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

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Message-ID: <CAHVum0emXzjbG0B1MSNbj-iTakQ3_s6ouCL1r8Q5YVgSJQjQJA@mail.gmail.com>
Date: Tue, 5 Nov 2024 09:24:47 -0800
From: Vipin Sharma <vipinsh@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>
Cc: pbonzini@...hat.com, dmatlack@...gle.com, 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 Mon, Nov 4, 2024 at 10:01 PM Sean Christopherson <seanjc@...gle.com> wrote:
>
> 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

Thanks for doing it. Looks good to me.