From: Roman Gushchin <guro@fb.com>
To: John Stultz <john.stultz@linaro.org>
Cc: Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.com>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: OOPSes in mem_cgroup_protected
Date: Wed, 13 Jun 2018 12:50:57 -0700 [thread overview]
Message-ID: <20180613195054.GA1647@castle.DHCP.thefacebook.com> (raw)
In-Reply-To: <CALAqxLX1F7ZwXqVm4PDmHmJhKNmox8QL4GL9S03TAhfMxOCOyw@mail.gmail.com>
On Wed, Jun 13, 2018 at 12:40:23PM -0700, John Stultz wrote:
> On Tue, Jun 12, 2018 at 9:33 PM, Roman Gushchin <guro@fb.com> wrote:
> > On Tue, Jun 12, 2018 at 09:08:27PM -0700, John Stultz wrote:
> >> On Tue, Jun 12, 2018 at 6:02 PM, John Stultz <john.stultz@linaro.org> wrote:
> >> > Hey Tejun,
> >> > With the current linus/master, I'm able to fairly regularly trip
> >> > OOPSes (two examples below) in mem_cgroup_protected(), which seems to
> >> > be new. I haven't managed to trigger this sort of thing with v4.17.
> >> >
> >> > I've not had much time to dig in or bisect it - I only know that
> >> > enabling most of the memory debuging config options didn't seem to
> >> > trip anything prior to the issue. So I wanted to send you a heads up
> >> > to see if there was already known, or if there was anything you might
> >> > suggest to help chase this down.
> >>
> >>
> >> So the line where we're crashing seems to be in mem_cgroup_protected():
> >> parent_emin = READ_ONCE(parent->memory.emin);
> >>
> >> where I'm guessing the parent->memory value is null, and emin is at
> >> the 0x120 offset in the strucutre.
> >>
> >> Reverting the following commits seems to avoid the issue.
> >> bf8d5d52ffe8 ("memcg: introduce memory.min")
> >> 5f93ad67436b ("mm: treat memory.low value inclusive")
> >> 230671533d64 ("mm: memory.low hierarchical behavior")
> >>
> >> I'm guessing I'm tripping over some path where the memory value never
> >> gets initialized?
> >>
> >> Any ideas or suggestions?
> >
> > Hi, John!
> >
> > The patch below should fix the problem.
> > It's in the mm tree right now, and hopefully will be merged upstream asap.
> > Sorry for the inconvenience.
>
> No worries, thanks for the quick fix! The patch you sent seems to be
> working well!
Perfect, thanks!
prev parent reply other threads:[~2018-06-13 19:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-13 1:02 OOPSes in mem_cgroup_protected John Stultz
2018-06-13 4:08 ` John Stultz
2018-06-13 4:33 ` Roman Gushchin
2018-06-13 19:40 ` John Stultz
2018-06-13 19:50 ` Roman Gushchin [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=20180613195054.GA1647@castle.DHCP.thefacebook.com \
--to=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mhocko@suse.com \
--cc=tj@kernel.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