From: "Christoph Lameter (Ampere)" <cl@gentwo.org>
To: Harry Yoo <harry.yoo@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Mateusz Guzik <mjguzik@gmail.com>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Cong Wang <xiyou.wangcong@gmail.com>,
Jiri Pirko <jiri@resnulli.us>, Vlad Buslov <vladbu@nvidia.com>,
Yevgeny Kliteynik <kliteyn@nvidia.com>, Jan Kara <jack@suse.cz>,
Byungchul Park <byungchul@sk.com>,
linux-mm@kvack.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 0/7] Reviving the slab destructor to tackle the percpu allocator scalability problem
Date: Thu, 24 Apr 2025 08:50:04 -0700 (PDT) [thread overview]
Message-ID: <80208a6c-ec42-6260-5f6f-b3c5c2788fcd@gentwo.org> (raw)
In-Reply-To: <20250424080755.272925-1-harry.yoo@oracle.com>
[-- Attachment #1: Type: text/plain, Size: 568 bytes --]
On Thu, 24 Apr 2025, Harry Yoo wrote:
> Consider mm_struct: it allocates two percpu regions (mm_cid and rss_stat),
> so each allocate–free cycle requires two expensive acquire/release on
> that mutex.
> We can mitigate this contention by retaining the percpu regions after
> the object is freed and releasing them only when the backing slab pages
> are freed.
Could you keep a cache of recently used per cpu regions so that you can
avoid frequent percpu allocation operation?
You could allocate larger percpu areas for a batch of them and
then assign as needed.
next prev parent reply other threads:[~2025-04-24 15:50 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-24 8:07 Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 1/7] mm/slab: refactor freelist shuffle Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 2/7] treewide, slab: allow slab constructor to return an error Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 3/7] mm/slab: revive the destructor feature in slab allocator Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 4/7] net/sched/act_api: use slab ctor/dtor to reduce contention on pcpu alloc Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 5/7] mm/percpu: allow (un)charging objects without alloc/free Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 6/7] lib/percpu_counter: allow (un)charging percpu counters " Harry Yoo
2025-04-24 8:07 ` [RFC PATCH 7/7] kernel/fork: improve exec() throughput with slab ctor/dtor pair Harry Yoo
2025-04-24 9:29 ` [RFC PATCH 0/7] Reviving the slab destructor to tackle the percpu allocator scalability problem Mateusz Guzik
2025-04-24 9:58 ` Harry Yoo
2025-04-24 15:00 ` Mateusz Guzik
2025-04-24 11:28 ` Pedro Falcato
2025-04-24 15:20 ` Mateusz Guzik
2025-04-24 16:11 ` Mateusz Guzik
2025-04-25 7:40 ` Harry Yoo
2025-04-25 10:12 ` Harry Yoo
2025-04-25 10:42 ` Pedro Falcato
2025-04-28 1:18 ` Harry Yoo
2025-04-30 19:49 ` Mateusz Guzik
2025-05-12 11:00 ` Harry Yoo
2025-04-24 15:50 ` Christoph Lameter (Ampere) [this message]
2025-04-24 16:03 ` Mateusz Guzik
2025-04-24 16:39 ` Christoph Lameter (Ampere)
2025-04-24 17:26 ` Mateusz Guzik
2025-04-24 18:47 ` Tejun Heo
2025-04-25 10:10 ` Harry Yoo
2025-04-25 19:03 ` Tejun Heo
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