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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 0479CECDFBB for ; Fri, 20 Jul 2018 10:17:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B107A20673 for ; Fri, 20 Jul 2018 10:17:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pEFOwmDU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B107A20673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728223AbeGTLFK (ORCPT ); Fri, 20 Jul 2018 07:05:10 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:41568 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727179AbeGTLFJ (ORCPT ); Fri, 20 Jul 2018 07:05:09 -0400 Received: by mail-oi0-f68.google.com with SMTP id k12-v6so20409437oiw.8; Fri, 20 Jul 2018 03:17:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=eoQOWcYjPyrQL46BBZRMuAPHgOx+/WdSaZT5yDOAx/0=; b=pEFOwmDUYpDGU+KuSdsiHhUeoo2LKO4fL4/keerfuvoPMZitLNfu+EZjnU8ZIVehFk XTwpaTn0swLy8EuHc+8NvKWn5s96W/E7FQrBpOSk5o1QLQOae6IAtKqa5vKnOq3jzJJi H8EhgSjA0R5O8bHR1JOKO1VPpLFN58gbdA9Tup/IyX6ynd92mHRCpwGkG06bpGnNUbEg 59jmUILy3CrfGYM3iks30nBL0WGr21C2oh6YTWcO1JXCwc8QJPi+s7/qhoptEoxjjjJA 6GXyepVlWk/p6G50f585KgcjY7xap3Jz8N1tjUp4M8W5ThmxQ5/7lbY5nKjTQm3bjMoS EGpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=eoQOWcYjPyrQL46BBZRMuAPHgOx+/WdSaZT5yDOAx/0=; b=e+/AF02HG3KgJS8cUy3cpFJpBs7N5szhtWrNrJgbUI3ia56VArijq2YDOhuQjYFhCH bkomNrVJoakId4jBtgNK87kp26vG3p0+7ymFHviiXHqg1vctg08GJ/8s0KrTZaQ7mzn4 hfx2ICk1gX7edcKy0n8x/j6NKuwdWzVUzUb42qjU2Zn3DfcB8fmKI+RJo74itoiWm0d1 LaVEfVS0Pkru+aIJuzqun9rMSLjP3+7rRvH7NmHl7HjLhpRXc2JIP7DuUesSeBfp1uPF /3HIbWviRnwLERnMz+JE/ssDth88pY+ngBMKAw7o7wDeVy/9AK+7wtjo/M8g7XrWQftD X5vg== X-Gm-Message-State: AOUpUlFoZ9WuRdKh/uJ2oTffdgDq6Oj2llxnEwtGjAPcrzbzdtB2Pzl+ 8+kEw+OqoPB701vFdiWaGUUBxw1DIlywOeJiOi4= X-Google-Smtp-Source: AAOMgpfNLjB6WOzcSYwqXEecnreCyky5unVAr6OjYnXejSlKUVO8R0zVjYEKs71u+2alVoUvTQyefKfh4bI666Nve2I= X-Received: by 2002:aca:ad4f:: with SMTP id w76-v6mr1487902oie.233.1532081856269; Fri, 20 Jul 2018 03:17:36 -0700 (PDT) MIME-Version: 1.0 References: <1530598891-21370-1-git-send-email-wanpengli@tencent.com> <1530598891-21370-3-git-send-email-wanpengli@tencent.com> <20180719162826.GB11749@flask> <20180720095135.GA8330@flask> In-Reply-To: <20180720095135.GA8330@flask> From: Wanpeng Li Date: Fri, 20 Jul 2018 18:17:40 +0800 Message-ID: Subject: Re: [PATCH v3 2/6] KVM: X86: Implement PV IPIs in linux guest To: Radim Krcmar Cc: LKML , kvm , Paolo Bonzini , Vitaly Kuznetsov Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Jul 2018 at 17:51, Radim Krcmar wrote: > > 2018-07-20 11:33+0800, Wanpeng Li: > > On Fri, 20 Jul 2018 at 00:28, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > > > 2018-07-03 14:21+0800, Wanpeng Li: > > > But because it is very similar to x2apic, I'd really need some real > > > performance data to see if this benefits a real workload. > > > > Thanks for your review, Radim! :) I will find another real benchmark > > instead of the micro one to evaluate the performance. > > Analyzing the cpu bitmap for every IPI request on a non-small guest (at > least 32 VCPUs, ideally >256) during various workloads could also > provide some insight regardless of workload/benchmark result -- we want > to know how many VM exits we would save. I will try ebizzy benchmark, just complete the patchset w/ __uint128 which Paolo just suggested. In addition, I remember aliyun posted the performance number for their online real workload "message oriented middleware" from 800 k/s vmexits w/ PV IPIs to 150 k/s vmexits w/ PV IPIs. Regards, Wanpeng Li