linux-kernel - Re: [PATCH v3 0/1] Remove KVM MMU shrinker

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Message-ID: <173078270653.2038440.10448863177930046934.b4-ty@google.com>
Date: Mon,  4 Nov 2024 21:56:11 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, pbonzini@...hat.com, dmatlack@...gle.com, 
	Vipin Sharma <vipinsh@...gle.com>
Cc: zhi.wang.linux@...il.com, weijiang.yang@...el.com, mizhang@...gle.com, 
	liangchen.linux@...il.com, kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 0/1] Remove KVM MMU shrinker

On Fri, 01 Nov 2024 13:14:36 -0700, Vipin Sharma wrote:
> Based on the feedback from v2, this patch is now completely removing KVM MMU
> shrinker whereas earlier versions were repurposing KVM MMU shrinker
> behavior to shrink vCPU caches. Now, there is no change to vCPU caches
> behavior.
> 
> KVM MMU shrinker is not very effective in alleviating pain during memory
> pressure. It frees up the pages actively being used which results in VM
> degradation. VM will take fault and bring them again in page tables.
> More discussions happened at [1]. Overall, consensus was to reprupose it
> into the code which frees pages from KVM MMU page caches.
> 
> [...]

Applied to kvm-x86 mmu, with the massaging and splitting.  Definitely feel free
to propose changes/object.  I wanted to get this queued asap to get coverage in
-next, but I don't anticipate any more MMU commits, i.e. I can fix these up
without too much fuss.  Thanks!

[1/2] KVM: x86/mmu: Remove KVM's MMU shrinker
      https://github.com/kvm-x86/linux/commit/fe140e611d34
[2/2] KVM: x86/mmu: Drop per-VM zapped_obsolete_pages list
      https://github.com/kvm-x86/linux/commit/4cf20d42543c

--
https://github.com/kvm-x86/linux/tree/next