From: Michal Hocko <mhocko@kernel.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>,
phillip@squashfs.org.uk, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] squashfs: enable __GFP_FS in ->readpage to prevent hang in mem alloc
Date: Mon, 17 Dec 2018 10:33:37 +0100 [thread overview]
Message-ID: <20181217093337.GC30879@dhcp22.suse.cz> (raw)
In-Reply-To: <20181217035157.GK10600@bombadil.infradead.org>
On Sun 16-12-18 19:51:57, Matthew Wilcox wrote:
[...]
> Ah, yes, that makes perfect sense. Thank you for the explanation.
>
> I wonder if the correct fix, however, is not to move the check for
> GFP_NOFS in out_of_memory() down to below the check whether to kill
> the current task. That would solve your problem, and I don't _think_
> it would cause any new ones. Michal, you touched this code last, what
> do you think?
What do you mean exactly? Whether we kill a current task or something
else doesn't change much on the fact that NOFS is a reclaim restricted
context and we might kill too early. If the fs can do GFP_FS then it is
obviously a better thing to do because FS metadata can be reclaimed as
well and therefore there is potentially less memory pressure on
application data.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-12-17 9:33 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-04 2:08 [PATCH] squashfs: enable __GFP_FS in ->readpage to prevent hang in mem alloc Hou Tao
2018-12-06 1:14 ` Hou Tao
2018-12-13 2:18 ` Hou Tao
2018-12-15 13:24 ` Hou Tao
2018-12-15 14:38 ` Matthew Wilcox
2018-12-16 9:38 ` Hou Tao
2018-12-17 3:51 ` Matthew Wilcox
2018-12-17 9:33 ` Michal Hocko [this message]
2018-12-17 10:51 ` Tetsuo Handa
2018-12-17 12:25 ` Matthew Wilcox
2018-12-17 14:10 ` Michal Hocko
2018-12-17 14:41 ` Matthew Wilcox
2018-12-17 14:49 ` Michal Hocko
2018-12-18 6:06 ` Hou Tao
2018-12-18 11:32 ` Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181217093337.GC30879@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=houtao1@huawei.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=phillip@squashfs.org.uk \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).