From: Andrew Morton <akpm@linux-foundation.org>
To: "David Hildenbrand (Arm)" <david@kernel.org>
Cc: xueyuan.chen@vivo.com, Lorenzo Stoakes <ljs@kernel.org>,
linux-mm@kvack.org, Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
"Liam R. Howlett" <liam@infradead.org>,
Nico Pache <npache@redhat.com>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Usama Arif <usama.arif@linux.dev>,
Kiryl Shutsemau <kas@kernel.org>, Bob Liu <lliubbo@gmail.com>,
linux-kernel@vger.kernel.org,
Xueyuan Chen <xueyuan.chen21@gmail.com>
Subject: Re: [PATCH] mm/huge_memory: fix huge zero folio publication race
Date: Wed, 29 Jul 2026 18:02:41 -0700 [thread overview]
Message-ID: <20260729180241.2b8bcb2379b975b22c48d251@linux-foundation.org> (raw)
In-Reply-To: <37c40d62-51e2-45b4-9837-a4b96d1640b3@kernel.org>
On Wed, 29 Jul 2026 08:44:12 +0200 "David Hildenbrand (Arm)" <david@kernel.org> wrote:
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -245,8 +245,11 @@ static bool get_huge_zero_folio(void)
> > }
> > WRITE_ONCE(huge_zero_pfn, folio_pfn(zero_folio));
> >
> > - /* We take additional reference here. It will be put back by shrinker */
> > - atomic_set(&huge_zero_refcount, 2);
> > + /*
> > + * Publish the folio and PFN before making them available to lockless
> > + * users. Pairs with a successful atomic_inc_not_zero() above.
> > + */
> > + atomic_set_release(&huge_zero_refcount, 2);
> > preempt_enable();
> > count_vm_event(THP_ZERO_PAGE_ALLOC);
> > return true;
>
> https://lore.kernel.org/r/20260728-fix-refcounted-huge-zero-v1-0-3f261f5447b4@kernel.org
Does that actually fix the same thing?
Is so, Xueyuan's Fixes: is 97ae17497e99 ("thp: implement refcounting
for huge zero page"). Which to believe?
next prev parent reply other threads:[~2026-07-30 1:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-29 4:50 [PATCH] mm/huge_memory: fix huge zero folio publication race xueyuan.chen
2026-07-29 6:44 ` David Hildenbrand (Arm)
2026-07-30 1:02 ` Andrew Morton [this message]
2026-07-30 7:27 ` Lorenzo Stoakes (ARM)
2026-07-30 13:40 ` Xueyuan Chen
2026-07-30 14:02 ` Lorenzo Stoakes (ARM)
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