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From: Daniel Jordan <daniel.m.jordan@oracle.com>
To: Hao Lee <haolee.swjtu@gmail.com>
Cc: linux-mm@kvack.org, cgroups@vger.kernel.org,
	linux-kernel@vger.kernel.org, tj@kernel.org
Subject: Re: [Question] Do we need remote charging for cpu and cpuacct subsys?
Date: Fri, 9 Jul 2021 11:17:56 -0400	[thread overview]
Message-ID: <20210709151756.u3su4vleiowd5tky@oracle.com> (raw)
In-Reply-To: <CA+PpKPmN2E5zCjP3mkurNA2GANtLCUmoPG+_4mUq3E8cxOhuhQ@mail.gmail.com>

Hi,

[only replying now b/c I was out most of this week]

On Sun, Jul 04, 2021 at 12:18:22AM +0800, Hao Lee wrote:
> On Sat, Jul 3, 2021 at 4:07 AM Daniel Jordan <daniel.m.jordan@oracle.com> wrote:
> > So naturally, I'm curious about your use case and how it may be
> > different from these others. What kworkers would you like to account?
> 
> Thanks. We use a workqueue to perform asynchronous reclaim for cgroups.
> The kworker may consume lots of CPU cycles if the cgroup memory pressure
> is extremely high, so we want to charge the cpu usage to the related
> cgroup for which the kworker works. Otherwise, the reclaim kworker will
> steal cpu time from the system level, which breaks the resource isolation.

Ok, that helps.

> I also have a question here. Are the back-charging and remote charging
> the same thing?

Basically yes.

> > The only one I'm aware of
> > that's like that is net rx, where the work to process packets has to
> > start before their ultimate destination, and therefore cgroup, is known.
> 
> Sorry. Is this a typo?  It seems the word "known" should be "unknown"...

What I'm saying is, the work to process packets starts when the cgroup
is unknown.


  reply	other threads:[~2021-07-09 15:18 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-02  8:26 Hao Lee
2021-07-02 20:07 ` Daniel Jordan
2021-07-02 20:19   ` Daniel Jordan
2021-07-03 16:18   ` Hao Lee
2021-07-09 15:17     ` Daniel Jordan [this message]
2021-07-02 22:26 ` Tejun Heo
2021-07-03 16:20   ` Hao Lee

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