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Date:   Tue, 22 Mar 2022 20:41:56 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Roman Gushchin <roman.gushchin@linux.dev>
Cc:     Stephen Brennan <stephen.s.brennan@oracle.com>,
        lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org,
        Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>,
        khlebnikov@yandex-team.ru
Subject: Re: [LSF/MM TOPIC] Better handling of negative dentries
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On Tue, Mar 15, 2022 at 01:56:18PM -0700, Roman Gushchin wrote:
> I’d be happy to join this discussion. And in my opinion it’s going
> beyond negative dentries: there are other types of objects which tend
> to grow beyond any reasonable limits if there is no memory pressure.
>
> A perfect example when it happens is when a machine is almost idle
> for some period of time. Periodically running processes creating
> various kernel objects (mostly vfs cache) which over time are filling
> significant portions of the total memory. And when the need for memory
> arises, we realize that the memory is heavily fragmented and it’s
> costly to reclaim it back.

When you say "vfs cache", do you mean page cache, inode cache, or
something else?