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[54.240.197.234]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-421088f9d3csm22238855e9.0.2024.05.24.07.18.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 24 May 2024 07:18:12 -0700 (PDT) From: Paul Durrant X-Google-Original-From: Paul Durrant Message-ID: Date: Fri, 24 May 2024 15:18:10 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: paul@xen.org Subject: Re: [RFC PATCH v3 19/21] KVM: x86: Avoid periodic KVM clock updates in master clock mode To: David Woodhouse , kvm@vger.kernel.org Cc: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, jalliste@amazon.co.uk, sveith@amazon.de, zide.chen@intel.com, Dongli Zhang , Chenyi Qiang References: <20240522001817.619072-1-dwmw2@infradead.org> <20240522001817.619072-20-dwmw2@infradead.org> Content-Language: en-US Organization: Xen Project In-Reply-To: <20240522001817.619072-20-dwmw2@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 22/05/2024 01:17, David Woodhouse wrote: > From: David Woodhouse > > When the KVM clock is in master clock mode, updating the KVM clock is > pointless. Let the periodic work 'expire', and start it running again > from kvm_end_pvclock_update() if the master clock mode is ever turned > off again. > > Signed-off-by: David Woodhouse > --- > arch/x86/kvm/x86.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > Reviewed-by: Paul Durrant