From: Andrew Morton <akpm@linux-foundation.org>
To: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Pavan Kondeti <quic_pkondeti@quicinc.com>, <osalvador@suse.de>,
<dan.j.williams@intel.com>, <david@redhat.com>, <vbabka@suse.cz>,
<mgorman@techsingularity.net>, <aneesh.kumar@linux.ibm.com>,
<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm/sparsemem: fix race in accessing memory_section->usage
Date: Wed, 25 Oct 2023 14:35:41 -0700 [thread overview]
Message-ID: <20231025143541.e7cf114239b84105711a5f70@linux-foundation.org> (raw)
In-Reply-To: <b4a2bbe8-4181-68ad-1a6c-463fbe64d8f8@quicinc.com>
On Tue, 17 Oct 2023 19:40:15 +0530 Charan Teja Kalla <quic_charante@quicinc.com> wrote:
> >> * was allocated during boot.
> >> */
> >> if (!PageReserved(virt_to_page(ms->usage))) {
> >> + synchronize_rcu();
> >> kfree(ms->usage);
> >> ms->usage = NULL;
> >> }
> > If we add NULL checks around ms->usage, this becomes
> >
> > tmp = rcu_replace_pointer(ms->usage, NULL, hotplug_locked());
> > syncrhonize_rcu();
> > kfree(tmp);
> Per David input, I am working on using kfree_rcu().
How's it coming along?
Given that we're at 6.6-rc7 and given that this issue is causing
daily crashes in your device farm, I'm thinking that we use the current
version of your patch for 6.6 and for -stable. We can look at the
kfree_rcu() optimization for later kernel releases?
next prev parent reply other threads:[~2023-10-25 21:35 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-13 13:04 Charan Teja Kalla
2023-10-14 22:25 ` Andrew Morton
2023-10-16 8:23 ` David Hildenbrand
2023-10-16 13:38 ` Charan Teja Kalla
2023-10-16 22:34 ` Andrew Morton
2023-10-18 7:52 ` David Hildenbrand
2023-10-16 10:33 ` Pavan Kondeti
2023-10-17 14:10 ` Charan Teja Kalla
2023-10-17 14:53 ` David Hildenbrand
2023-10-25 21:35 ` Andrew Morton [this message]
2023-10-26 7:00 ` David Hildenbrand
2023-10-26 7:18 ` Charan Teja Kalla
2024-01-15 18:44 ` Alexander Potapenko
2024-01-15 20:34 ` Marco Elver
2024-01-17 19:18 ` Marco Elver
2024-01-18 9:01 ` Alexander Potapenko
2024-01-18 9:43 ` Marco Elver
2024-01-25 13:20 ` Paul E. McKenney
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=20231025143541.e7cf114239b84105711a5f70@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=osalvador@suse.de \
--cc=quic_charante@quicinc.com \
--cc=quic_pkondeti@quicinc.com \
--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