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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 A6413C4649B for ; Fri, 5 Jul 2019 09:50:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84D2621850 for ; Fri, 5 Jul 2019 09:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728368AbfGEJut (ORCPT ); Fri, 5 Jul 2019 05:50:49 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:43772 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728358AbfGEJut (ORCPT ); Fri, 5 Jul 2019 05:50:49 -0400 Received: by mail-wr1-f67.google.com with SMTP id p13so9235515wru.10 for ; Fri, 05 Jul 2019 02:50:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YUgV9oyAP3Ji8jA9MSEhvMmGZhPCnmuMeRDLIoIYTW0=; b=hA81FD+HlYB6kqeHOeqpFItjrKxIL+OtIMgtISvfoeyLVY4OFPoFSXHj1YpRgNdmaX IxRZ4O9LdW6AZP18T87E0Creq6J/aWsagnTXWYM4MdjuhWHxlVE7zTU1lI+cPXKFV4wU ZVt6+0wDJNG+RloHH3f31gYwq1nUFmejyvNo7nzI2s+CziA0n6kV55xHnB94ZpbEjIin 5b1U5DDZxY5mpyYKExRxXY+Gn9JgZqvd1wZeNVLeRKRe7RNyLfqqmZudbajFiZRYTLKX gZ28ClBeWIBOLb/4RabwxKg4Kw1wc8nQe0H9xy5N5nlBZMhLDguKFcGJ02d/R/RkkwX9 iQDg== X-Gm-Message-State: APjAAAWAMWfg4+A5OVKjxHkdkqZgYoypXz9ogQHPUjYE+e/5LW8tFPoH vTeKk1CQu1WK00IsxmyGO0bLLg== X-Google-Smtp-Source: APXvYqypJu/BEjih6IidHXtaQ3xrNB0U+85zf/Y9MMWD6a3bCmLx/E4SeqEvaBrNU348XT146MdsGQ== X-Received: by 2002:a5d:5492:: with SMTP id h18mr3261472wrv.212.1562320246561; Fri, 05 Jul 2019 02:50:46 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:19db:ad53:90ea:9423? ([2001:b07:6468:f312:19db:ad53:90ea:9423]) by smtp.gmail.com with ESMTPSA id z1sm8749189wrv.90.2019.07.05.02.50.45 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Fri, 05 Jul 2019 02:50:46 -0700 (PDT) Subject: Re: [PATCH] KVM: LAPIC: Reset timer_advance_ns to 1000 after adaptive tuning goes insane To: Wanpeng Li , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <1562319651-6992-1-git-send-email-wanpengli@tencent.com> From: Paolo Bonzini Message-ID: Date: Fri, 5 Jul 2019 11:50:45 +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: <1562319651-6992-1-git-send-email-wanpengli@tencent.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/07/19 11:40, Wanpeng Li wrote: > From: Wanpeng Li > > Reset timer_advance_ns to the default value 1000ns after adaptive tuning > goes insane which can happen sporadically in product environment. > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Signed-off-by: Wanpeng Li > --- > arch/x86/kvm/lapic.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index 05d8934..454d3dd 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1549,7 +1549,7 @@ static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu, > if (abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_DONE) > apic->lapic_timer.timer_advance_adjust_done = true; > if (unlikely(timer_advance_ns > 5000)) { > - timer_advance_ns = 0; > + timer_advance_ns = 1000; > apic->lapic_timer.timer_advance_adjust_done = true; Do you also want to reset timer_advance_adjust_done to false? Paolo > } > apic->lapic_timer.timer_advance_ns = timer_advance_ns; >