From: Pedro Falcato <pfalcato@suse.de>
To: "Lorenzo Stoakes (Oracle)" <ljs@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>, Jann Horn <jannh@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Jianzhou Zhao <luckd0g@163.com>,
Oscar Salvador <osalvador@suse.de>
Subject: Re: [PATCH 2/3] mm: abstract reading sysctl_max_map_count, and READ_ONCE()
Date: Fri, 27 Mar 2026 09:20:17 +0000 [thread overview]
Message-ID: <357u5es4z7jjnpkyefubvlygpkcinqomnyg233ra6geeamq35y@fuor6y4es3cp> (raw)
In-Reply-To: <0715259eb37cbdfde4f9e5db92a20ec7110a1ce5.1773249037.git.ljs@kernel.org>
On Wed, Mar 11, 2026 at 05:24:37PM +0000, Lorenzo Stoakes (Oracle) wrote:
> Concurrent reads and writes of sysctl_max_map_count are possible, so we
> should READ_ONCE() and WRITE_ONCE().
>
> The sysctl procfs logic already enforces WRITE_ONCE(), so abstract the read
> side with get_sysctl_max_map_count().
>
> While we're here, also move the field to mm/internal.h and add the getter
> there since only mm interacts with it, there's no need for anybody else to
> have access.
>
> Finally, update the VMA userland tests to reflect the change.
>
> Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
--
Pedro
next prev parent reply other threads:[~2026-03-27 9:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-11 17:24 [PATCH 0/3] mm: improve map count checks Lorenzo Stoakes (Oracle)
2026-03-11 17:24 ` [PATCH 1/3] mm/mremap: correct invalid map count check Lorenzo Stoakes (Oracle)
2026-03-27 9:19 ` Pedro Falcato
2026-03-11 17:24 ` [PATCH 2/3] mm: abstract reading sysctl_max_map_count, and READ_ONCE() Lorenzo Stoakes (Oracle)
2026-03-27 9:20 ` Pedro Falcato [this message]
2026-03-11 17:24 ` [PATCH 3/3] mm/mremap: check map count under mmap write lock and abstract Lorenzo Stoakes (Oracle)
2026-03-27 9:22 ` Pedro Falcato
2026-03-27 9:58 ` Lorenzo Stoakes (Oracle)
2026-03-27 5:42 ` [PATCH 0/3] mm: improve map count checks Andrew Morton
2026-03-27 9:23 ` Pedro Falcato
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