From: Sean Christopherson <seanjc@google.com>
To: Liang Chen <liangchen.linux@gmail.com>
Cc: pbonzini@redhat.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Vipin Sharma <vipinsh@google.com>,
David Matlack <dmatlack@google.com>
Subject: Re: [PATCH] KVM: x86/mmu: Register MMU shrinker only when necessary
Date: Wed, 14 Aug 2024 07:41:19 -0700 [thread overview]
Message-ID: <ZrzCD-cL4N1DsRaO@google.com> (raw)
In-Reply-To: <20240814082302.50032-1-liangchen.linux@gmail.com>
+Vipin and David
On Wed, Aug 14, 2024, Liang Chen wrote:
> The shrinker is allocated with TDP MMU, which is meaningless except for
> nested VMs, and 'count_objects' is also called each time the reclaim
> path tries to shrink slab caches. Let's allocate the shrinker only when
> necessary.
This is definitely not worth the complexity. In its current form, KVM's shrinker
is quite useless[1], and there were plans to repurpose the shrinker to free pages
from the so called "mmu caches"[2], i.e. free pages that are guaranteed to not be
in use.
Vipin/David, what happened to that series? Are we still working on it?
[1] https://lore.kernel.org/lkml/Y45dldZnI6OIf+a5@google.com
[2] https://lore.kernel.org/all/20221222023457.1764-2-vipinsh@google.com
next prev parent reply other threads:[~2024-08-14 14:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-14 8:23 [PATCH] KVM: x86/mmu: Register MMU shrinker only when necessary Liang Chen
2024-08-14 14:41 ` Sean Christopherson [this message]
2024-08-19 21:40 ` Vipin Sharma
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