linux-kernel - Re: [PATCH 0/2] KVM: arm64: Fix sleeping while atomic BUG() on OOM

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Message-Id: <159774684758.2661110.9212490740883121538.b4-ty@kernel.org>
Date:   Tue, 18 Aug 2020 11:34:20 +0100
From:   Marc Zyngier <maz@...nel.org>
To:     kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Will Deacon <will@...nel.org>
Cc:     Suzuki K Poulose <suzuki.poulose@....com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        James Morse <james.morse@....com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Paul Mackerras <paulus@...abs.org>
Subject: Re: [PATCH 0/2] KVM: arm64: Fix sleeping while atomic BUG() on OOM

On Tue, 11 Aug 2020 11:27:23 +0100, Will Deacon wrote:
> While stress-testing my arm64 stage-2 page-table rewrite [1], I ran into
> a sleeping while atomic BUG() during OOM that I can reproduce with
> mainline.
> 
> The problem is that the arm64 page-table code periodically calls
> cond_resched_lock() when unmapping the stage-2 page-tables, but in the
> case of OOM, this occurs in atomic context.
> 
> [...]

Applied to kvm-arm64/pt-rework-base, thanks!

[1/2] KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()
      commit: 462a296d8a2004063ab3c6b4df07d6f165786734
[2/2] KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set
      commit: 78dcf128f9bb3a6a3950a21cf097cdc48cf3f505

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.