From: Andrew Morton <akpm@linux-foundation.org>
To: Ge Yang <yangge1116@126.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
21cnbao@gmail.com, david@redhat.com,
baolin.wang@linux.alibaba.com, muchun.song@linux.dev,
osalvador@suse.de, liuzixing@hygon.cn
Subject: Re: [PATCH V2] mm/hugetlb: remove unnecessary holding of hugetlb_lock
Date: Thu, 5 Jun 2025 18:12:42 -0700 [thread overview]
Message-ID: <20250605181242.54767f38223f9ebd4c379ccb@linux-foundation.org> (raw)
In-Reply-To: <c15bfa20-2113-4299-98bf-1865b6b535ef@126.com>
On Thu, 5 Jun 2025 08:44:09 +0800 Ge Yang <yangge1116@126.com> wrote:
> > This change addresses a possible performance issue which was introduced
> > by 113ed54ad276 ("mm/hugetlb: fix kernel NULL pointer dereference when
> > replacing free hugetlb folios"). 113ed54ad276 was added recently and
> > was cc:stable.
> >
> > David said:
> > https://lkml.kernel.org/r/87521d93-cc03-480d-a2ef-3ef8c84481c9@redhat.com
> >
> >
> > Question is, will that bugfix's performance impact be sufficiently
> > serious for us to also backport this new patch?
>
> In some low-probability scenarios, there could be severe impacts. For
> example, when multiple CPUs execute the replace_free_hugepage_folios()
> function simultaneously. It seems that we need to backport this new
> patch. Thank you.
OK, thanks. I added
Fixes: 113ed54ad276 ("mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios")
Cc: <stable@vger.kernel.org>
and moved this to the mm-hotfixes pile. I'll keep it there for a week
or two for review/test. Once it goes upstream, this should propagate
into 6.15.x.
next prev parent reply other threads:[~2025-06-06 1:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-27 3:36 yangge1116
2025-05-28 2:45 ` Muchun Song
2025-06-04 22:47 ` Andrew Morton
2025-06-05 0:44 ` Ge Yang
2025-06-06 1:12 ` Andrew Morton [this message]
2025-06-06 5:45 ` Ge Yang
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