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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 AB819C433ED for ; Wed, 12 May 2021 11:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 766B3613D6 for ; Wed, 12 May 2021 11:40:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230320AbhELLlt (ORCPT ); Wed, 12 May 2021 07:41:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:48012 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230293AbhELLlr (ORCPT ); Wed, 12 May 2021 07:41:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E8690B048; Wed, 12 May 2021 11:40:38 +0000 (UTC) Date: Wed, 12 May 2021 12:40:35 +0100 From: Mel Gorman To: Peter Zijlstra Cc: tglx@linutronix.de, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, bsingharora@gmail.com, pbonzini@redhat.com, maz@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, riel@surriel.com, hannes@cmpxchg.org, Jonathan Corbet Subject: Re: [PATCH 7/6] delayacct: Add sysctl to enable at runtime Message-ID: <20210512114035.GH3672@suse.de> References: <20210505105940.190490250@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, May 10, 2021 at 02:05:13PM +0200, Peter Zijlstra wrote: > > Just like sched_schedstats, allow runtime enabling (and disabling) of > delayacct. This is useful if one forgot to add the delayacct boot time > option. > > Signed-off-by: Peter Zijlstra (Intel) > --- > Documentation/accounting/delay-accounting.rst | 6 ++-- > kernel/delayacct.c | 36 ++++++++++++++++++++++++-- > kernel/sysctl.c | 12 ++++++++ > 3 files changed, 50 insertions(+), 4 deletions(-) > Update sysctl/kernel.rst? diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 1d56a6b73a4e..5d9193bd8d27 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1087,6 +1087,13 @@ Model available). If your platform happens to meet the requirements for EAS but you do not want to use it, change this value to 0. +sched_delayacct +=============== + +Enables/disables task delay accounting (see +:doc:`accounting/delay-accounting.rst`). Enabling this feature incurs +a small amount of overhead in the scheduler but is useful for debugging +and performance tuning. It is required by some tools such as iotop. sched_schedstats ================ -- Mel Gorman SUSE Labs