Received: by 2002:a05:7412:2a8c:b0:e2:908c:2ebd with SMTP id u12csp3517382rdh; Thu, 28 Sep 2023 14:14:33 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGFd4eDG/d62tduF/WGW8CTkFygZQ4Amvzt3e8cfKvg50osRfkZ9u1gnXiqUmLA/B5W9/qe X-Received: by 2002:a05:6a00:440d:b0:68f:c4a2:fb1f with SMTP id br13-20020a056a00440d00b0068fc4a2fb1fmr3855324pfb.8.1695935672741; Thu, 28 Sep 2023 14:14:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1695935672; cv=none; d=google.com; s=arc-20160816; b=RUg6htp3fSRd29Xmob8XQllv+v/B/K8eESWHpqRfD1Bd+/54k0AeRGLt85T4QV29aG 7gDepdS6Y2ur/UVYJMekh6UQKg44Kx1R3wHpbOlj1v8EOJYOMeunBSFXbd6JBG5LTG5J zUoxKTjwgdFw7Y2IO2MNN7LUIQG/hENUEq7vjtaVJlgVna0vv9r3orMGvBaWoPJM0UCy tiLiTqzPZcWZAJgUhP6eFAlQQFoeMOpTVMTwLEd57Q0TofvAXZCqQgOuBNKTuENJAu+9 mtDn0+xb5EyUv/x6faec6WPcqTZn0PDX1fcZ3PH7kMtnDyozfLGjMsa01YMzrj2n5+DX weww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=z8GzI+kpy3OQpRgGXC2447CS8SW2V4ydnhao9KzknII=; fh=Ybekm7YJc94kBN1wJcmzDdB5NWacV4Fo3bcxigdIiXo=; b=SYElirelXh/O1Byvkkto+sP/XpRH9bXH71AznbNgBi7Q52zn2mV2xQFBuEYkeX3wMc aFXABKjZFvR+Ysfchpwxim83Lhs4U89o/guq7sKDYXXreBiGG/ZMPSB78nEKpzLhsNDp qP9oUUj62iA1fkPOja6V0LYcRQUAkYi+vM2vBjmt8AHXt1qB/KwaKEEJPUvGeOSMaVkI sxr/tnMuzlZxnFQmLtTygSN11gTa97fTV94ozVVPwnDfAyTI5RcrTsX1r1wULDWGEBwW E1p8ZOEsTmhD6OQY1wp3WoL9Y5iVnREdDpm14mH2tYoIkLd00viYQRbkU8VsPu4m1a6j VZwA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=dv67282F; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from howler.vger.email (howler.vger.email. [2620:137:e000::3:4]) by mx.google.com with ESMTPS id cl6-20020a056a0032c600b0069339f19f7dsi5272778pfb.199.2023.09.28.14.14.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Sep 2023 14:14:32 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=dv67282F; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by howler.vger.email (Postfix) with ESMTP id 0263C8348238; Thu, 28 Sep 2023 01:38:17 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at howler.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231301AbjI1IiF (ORCPT + 99 others); Thu, 28 Sep 2023 04:38:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229639AbjI1IiD (ORCPT ); Thu, 28 Sep 2023 04:38:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34EA4AC; Thu, 28 Sep 2023 01:38:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=z8GzI+kpy3OQpRgGXC2447CS8SW2V4ydnhao9KzknII=; b=dv67282FkROq+rxj7+zjDGZRAe c22MFYLUqQdFaCICkn9c/JwsLXsziF0Aa20hcfdtVvZS5oBuvH3QP3jMmHtxf2fjgEJV73X36DTdQ 6IzQ4OCBy66CT3a7cysZmfV+HA2C4in6oIQdQR3rCpNoSzy8YxY0zibLNv44OyQxHHDSIs+SyEErx TGvjE3zNZeg/3STOiQjol+U9rc9rJICOb7O+Q1RXUJMC+/aWSVPrH5LgRbMGDp50KuY7L3uG4S79Q 2+Mlf7Y6gZPWtolavgWqnvLATMQN603fWGfdIjB624EavJCtWYuIKsCIGdF9F3N2W5SrBBELiW6Cj G8vY/z9A==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qlmWh-001RzB-JE; Thu, 28 Sep 2023 08:37:39 +0000 Date: Thu, 28 Sep 2023 09:37:39 +0100 From: Matthew Wilcox To: Peter Zijlstra Cc: Xiaobing Li , mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, axboe@kernel.dk, asml.silence@gmail.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, kun.dou@samsung.com, peiwei.li@samsung.com, joshi.k@samsung.com, kundan.kumar@samsung.com, wenwen.chen@samsung.com, ruyi.zhang@samsung.com Subject: Re: [PATCH 3/3] IO_URING: Statistics of the true utilization of sq threads. Message-ID: References: <20230928022228.15770-1-xiaobing.li@samsung.com> <20230928022228.15770-4-xiaobing.li@samsung.com> <20230928080114.GC9829@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230928080114.GC9829@noisy.programming.kicks-ass.net> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Thu, 28 Sep 2023 01:38:17 -0700 (PDT) On Thu, Sep 28, 2023 at 10:01:14AM +0200, Peter Zijlstra wrote: > Now, I see what you're trying to do, but who actually uses this data? I ... don't. There seems to be the notion that since we're polling, that shouldn't count against the runtime of the thread. But the thread has chosen to poll! It is doing something! For one thing, it's preventing the CPU from entering an idle state. It seems absolutely fair to accuont this poll time to the runtime of the thread. Clearly i'm missing something.