From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] KVM: x86/mmu: Always guard rmaps with mmu_lock on PREEMPT_RT=y kernels
Date: Mon, 21 Sep 2026 07:05:22 -0700 [thread overview]
Message-ID: <178999884535.741435.243109419293478594.b4-ty@google.com> (raw)
In-Reply-To: <20260902211759.2700289-1-seanjc@google.com>
On Wed, 02 Sep 2026 14:17:59 -0700, Sean Christopherson wrote:
> For all intents and purposes, revert KVM's ability to walk rmaps outside of
> mmu_lock when running on a realtime (PREEMPT_RT=y) kernel. I.e. don't use
> a non-sleepable bit-spinlock to protect rmap entries, as realtime kernels
> are highly unlikely to benefit from increased aging throughput and reduced
> jitter for memory-overcommitted nested VMs, whereas using a non-sleepable
> lock is currently buggy and goes against the spirit of realtime kernels.
>
> [...]
Applied to kvm-x86 mmu, thanks!
[1/1] KVM: x86/mmu: Always guard rmaps with mmu_lock on PREEMPT_RT=y kernels
https://github.com/kvm-x86/linux/commit/df269c8e097f
--
https://github.com/kvm-x86/linux/tree/next
prev parent reply other threads:[~2026-09-21 14:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-02 21:17 Sean Christopherson
2026-09-02 21:42 ` James Houghton
2026-09-02 22:27 ` Sean Christopherson
2026-09-02 22:38 ` David Woodhouse
2026-09-21 14:05 ` Sean Christopherson [this message]
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