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From: Greg KH <greg@kroah.com>
To: wuzhouhui <wuzhouhui14@mails.ucas.ac.cn>
Cc: kernelnewbies@kernelnewbies.org
Subject: Re: How to avoid or reduce GFP_ATOMIC allocation failed
Date: Fri, 8 Mar 2019 08:21:52 +0100	[thread overview]
Message-ID: <20190308072152.GA10654@kroah.com> (raw)
In-Reply-To: <51af9230.9ed2.1695bce6545.Coremail.wuzhouhui14@mails.ucas.ac.cn>

On Fri, Mar 08, 2019 at 01:37:26PM +0800, wuzhouhui wrote:
> Hi,
> 
> I check kernel code and found that GFP_ATOMIC allocation will
> use emergency pool and maybe failed if emergency pool is not
> enough. And GFP_ATOMIC doesn't trigger reclaim (because of
> ATOMIC) even if there are a lot of page caches. So my question
> is how to avoid or reduce GFP_ATOMIC allocation failed if there
> are enough reclaimable memory? Is there some kernel parameters
> can be configured?

Have you seen the ATOMIC pools be used up and not able to be reclaimed
in real-world usages?  If so, I'm sure the mm developers would love to
hear from you about this as I really do not think that is a situation
that can happen easily, if at all.

And no, I do not think there are any such parameters, the kernel should
be self-tuning for things like this.

thanks,

greg k-h

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  reply	other threads:[~2019-03-08  7:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-08  5:37 How to avoid or reduce GFP_ATOMIC allocation failed wuzhouhui
2019-03-08  7:21 ` Greg KH [this message]
2019-03-08  7:34   ` wuzhouhui
2019-03-08  7:40     ` greg kh

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