linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Klara Modin <klarasmodin@gmail.com>
To: JP Kobryn <inwardvessel@gmail.com>
Cc: tj@kernel.org, shakeel.butt@linux.dev, yosryahmed@google.com,
	 mkoutny@suse.com, hannes@cmpxchg.org, akpm@linux-foundation.org,
	 linux-mm@kvack.org, cgroups@vger.kernel.org,
	kernel-team@meta.com
Subject: Re: [PATCH cgroup/for-6.16] cgroup: avoid per-cpu allocation of size zero rstat cpu locks
Date: Thu, 22 May 2025 15:22:21 +0200	[thread overview]
Message-ID: <xmvzgfhmfujzxm7xa7lthl75z3gpvmei5fqyzjzdrjzveam7hu@ad6yhbpl27sk> (raw)
In-Reply-To: <20250522013202.185523-1-inwardvessel@gmail.com>

On 2025-05-21 18:32:02 -0700, JP Kobryn wrote:
> Subsystem rstat locks are dynamically allocated per-cpu. It was discovered
> that a panic can occur during this allocation when the lock size is zero.
> This is the case on non-smp systems, since arch_spinlock_t is defined as an
> empty struct. Prevent this allocation when !CONFIG_SMP by adding a
> pre-processor conditional around the affected block.
> 
> Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
> Reported-by: Klara Modin <klarasmodin@gmail.com>
> Fixes: 748922dcfabd ("cgroup: use subsystem-specific rstat locks to avoid contention")

I can confirm this resolves the issue for me.

Thanks,
Tested-by: Klara Modin <klarasmodin@gmail.com>


  parent reply	other threads:[~2025-05-22 13:22 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-22  1:32 JP Kobryn
2025-05-22  1:55 ` Tejun Heo
2025-05-22 13:22 ` Klara Modin [this message]
2025-06-03  3:38 ` Guenter Roeck
2025-06-03  4:10   ` Shakeel Butt
2025-06-03  4:26     ` Guenter Roeck

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=xmvzgfhmfujzxm7xa7lthl75z3gpvmei5fqyzjzdrjzveam7hu@ad6yhbpl27sk \
    --to=klarasmodin@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=cgroups@vger.kernel.org \
    --cc=hannes@cmpxchg.org \
    --cc=inwardvessel@gmail.com \
    --cc=kernel-team@meta.com \
    --cc=linux-mm@kvack.org \
    --cc=mkoutny@suse.com \
    --cc=shakeel.butt@linux.dev \
    --cc=tj@kernel.org \
    --cc=yosryahmed@google.com \
    /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