From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE56AC3402F for ; Tue, 18 Feb 2020 01:19:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95CD6208C4 for ; Tue, 18 Feb 2020 01:19:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ayxtwJaJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726293AbgBRBTc (ORCPT ); Mon, 17 Feb 2020 20:19:32 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:44771 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726097AbgBRBTc (ORCPT ); Mon, 17 Feb 2020 20:19:32 -0500 Received: by mail-pg1-f195.google.com with SMTP id g3so9970574pgs.11; Mon, 17 Feb 2020 17:19:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=wdl63vLkZeTCO6cEhD7wb/Lt5+ras5GaQCOoaNINnOw=; b=ayxtwJaJbgP+QbO48qMs3x/NxRg1vDVDmL+gjWbxxaU3tI1Qh0trNJeYSdUeIkwXV4 o4kD+UFWcT1uRG+LyO5jEAYfnr7gicrHdPZKy5hAORerM3yZ3dDeEGG4tkPmKL9YNKCk SjzmUR+5goMb7yJGKwPp3qarq9+Po7GmxbG000fR3pdqpp77U3BiGO422VbQB2zaCRPE vK7YImQV8c47x9QWXmB6GiS8+mQbMwv0qn+9RBfh3i0LZhGUedl/CgzinjFL6jeimtwj OhqHvDPE/+ofCJO6OceQIJeYQj8MgTOgY9vwIJy00Yg7FmzRnIBB6dGAmW9+4IsH3Ml7 4SLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=wdl63vLkZeTCO6cEhD7wb/Lt5+ras5GaQCOoaNINnOw=; b=OoGDXkMYUuF7S+0h8u5MYYB7Ce2vN4hUK1cDkbrpK1eQklWkQ6FQGZLB2dqq1GU6ep 0WpxU7L1gLLQbty50Bnvq5hojJ9KT5p+i1vxlrRyAZq818vVOcu++bquy6AoCpWF90Sl s0wJd1FdLdyJfRiR16qLLDWurmT4QFwOrlBbZy0DjI8Dw/nACpd9VCmMM24TuoZKj/Eh G+FIuyZPiA7M5lQWAu4MzLiuITURs5U19MveksBL4yS0IWn0zr5jYb91wkq8CV4l+JVG H+tYpXcILhibxErLGG0U0hq0rJAzKGQzfqvUql7/gFPa7G/QAOpqmDyPM/YHrSgVwmiS H4HQ== X-Gm-Message-State: APjAAAVoYC+nTW6hOB0kwM/SB5P/T9Z4QWzh29HrygmB3YbexBdDiS6G 95SaI+7JaYtRaXUxHtuOk6Ldhx9YlnUEZQ== X-Google-Smtp-Source: APXvYqx5VtdeS9U5CVkgXTZIeohJKxNEj2BmCVl/+Xi8BV5uynYvo/WGPRsqNJSsSroxYkw0Q5MYrQ== X-Received: by 2002:a63:38b:: with SMTP id 133mr20234538pgd.153.1581988771240; Mon, 17 Feb 2020 17:19:31 -0800 (PST) Received: from kernel.DHCP ([120.244.140.205]) by smtp.googlemail.com with ESMTPSA id g13sm1519511pfo.169.2020.02.17.17.19.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 17 Feb 2020 17:19:30 -0800 (PST) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: [PATCH v4 1/2] KVM: X86: Less kvmclock sync induced vmexits after VM boots Date: Tue, 18 Feb 2020 09:17:09 +0800 Message-Id: <1581988630-19182-1-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Wanpeng Li In the progress of vCPUs creation, it queues a kvmclock sync worker to the global workqueue before each vCPU creation completes. Each worker will be scheduled after 300 * HZ delay and request a kvmclock update for all vCPUs and kick them out. This is especially worse when scaling to large VMs due to a lot of vmexits. Just one worker as a leader to trigger the kvmclock sync request for all vCPUs is enough. Signed-off-by: Wanpeng Li --- v3 -> v4: * check vcpu->vcpu_idx arch/x86/kvm/x86.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fb5d64e..d0ba2d4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9390,8 +9390,9 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) if (!kvmclock_periodic_sync) return; - schedule_delayed_work(&kvm->arch.kvmclock_sync_work, - KVMCLOCK_SYNC_PERIOD); + if (vcpu->vcpu_idx == 0) + schedule_delayed_work(&kvm->arch.kvmclock_sync_work, + KVMCLOCK_SYNC_PERIOD); } void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) -- 2.7.4