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 3F182C00140 for ; Sun, 21 Aug 2022 11:29:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230170AbiHUL3G (ORCPT ); Sun, 21 Aug 2022 07:29:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229651AbiHUL3D (ORCPT ); Sun, 21 Aug 2022 07:29:03 -0400 Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97047140EA; Sun, 21 Aug 2022 04:29:02 -0700 (PDT) Received: by mail-ej1-x62e.google.com with SMTP id y13so16350196ejp.13; Sun, 21 Aug 2022 04:29:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc; bh=fMM08NkXjQf8LQsd9if/tOzac0dPGc2gucFpi22QVMQ=; b=Pl0IJgXimvbpN8Ay+cPjZUz7W9u9zY5Mds0dOZTqJDTZXNbMF/qhwJjS/rnUGbN1Jr KkHT++eKkZ8wDN5+on6ILJlvMOc8u5Im4o5eQJVoqCmHieLs6pkfaSd5eGfrs6eL40uK kvk2njQtHJ+p2d+cqEjOtY3JE3khnkdv36FkH6AqPqfNaCi4LHC69GZazbeizO1Pca9J r/8I2O72WqThxbqRF1WAYhthGhQ11UfD5h/yTgBQo8ENuXyyJAhQKGFHPS9tv0Ty8m3u VWFL3d+EJ3867f/GBFko/whzW2FcH4luLpibwYyUgGR/DdvHdSbg5aeQ4V1w9AZuebF2 vepw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc; bh=fMM08NkXjQf8LQsd9if/tOzac0dPGc2gucFpi22QVMQ=; b=VXvlqYG5kA3R6oP+pSghgC/LZuvisOkTkU7AV8UQCjdKwWXui6p6iwC7nUI4bimq0X sGrmZCetKryTRNjcfIjN0o0KA73vapJYBEaGBw02W8rmsiClec+9NgRRaB88MhZmFbms /gAjpa6U87E/PSAUHwKnvB3/BSS2P4zQAXBYqSaTB/6MSEBCt/oAN6g9yonF9ejN77pS Ci3rjSWBQN9VR6Xc7DbaKKckMxvB9I+B5ye8HtznDhzcSCxTCEe1joR/y9XJcHxblYVt W3JQesnCZzHrivAuk6z2YpU55YobYtsVei2lsETpaZewZF6RsgYZKoBa5EO2uyFMVkiG NnsA== X-Gm-Message-State: ACgBeo3Mesdi2KspUUSn30ik5NPsK1/ZraGL/YowOVyEs9QtJw68+xE0 nQ7vNiWOnBeb7Mpx0emu8hE= X-Google-Smtp-Source: AA6agR5ewCNy9F+q8FAPPV2JuMBq7E35ydIBDWEqmJhjsir4JqdKjtpA6P9Nw0uNlVJtU8RmTWHvrA== X-Received: by 2002:a17:907:1629:b0:730:7ad7:24f2 with SMTP id hb41-20020a170907162900b007307ad724f2mr10163420ejc.261.1661081341112; Sun, 21 Aug 2022 04:29:01 -0700 (PDT) Received: from gmail.com (195-38-113-151.pool.digikabel.hu. [195.38.113.151]) by smtp.gmail.com with ESMTPSA id jv16-20020a170907769000b0073d6ab5bcaasm1596941ejc.212.2022.08.21.04.28.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Aug 2022 04:29:00 -0700 (PDT) Sender: Ingo Molnar Date: Sun, 21 Aug 2022 13:28:58 +0200 From: Ingo Molnar To: Mel Gorman Cc: Linus Torvalds , David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Andrew Morton , Greg Kroah-Hartman , Axel Rasmussen , Peter Xu , Hugh Dickins , Andrea Arcangeli , Matthew Wilcox , Vlastimil Babka , John Hubbard , Jason Gunthorpe , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt Subject: Re: [PATCH v2] sched/all: Change all BUG_ON() instances in the scheduler to WARN_ON_ONCE() Message-ID: References: <20220808073232.8808-1-david@redhat.com> <1a48d71d-41ee-bf39-80d2-0102f4fe9ccb@redhat.com> <20220815144143.zjsiamw5y22bvgki@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220815144143.zjsiamw5y22bvgki@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mel Gorman wrote: > For the rest, I didn't see obvious recovery paths that would allow the > system to run predictably. Any of them firing will have unpredictable > consequences (e.g. move_queued_task firing would be fun if it was a > per-cpu kthread). Depending on which warning triggers, the remaining life > of the system may be very short but maybe long enough to be logged even > if system locks up shortly afterwards. Correct. I'd prefer to keep all these warnings 'simple' - i.e. no attempted recovery & control flow, unless we ever expect these to trigger. I.e. instead of adding a 'goto' I'd prefer if we removed most of the ones you highlighted. But wanted to keep this first patch simple. Thanks, Ingo