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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 180F8C433B4 for ; Fri, 7 May 2021 09:05:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2A3861443 for ; Fri, 7 May 2021 09:05:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234529AbhEGJGe (ORCPT ); Fri, 7 May 2021 05:06:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231422AbhEGJGe (ORCPT ); Fri, 7 May 2021 05:06:34 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 310E1C061574; Fri, 7 May 2021 02:05:35 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1620378331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=wiNZhgNtdVWskIOQqlZ//nz/pviSlraqX/NCbWN5P4k=; b=ohu10kUFW/33dp6ljK9m/sWPSCL43uSkjBXuiJ8D45AGp8AXmxuw+DfLdr0X25Td5vfSiO M0WQF1qIoSFgMy7+rqPtZtK/FbdHmqNJSD+ufzBb5gUQoRKmRmBJQQrgrq1tkN+KKBDiAj 6Y0ATUEQLmN76F0/twd9FyHT5zbtZorUuh1mdFyw77G2KHK9T1ePZwaTHotVgD2dxX4TZp iuKxZoqK0p3gDrqWpj6Vz2w0o3xNJK0F9w16qUD/o/3eyv3xuMxTtvvsX4FI4+wDHfHtdz CxeHy4cq4xUHpna/qP5jfnaLpkdJUALmvJs1p2XjTeyW8Z97qBUo4K37Q7xowQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1620378331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=wiNZhgNtdVWskIOQqlZ//nz/pviSlraqX/NCbWN5P4k=; b=/gqNc3dMAo7xS0wurbqxAzs5L8hTyLRoBpv3NoRh0Tw75X9HRAxXbPemGh9K7lmVuSzoM0 W1k7hED1pNwzf0Bw== To: Peter Zijlstra , mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, bsingharora@gmail.com, pbonzini@redhat.com, maz@kernel.org Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, peterz@infradead.org, riel@surriel.com, hannes@cmpxchg.org Subject: Re: [PATCH 0/6] sched,delayacct: Some cleanups In-Reply-To: <20210505105940.190490250@infradead.org> References: <20210505105940.190490250@infradead.org> Date: Fri, 07 May 2021 11:05:31 +0200 Message-ID: <87zgx6ncbo.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, May 05 2021 at 12:59, Peter Zijlstra wrote: > Due to: > > https://lkml.kernel.org/r/0000000000001d43ac05c0f5c6a0@google.com > > and general principle, delayacct really shouldn't be using ktime (pvclock also > really shouldn't be doing what it does, but that's another story). This lead me > to looking at the SCHED_INFO, SCHEDSTATS, DELAYACCT (and PSI) accounting hell. > > The rest of the patches are an attempt at simplifying all that a little. All > that crud is enabled by default for distros which is leading to a death by a > thousand cuts. > > The last patch is an attempt at default disabling DELAYACCT, because I don't > think anybody actually uses that much, but what do I know, there were no ill > effects on my testbox. Perhaps we should mirror > /proc/sys/kernel/sched_schedstats and provide a delayacct sysctl for runtime > frobbing. Reviewed-by: Thomas Gleixner