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From: Tejun Heo <tj@kernel.org>
To: Benjamin Segall <bsegall@google.com>
Cc: Zhang Qiao <zhangqiao22@huawei.com>,
	mingo@redhat.com, peterz@infradead.org,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	lizefan.x@bytedance.com, hannes@cmpxchg.org,
	cgroups@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>,
	vschneid@redhat.com, dietmar.eggemann@arm.com,
	bristot@redhat.com, Steven Rostedt <rostedt@goodmis.org>,
	mgorman@suse.de
Subject: Re: [Question] The system may be stuck if there is a cpu cgroup cpu.cfs_quato_us is very low
Date: Sat, 2 Jul 2022 05:15:43 +0900	[thread overview]
Message-ID: <Yr9V755mL6jr20c2@mtj.duckdns.org> (raw)
In-Reply-To: <xm26czeoioju.fsf@google.com>

On Fri, Jul 01, 2022 at 01:08:21PM -0700, Benjamin Segall wrote:
> Yes, fixing (kernel) priority inversion due to CFS_BANDWIDTH requires a
> serious reworking of how it works, because it would need to dequeue
> tasks individually rather than doing the entire cfs_rq at a time (and
> would require some effort to avoid pinging every throttling task to get
> it into the kernel).

Right, I don't have a good idea on evolving the current implementation
into something correct. As you pointed out, we need to account along
the sched_group tree but conditionally enforce on each thread.

Thanks.

-- 
tejun

  reply	other threads:[~2022-07-01 20:15 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-27  6:50 Zhang Qiao
2022-06-27  8:32 ` Tejun Heo
2022-07-01  7:34   ` Zhang Qiao
2022-07-01 20:08     ` Benjamin Segall
2022-07-01 20:15       ` Tejun Heo [this message]
2022-07-07  6:59         ` Zhang Qiao

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