From: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com>
To: "willy@infradead.org" <willy@infradead.org>
Cc: "hch@lst.de" <hch@lst.de>, "rdna@fb.com" <rdna@fb.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>
Subject: Re: cat /proc/sys/kernel/tainted => page allocation failure: order:6
Date: Mon, 10 May 2021 12:43:58 +0000 [thread overview]
Message-ID: <1656f09a4dc88517a7cedb5c66c423f34b65266a.camel@nokia.com> (raw)
In-Reply-To: <YJkk2qnNwj60wzSo@casper.infradead.org>
On Mon, 2021-05-10 at 13:19 +0100, Matthew Wilcox wrote:
> On Mon, May 10, 2021 at 11:12:21AM +0000, Rantala, Tommi T. (Nokia -
> FI/Espoo) wrote:
> > Why is order 6 allocation required for "cat /proc/sys/kernel/tainted"
> > ...?
> > I'm seeing (occasional) failures in one VM (with 65d uptime):
> >
> > [5674989.634561] cat: page allocation failure: order:6,
> > mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO),
> > nodemask=(null),cpuset=user.slice,mems_allowed=0
> > [5674989.645432] CPU: 0 PID: 2717524 Comm: cat Not tainted 5.10.19-
> > 200.fc33.x86_64 #1
>
> The underlying problem is that 'cat' is asking to do a 128kB read (!)
> so we allocate 256kB (!) of contiguous (!) memory. This is already
> mostly fixed upstream. Please upgrade your kernel.
Ahh, thanks!
Indeed I missed "proc: use kvzalloc for our kernel buffer"
-Tommi
prev parent reply other threads:[~2021-05-10 13:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 11:12 cat /proc/sys/kernel/tainted => page allocation failure: order:6 Rantala, Tommi T. (Nokia - FI/Espoo)
2021-05-10 12:19 ` Matthew Wilcox
2021-05-10 12:43 ` Rantala, Tommi T. (Nokia - FI/Espoo) [this message]
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=1656f09a4dc88517a7cedb5c66c423f34b65266a.camel@nokia.com \
--to=tommi.t.rantala@nokia.com \
--cc=hch@lst.de \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rdna@fb.com \
--cc=viro@zeniv.linux.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).