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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DACD9E81E15 for ; Fri, 6 Oct 2023 15:56:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232876AbjJFP4A (ORCPT ); Fri, 6 Oct 2023 11:56:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231495AbjJFPz6 (ORCPT ); Fri, 6 Oct 2023 11:55:58 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 500409E; Fri, 6 Oct 2023 08:55:57 -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-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=WaEf6FrRWvtJnI5YP9M3tuune/f/xvQ8jUCMeM104oA=; b=p7lYaZ7x0sCFwueHdtmZIZAewN qoKhx2eoWOrz5CzIPGPFqw19jMPfXXuCJgXuX0Ny7EYS/U5iZu7cRL6d7zTN7SheI9dz9Q12lsghM gXZj3aqzWotuB0ALp5XykK0ROpHk/mGxqaD4GRScfPqZqc+t+i4AgmkPlz6br2Hkp7buhSkR3uZxt 7KMyPyTmK0TFuBCOmq0cf9bnXeXalcS0DT+ZMBuqp12s/Uk2Q6FyGI/ZGlGs1tyvE6iIo2A5SYFeW KxxlcNJuA/BgGn5+bpJ8zcJIDFe5bF1DeeFGWmhFvhz7+JtMNcRjJDzDxMIdH9tb6mSsPz2p5JNEo U2pZt83w==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qonAL-00G9FU-Sv; Fri, 06 Oct 2023 15:55:01 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 8B3A3300392; Fri, 6 Oct 2023 17:55:01 +0200 (CEST) Date: Fri, 6 Oct 2023 17:55:01 +0200 From: Peter Zijlstra To: Mike Galbraith Cc: Marek Szyprowski , Biju Das , "bsegall@google.com" , "bristot@redhat.com" , "chris.hyser@oracle.com" , "corbet@lwn.net" , "dietmar.eggemann@arm.com" , "gregkh@linuxfoundation.org" , "joel@joelfernandes.org" , "joshdon@google.com" , "juri.lelli@redhat.com" , "kprateek.nayak@amd.com" , "linux-kernel@vger.kernel.org" , "mingo@kernel.org" , "patrick.bellasi@matbug.net" , Pavel Machek , "pjt@google.com" , "qperret@google.com" , "qyousef@layalina.io" , "rostedt@goodmis.org" , "tglx@linutronix.de" , "tim.c.chen@linux.intel.com" , "timj@gnu.org" , "vincent.guittot@linaro.org" , "youssefesmat@chromium.org" , "yu.c.chen@intel.com" , "mgorman@suse.de" , "linux-renesas-soc@vger.kernel.org" Subject: Re: [PATCH] sched/fair: fix pick_eevdf to always find the correct se Message-ID: <20231006155501.GH36277@noisy.programming.kicks-ass.net> References: <20231005150258.GA36277@noisy.programming.kicks-ass.net> <553e2ee4-ab3a-4635-a74f-0ba4cc03f3f9@samsung.com> <867f5121d7d010cacf938c293f862b0cea560ec2.camel@gmx.de> <20231006140042.GG36277@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 06, 2023 at 04:39:09PM +0200, Mike Galbraith wrote: > On Fri, 2023-10-06 at 16:00 +0200, Peter Zijlstra wrote: > > On Fri, Oct 06, 2023 at 12:31:28PM +0200, Mike Galbraith wrote: > > > On Fri, 2023-10-06 at 10:35 +0200, Marek Szyprowski wrote: > > > > > > > > > > > > Just to note, I've run into this issue on the QEmu's 'arm64/virt' > > > > platform, not on the Samsung specific hardware.  > > > > > > It doesn't appear to be arch specific, all I have to do is enable > > > autogroup, raspberry or x86_64 desktop box, the occasional failure > > > tripping over task groups, leaving both best and best_left with > > > identical but not what we're looking for ->min_deadline. > > > > OK, autogroups enabled and booted, /debug/sched/debug shows autogroups > > are indeed in existence. > > > > I've ran hackbench and a kernel build, but no whoopsie yet :-( > > > > I suppose I'll kick some benchmarks and go make a cup 'o tea or > > something. > > Hm, just booting gets me a handful, and generic desktop activity > produces a fairly regular supply. This is virgin 6.6.0.ga9e6eb3-tip. You're running that systemd thing, eh? If I create two groups (or two users with autogroup on) and have them both build a kernel I do indeed get splat. And yeah, min_deadline is hosed somehow. migration/28-185 [028] d..2. 70.264274: validate_cfs_rq: --- / migration/28-185 [028] d..2. 70.264277: __print_se: ffff88845cf48080 w: 1024 ve: -58857638 lag: 870381 vd: -55861854 vmd: -66302085 E (11372/tr) migration/28-185 [028] d..2. 70.264280: __print_se: ffff88810d165800 w: 25 ve: -80323686 lag: 22336429 vd: -41496434 vmd: -66302085 E (-1//autogroup-31) migration/28-185 [028] d..2. 70.264282: __print_se: ffff888108379000 w: 25 ve: 0 lag: -57987257 vd: 114632828 vmd: 114632828 N (-1//autogroup-33) migration/28-185 [028] d..2. 70.264283: validate_cfs_rq: min_deadline: -55861854 avg_vruntime: -62278313462 / 1074 = -57987256 I need to go make dinner (kids hungry), but I'll see if I can figure out how this happens...