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([2001:b07:6468:f312:6c1d:63cc:b81d:e1a9]) by smtp.gmail.com with ESMTPSA id o4sm2442172wmh.35.2019.07.03.07.13.30 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Wed, 03 Jul 2019 07:13:30 -0700 (PDT) Subject: Re: [PATCH v4 1/2] KVM: LAPIC: Optimize timer latency consider world switch time To: Wanpeng Li , LKML , kvm Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Sean Christopherson References: <1560474949-20497-1-git-send-email-wanpengli@tencent.com> <1560474949-20497-2-git-send-email-wanpengli@tencent.com> From: Paolo Bonzini Message-ID: <18fd2372-45d8-0bff-79e7-373a8b7d129c@redhat.com> Date: Wed, 3 Jul 2019 16:13:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/07/19 02:48, Wanpeng Li wrote: > Hi Paolo, how about this patchset? Patch 2/2 is easy to take, do you > have more concern about patch 1/2? I don't know. It seems somewhat hard to tune and in cyclictest it only happens for preemption_timer=N. Are you using preemption_timer=N together with the LAPIC-timer-on-service-CPU patches? Paolo