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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 22103C433ED for ; Mon, 10 May 2021 07:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9C5C61432 for ; Mon, 10 May 2021 07:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230098AbhEJHKH (ORCPT ); Mon, 10 May 2021 03:10:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230002AbhEJHKG (ORCPT ); Mon, 10 May 2021 03:10:06 -0400 Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C68CC061573; Mon, 10 May 2021 00:09:01 -0700 (PDT) Received: by mail-ej1-x635.google.com with SMTP id l4so22872403ejc.10; Mon, 10 May 2021 00:09:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=0CHUOqR7/6H1oK4FSD7YVVjmtCKdO0zZLijsAd48zvc=; b=mf3VK1MIRy4CFEQRAmNjb53ZfY4H1BMaZ0Gx3dZEcf8ctXJoZWDf2jEMhvIxzoxyuI BUOKek91RdMkyVUBdaw+t6bLWgL2d73H25g2MzE6bz7oLD8ivDuzly/qmkrxXbmDNH7R Rq/zMQTU0/TraVY3jD+H/gRwC4BQQiBWmkaCdjajNLqc+u4+4cxWfAATSzn/cddM2y2a DwAEESVIoRedDEmNA7wGfggknVVvIPc8cnrDWxjH5ElfNIbuqQCSTxBXHnq8HooH6UVT jqV9st5IZ7T4AO5HpBerfcFGe/jcVvkh9tteM8LqIwDoHqgrCauHlEO13tRyR6shsEN5 dK8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=0CHUOqR7/6H1oK4FSD7YVVjmtCKdO0zZLijsAd48zvc=; b=mCY03Vjt16wtTeI2b3O29dHmGRgFXbfl/vIxTWrPBtsx53Y6Duf6QG7XlTwYz9gjh7 LU5nWMFqeV3O/Sntb9b0PiAoIrNz2HDBh6YzLwNQ68Hn8uLzbfHZw5/1bvmEuat6++F5 bhfD9RMxBt/lzD6r0dInwAPGRPbpuFa9N7JBH5u0qvhgLO755eh8Tt2JztTE51brvr2K zbzbo1145JImgAneq6OSqNp7AYX1PLgwtaZ61IoLgrRpvb+sC1i1WP+JkUwC1tEqmVGi P3zjdYsm8ZgqmzbtS1TQuXE4JCfogVqHBrjXAmMXmV/PqBW8/fb1p4tFXQoysyHg6H1e rAUw== X-Gm-Message-State: AOAM533XQ+8x/yK+KuBZFOH9QjZCDSWEywDu9kYa9K2mhVlpRKwJe1Uy tXeboaI0X9q57VlArBKUZ5ok9Ac5LsE= X-Google-Smtp-Source: ABdhPJy+LzEA5+0rdJ8WUcSRzq+XV6TJr5bczBiF93K/R+YPbIxKej5mYDyRmXkWloihWvNfWtNVJA== X-Received: by 2002:a17:907:3e23:: with SMTP id hp35mr24575568ejc.437.1620630540127; Mon, 10 May 2021 00:09:00 -0700 (PDT) Received: from gmail.com (0526E777.unconfigured.pool.telekom.hu. [5.38.231.119]) by smtp.gmail.com with ESMTPSA id p4sm8413406ejr.81.2021.05.10.00.08.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 May 2021 00:08:59 -0700 (PDT) Sender: Ingo Molnar Date: Mon, 10 May 2021 09:08:57 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: tglx@linutronix.de, 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, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, riel@surriel.com, hannes@cmpxchg.org Subject: Re: [PATCH 0/6] sched,delayacct: Some cleanups Message-ID: References: <20210505105940.190490250@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210505105940.190490250@infradead.org> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org * Peter Zijlstra wrote: > Hi, > > 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: Ingo Molnar (This includes the #6 RFC patch.) Thanks, Ingo