burst Tejun Heo
2021-09-01 15:37 ` Daniel Jordan
2021-09-03 13:12 ` changhuaixin
-- strict thread matches above, loose matches on Subject: below --
2021-08-16 7:08 [PATCH 0/2] Add statistics and document for cfs bandwidth burst Huaixin Chang
2021-08-16 7:08 ` [PATCH 1/2] sched/fair: Add cfs bandwidth burst statistics Huaixin Chang
2021-08-23 18:32 ` Daniel Jordan
2021-08-23 19:03 ` Tejun Heo
2021-07-30 7:09 [PATCH 0/2] Add statistics and ducument for cfs bandwidth burst Huaixin Chang
2021-07-30 7:09 ` [PATCH 1/2] sched/fair: Add cfs bandwidth burst statistics Huaixin Chang
2021-08-12 12:18 ` changhuaixin
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