From: "tip-bot2 for Josh Don" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Josh Don <joshdon@google.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Jiang Biao <benbjiang@tencent.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] sched: adjust sleeper credit for SCHED_IDLE entities
Date: Thu, 09 Sep 2021 11:18:26 -0000 [thread overview]
Message-ID: <163118630675.25758.7642437893126433247.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210820010403.946838-5-joshdon@google.com>
The following commit has been merged into the sched/core branch of tip:
Commit-ID: bb1fc3bc521782d018902143c8301ab4a5e53557
Gitweb: https://git.kernel.org/tip/bb1fc3bc521782d018902143c8301ab4a5e53557
Author: Josh Don <joshdon@google.com>
AuthorDate: Thu, 19 Aug 2021 18:04:03 -07:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 09 Sep 2021 11:27:31 +02:00
sched: adjust sleeper credit for SCHED_IDLE entities
Give reduced sleeper credit to SCHED_IDLE entities. As a result, woken
SCHED_IDLE entities will take longer to preempt normal entities.
The benefit of this change is to make it less likely that a newly woken
SCHED_IDLE entity will preempt a short-running normal entity before it
blocks.
We still give a small sleeper credit to SCHED_IDLE entities, so that
idle<->idle competition retains some fairness.
Example: With HZ=1000, spawned four threads affined to one cpu, one of
which was set to SCHED_IDLE. Without this patch, wakeup latency for the
SCHED_IDLE thread was ~1-2ms, with the patch the wakeup latency was
~5ms.
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Link: https://lore.kernel.org/r/20210820010403.946838-5-joshdon@google.com
---
kernel/sched/fair.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7330a77..b27ed8b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4201,7 +4201,12 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
/* sleeps up to a single latency don't count. */
if (!initial) {
- unsigned long thresh = sysctl_sched_latency;
+ unsigned long thresh;
+
+ if (se_is_idle(se))
+ thresh = sysctl_sched_min_granularity;
+ else
+ thresh = sysctl_sched_latency;
/*
* Halve their sleep time's effect, to allow
next prev parent reply other threads:[~2021-09-09 11:18 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 1:03 [PATCH v3 0/4] SCHED_IDLE extensions Josh Don
2021-08-20 1:04 ` [PATCH v3 2/4] sched: account number of SCHED_IDLE entities on each cfs_rq Josh Don
2021-08-24 7:57 ` Vincent Guittot
2021-09-09 11:18 ` [tip: sched/core] sched: Account " tip-bot2 for Josh Don
2021-10-05 14:12 ` tip-bot2 for Josh Don
2021-08-20 1:04 ` [PATCH v3 3/4] sched: reduce sched slice for SCHED_IDLE entities Josh Don
2021-08-23 10:08 ` Vincent Guittot
2021-08-23 17:40 ` Josh Don
2021-08-24 7:56 ` Vincent Guittot
2021-08-24 10:24 ` Jiang Biao
2021-08-24 17:04 ` Josh Don
2021-08-25 2:43 ` Jiang Biao
2021-09-09 11:18 ` [tip: sched/core] " tip-bot2 for Josh Don
2021-10-05 14:12 ` tip-bot2 for Josh Don
2021-08-20 1:04 ` [PATCH v3 4/4] sched: adjust sleeper credit " Josh Don
2021-08-23 10:09 ` Vincent Guittot
2021-08-24 8:16 ` Jiang Biao
2021-08-24 17:12 ` Josh Don
2021-09-09 11:18 ` tip-bot2 for Josh Don [this message]
2021-10-05 14:12 ` [tip: sched/core] " tip-bot2 for Josh Don
[not found] ` <20210906124702.Q6G0oOWwFOmQSl_jmRms3XQgfz4ROzfE71r3SNgWSf0@z>
2021-09-06 12:47 ` [PATCH v3 1/4] sched: cgroup SCHED_IDLE support alexs
2021-08-20 8:39 ` Tao Zhou
2021-08-23 17:29 ` Josh Don
2021-08-23 22:45 ` Tao Zhou
2021-09-02 1:22 ` Daniel Jordan
2021-09-03 1:21 ` Josh Don
2021-09-08 20:38 ` Daniel Jordan
2021-09-08 18:36 ` Josh Don
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=163118630675.25758.7642437893126433247.tip-bot2@tip-bot2 \
--to=tip-bot2@linutronix.de \
--cc=benbjiang@tencent.com \
--cc=joshdon@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=vincent.guittot@linaro.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).