From: Shakeel Butt <shakeelb@google.com>
To: Roman Gushchin <guro@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux MM <linux-mm@kvack.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Kernel Team <kernel-team@fb.com>,
LKML <linux-kernel@vger.kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
stable@vger.kernel.org
Subject: Re: [PATCH] mm: memcg/slab: fix racy access to page->mem_cgroup in mem_cgroup_from_obj()
Date: Fri, 11 Sep 2020 15:40:20 -0700 [thread overview]
Message-ID: <CALvZod7+-DFfN7cpb8W7O2jHEgU1BSmPyW+-hfmTTUKUi4QG1A@mail.gmail.com> (raw)
In-Reply-To: <20200911213402.GB1163084@carbon.dhcp.thefacebook.com>
On Fri, Sep 11, 2020 at 2:34 PM Roman Gushchin <guro@fb.com> wrote:
>
[snip]
> >
> > Also have you taken a look at [1]? I am still trying to figure out how
> > that is possible.
> >
> > [1] https://lore.kernel.org/lkml/20200901075321.GL4299@shao2-debian/
>
> Hm, yeah, it's complicated. At the very first glance it looks like that the
> obj_cgroups vector is placed onto the very same page it describes, or at least
> it shares the kmem_cache with it, with some bad consequences. Could be something
> SLAB-specific, newer saw anything like that with SLUB.
> Or maybe it's completely unrelated and has been attributed to this commit
> by mistake.
>
> I've spent several hours running the provided test in a loop, but wasn't
> lucky enough to trigger it. Did you try?
>
Yeah same, no success in reproducing it.
next prev parent reply other threads:[~2020-09-11 22:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 2:24 Roman Gushchin
2020-09-10 22:43 ` Roman Gushchin
2020-09-11 16:21 ` Shakeel Butt
2020-09-11 21:34 ` Roman Gushchin
2020-09-11 22:40 ` Shakeel Butt [this message]
2020-09-11 22:41 ` Shakeel Butt
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=CALvZod7+-DFfN7cpb8W7O2jHEgU1BSmPyW+-hfmTTUKUi4QG1A@mail.gmail.com \
--to=shakeelb@google.com \
--cc=akpm@linux-foundation.org \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=stable@vger.kernel.org \
--cc=vbabka@suse.cz \
/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
all inboxes | Powered by JetHome®