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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL 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 D4D4DC433ED for ; Fri, 30 Apr 2021 15:49:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC93961462 for ; Fri, 30 Apr 2021 15:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231326AbhD3PuJ (ORCPT ); Fri, 30 Apr 2021 11:50:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230152AbhD3PuI (ORCPT ); Fri, 30 Apr 2021 11:50:08 -0400 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CD2CC06174A for ; Fri, 30 Apr 2021 08:49:20 -0700 (PDT) Received: by mail-lf1-x130.google.com with SMTP id h36so56634603lfv.7 for ; Fri, 30 Apr 2021 08:49:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=N/UPUp4HGQ7DUeHHfUkqK9fCJ9kbgVk9zzLyqLqjGfM=; b=RNDNI9bO32iPq815h6PEKYMHm9ubqdtxdPpz0MYKrikxt/WRGVn2PCO53QFc4kl1l+ +H/Me1WPAUS78AzlQKSe1l+mtUy2B/u2d7M8MhhlXdCch2TieSeIhp6FZIVtDX4UB2Tb G8wLchTSng1b1MM6SHwqCE58wBt12SAw4e+xMeOmjXpiGZlCVk7asNXwkpgH76O+6AoI zsCFbePd3iJmd2+wpwfwRvTabsOyjEUqHYvuOJz+g/0MCozNX8k+rIF7xexPC59WMQm/ 9VJPziljufYbwH1BhAUEhsriAUzDjMGZS2DfF3Nwjwm/jgoWWBnns37NFDaVz5FFtHNH 3SvA== 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; bh=N/UPUp4HGQ7DUeHHfUkqK9fCJ9kbgVk9zzLyqLqjGfM=; b=SchKLL2C6vxHNxkOpMQZzUryp9jqw8uIyjDy9O8018d+GiMjkCZ2udqPHgjX8OXQLr Q/rirOJ6H3KYk1Niy2iiydb7e2+v97ragDjjBY2P0SBWR6FXn1O55e0MB7Y2OXtNTBsm mIx2dil3bxxcsnukMa/CyaIFPTOC7DUeYkrnQDFeWax0pMbh840e9+Tpw31xzGZPDeLS egpNiMXuZzAWdU3DGg59kNlGjr9CGIQeOxrzyIkdv0nBTYlw++CnvGPEZ7TZVRnLdyyd JItkz5jy0rdmZK66HKW+h0YUvuR9QG+WkozHIFGBBK2uFBGxWYl45oLpd+Ze88K4rXzb QRfg== X-Gm-Message-State: AOAM531OHuMovcEA9dDSmZlrzt9Z6sR6EBX5zQarRJdzuT5/fVgi/Epd jdUuZ1CgmzFyxRB1DPt3p1ESjU378qgOa7iy/qqkeA== X-Google-Smtp-Source: ABdhPJyP6PCLmh4e9bLc4x603SQsBDJnGdbm4xuuVPZwgz3jH/5LEJSNs2axdGI+b3kYh732duvxzboW/5Z8cXMSEhY= X-Received: by 2002:a19:c511:: with SMTP id w17mr3793880lfe.80.1619797758532; Fri, 30 Apr 2021 08:49:18 -0700 (PDT) MIME-Version: 1.0 References: <20210429162233.116849-1-venkateshs@chromium.org> In-Reply-To: <20210429162233.116849-1-venkateshs@chromium.org> From: David Matlack Date: Fri, 30 Apr 2021 08:48:51 -0700 Message-ID: Subject: Re: [PATCH] kvm: exit halt polling on need_resched() as well To: Venkatesh Srinivas Cc: kvm list , Jim Mattson , Paolo Bonzini , Benjamin Segall Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Apr 29, 2021 at 9:22 AM Venkatesh Srinivas wrote: > > From: Benjamin Segall > > single_task_running() is usually more general than need_resched() > but CFS_BANDWIDTH throttling will use resched_task() when there > is just one task to get the task to block. This was causing > long-need_resched warnings and was likely allowing VMs to > overrun their quota when halt polling. > > Signed-off-by: Ben Segall > Signed-off-by: Venkatesh Srinivas Reviewed-by: David Matlack