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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 F354CC63793 for ; Thu, 22 Jul 2021 05:55:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD4B061244 for ; Thu, 22 Jul 2021 05:55:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230136AbhGVFOm (ORCPT ); Thu, 22 Jul 2021 01:14:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229575AbhGVFOm (ORCPT ); Thu, 22 Jul 2021 01:14:42 -0400 Received: from mail-ot1-x335.google.com (mail-ot1-x335.google.com [IPv6:2607:f8b0:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE25EC061575; Wed, 21 Jul 2021 22:55:17 -0700 (PDT) Received: by mail-ot1-x335.google.com with SMTP id t4-20020a05683014c4b02904cd671b911bso4317932otq.1; Wed, 21 Jul 2021 22:55:17 -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=QN1ev8xMwchF2OgXjdPYWOEMPX7NTDgCOlrkD31eHy4=; b=jXrxmZJNZKZMR9nJLKg12DQL0nmaYL9hhCUQqsvCCpU3MDlWGd6W3L0KAv4A1l0Bxs O49BNZHWTOm59l8a1tb0ls/CCE2d6pGrXOCfLbkdd7FMdE9YZg366mgZ/xdosogjpOdh s6suBfuI7N6pXy2e3DnP+h10C2HojMr0uuxPscbgly6TeJv4Amd9muuFFOWmxzvQXq6W pvoE+f8nrj7TtK60TULkckULR2Z09kB0CBZiGDp9c8A//O29LmykMZQUijA3EPanl4WA fSrDiCEQk9aToeKCtpeAaJqdcmMaJWlJzXdkrOhRdTxmn/o/jeBl/KPLWDqyL18IwQbV h59w== 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=QN1ev8xMwchF2OgXjdPYWOEMPX7NTDgCOlrkD31eHy4=; b=L+U5QZl7F9hz+YpezWZ8APr7qqN3APdRhszzvH7sHMZjrkyet4ZXKjfmeEJPq6veAk QORNnMBM0c/lJmtsehZ1ulk7AKZupN2uMjM/sjHOGU3vg+gccoI5gpwRHRqqp+MssC5M OJ+KOWC1tg4VGsuRm4vnjDSFpfeb+OMwsR1hEScQQWlTi8gyrCgZXnnbTA4VTGnkhJn+ rvNaXpA00DyRSkWf2ckfWWrxH510HhPjKrwvM00umKXGT1mbrnZcBkXjXEtJM+b28VM0 4aovmR70FfDP163qsjmYG9seA/IGg0QSEvW5UUCQ46yojMrkxgN6opzwSGG4g7z7zDCX f56w== X-Gm-Message-State: AOAM532oUAFNGUsdJgo8QVVNJVzW7sXY0S7z172V8T1+HT0v+WHftEMZ QuYGK/kk0QoW9UJj1zN34kxSPPlyKvnaY8b3NSk= X-Google-Smtp-Source: ABdhPJzWBO3wCgmM9LAYq4MVGYjry+20++zWVDC3YkTy5ZPLMEFRey4r54ODWnh6J3rVhDdP+71E4dhyPBVca9VFHjY= X-Received: by 2002:a9d:4f02:: with SMTP id d2mr21148711otl.254.1626933317333; Wed, 21 Jul 2021 22:55:17 -0700 (PDT) MIME-Version: 1.0 References: <20210722035807.36937-1-lirongqing@baidu.com> In-Reply-To: <20210722035807.36937-1-lirongqing@baidu.com> From: Wanpeng Li Date: Thu, 22 Jul 2021 13:55:06 +0800 Message-ID: Subject: Re: [PATCH] KVM: Consider SMT idle status when halt polling To: Li RongQing Cc: Paolo Bonzini , Ingo Molnar , Peter Zijlstra , kvm , LKML Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 22 Jul 2021 at 12:07, Li RongQing wrote: > > SMT siblings share caches and other hardware, halt polling > will degrade its sibling performance if its sibling is busy Do you have any real scenario benefits? As the polling nature, some cloud providers will configure to their preferred balance of cpu usage and performance, and other cloud providers for their NFV scenarios which are more sensitive to latency are vCPU and pCPU 1:1 pin=EF=BC=8Cyou destroy these setups. Wanpeng