From: Peter Zijlstra <peterz@infradead.org>
To: bsegall@google.com
Cc: Huaixin Chang <changhuaixin@linux.alibaba.com>,
chiluk+linux@indeed.com, linux-kernel@vger.kernel.org,
mingo@redhat.com, pauld@redhead.com, vincent.guittot@linaro.org
Subject: Re: [PATCH v2] sched: Defend cfs and rt bandwidth quota against overflow
Date: Mon, 11 May 2020 15:03:27 +0200 [thread overview]
Message-ID: <20200511130327.GA2978@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <xm26ftcolr3p.fsf@google.com>
On Mon, Apr 27, 2020 at 11:29:30AM -0700, bsegall@google.com wrote:
> Huaixin Chang <changhuaixin@linux.alibaba.com> writes:
>
> > When users write some huge number into cpu.cfs_quota_us or
> > cpu.rt_runtime_us, overflow might happen during to_ratio() shifts of
> > schedulable checks.
> >
> > to_ratio() could be altered to avoid unnecessary internal overflow, but
> > min_cfs_quota_period is less than 1 << BW_SHIFT, so a cutoff would still
> > be needed. Set a cap MAX_BW for cfs_quota_us and rt_runtime_us to
> > prevent overflow.
>
> Reviewed-by: Ben Segall <bsegall@google.com>
Thanks!
next prev parent reply other threads:[~2020-05-11 13:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-20 2:44 [PATCH 0/2] Two small fixes for bandwidth controller Huaixin Chang
2020-04-20 2:44 ` [PATCH 1/2] sched: Defend cfs and rt bandwidth quota against overflow Huaixin Chang
2020-04-20 17:50 ` bsegall
2020-04-22 3:36 ` changhuaixin
2020-04-22 18:44 ` bsegall
2020-04-23 13:37 ` [PATCH] " Huaixin Chang
2020-04-23 20:33 ` bsegall
2020-04-25 10:52 ` [PATCH v2] " Huaixin Chang
2020-04-27 18:29 ` bsegall
2020-05-11 13:03 ` Peter Zijlstra [this message]
2020-05-19 18:44 ` [tip: sched/core] " tip-bot2 for Huaixin Chang
2020-04-22 8:38 ` [PATCH 1/2] " kbuild test robot
2020-04-24 6:35 ` kbuild test robot
2020-04-20 2:44 ` [PATCH 2/2] sched/fair: Refill bandwidth before scaling Huaixin Chang
2020-04-20 17:54 ` bsegall
2020-04-21 15:09 ` Phil Auld
2020-05-01 18:22 ` [tip: sched/core] " tip-bot2 for Huaixin Chang
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