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References: <20221220184813.1908318-1-roman.gushchin@linux.dev>
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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 20 Dec 2022 11:53:25 -0800
Message-ID: <CALvZod7WNxj0vdfiEad_xfBACsJu3iA0nF25m4VN3M=yLF4igg@mail.gmail.com>
Subject: Re: [PATCH RFC] ipc/mqueue: introduce msg cache
To:     Roman Gushchin <roman.gushchin@linux.dev>,
        Vlastimil Babka <vbabka@suse.cz>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Muchun Song <muchun.song@linux.dev>,
        Andrew Morton <akpm@linux-foundation.org>,
        Waiman Long <longman@redhat.com>,
        Sven Luther <Sven.Luther@windriver.com>
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+Vlastimil

On Tue, Dec 20, 2022 at 10:48 AM Roman Gushchin
<roman.gushchin@linux.dev> wrote:
>
> Sven Luther reported a regression in the posix message queues
> performance caused by switching to the per-object tracking of
> slab objects introduced by patch series ending with the
> commit 10befea91b61 ("mm: memcg/slab: use a single set of kmem_caches for all
> allocations").
>
> To mitigate the regression cache allocated mqueue messages on a small
> percpu cache instead of releasing and re-allocating them every time.
>

Seems fine with me but I am wondering what is stopping us to do this
caching in the slab layer for all accounted allocations? Does this
only make sense for specific scenarios/use-cases?