From: Peter Zijlstra <peterz@infradead.org>
To: Honglei Wang <wanghonglei@didichuxing.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
linux-kernel@vger.kernel.org,
Huaixin Chang <changhuaixin@linux.alibaba.com>,
Honglei Wang <jameshongleiwang@126.com>
Subject: Re: [PATCH v2 1/3] sched/fair: avoid burst statistic if it's not set
Date: Thu, 9 Dec 2021 13:22:08 +0100 [thread overview]
Message-ID: <YbH08Nw3WpyxElE9@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20211208145018.64657-1-wanghonglei@didichuxing.com>
On Wed, Dec 08, 2021 at 10:50:18PM +0800, Honglei Wang wrote:
> It's not necessary to do burst associated statistic and calculation for
> runtime if the burst feature is not set at all. Just return at the very
> start point if so.
>
> Signed-off-by: Honglei Wang <wanghonglei@didichuxing.com>
> ---
> kernel/sched/fair.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 6e476f6d9435..2cd626c22912 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4640,6 +4640,11 @@ void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
> if (unlikely(cfs_b->quota == RUNTIME_INF))
> return;
>
> + if (cfs_b->burst == 0 && cfs_b->runtime_snap == cfs_b->quota) {
> + cfs_b->runtime = cfs_b->quota;
> + return;
> + }
> +
> cfs_b->runtime += cfs_b->quota;
> runtime = cfs_b->runtime_snap - cfs_b->runtime;
> if (runtime > 0) {
What actual purpose does this patch serve, other than to increase the
line-count?
next prev parent reply other threads:[~2021-12-09 12:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-08 14:50 [PATCH v2 1/3] sched/fair: avoid burst statistic if it's not set Honglei Wang
2021-12-09 12:22 ` Peter Zijlstra [this message]
2021-12-09 15:24 ` Honglei Wang
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