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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BAD6C25B06 for ; Thu, 11 Aug 2022 21:28:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8DDEE6B0073; Thu, 11 Aug 2022 17:28:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 88C1B6B0075; Thu, 11 Aug 2022 17:28:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77B728E0001; Thu, 11 Aug 2022 17:28:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 62E046B0073 for ; Thu, 11 Aug 2022 17:28:47 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 27DCFC0360 for ; Thu, 11 Aug 2022 21:28:47 +0000 (UTC) X-FDA: 79788601494.27.02AC28A Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf29.hostedemail.com (Postfix) with ESMTP id D7572120186 for ; Thu, 11 Aug 2022 21:28:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VU1PZeaw6I4YyL6iOFs+wCjPWpBvnmOGKLSrFWd0G/s=; b=QG7bP6FilsSAZ571eM1Q1YCap/ VairpPnmpDhpHxSQR4JS2J4Z5dAqMi3Un8zuDp5WS0PbP1J8VXlrX7PfxIAVNcyI9XmqSCq22gPe7 SfTw9evl2A6qLn4poujnmCxcYlJlceCXSwEzvzlV4sAT6WN3LL0gvtXjwB6aep7QK18YbwO7iwCf1 0l9DxZcYbik86ikCHjgWVeXU/j5jyiBpdautmducKWbre7hkqkwLao4BRUawDVVXOVWOr6H+p39Y8 hoOiHExMgtVPHTWNiPuN5DJJOwYodocQ25wXfybxbHaupoN5bL8C0m9HEn1fUnWr6K2KZZmaSBgnB QYLqbiuA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oMFj9-001IJD-45; Thu, 11 Aug 2022 21:28:27 +0000 Date: Thu, 11 Aug 2022 22:28:27 +0100 From: Matthew Wilcox To: Linus Torvalds Cc: Ingo Molnar , 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 , Vlastimil Babka , John Hubbard , Jason Gunthorpe , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Mel Gorman Subject: Re: [PATCH] sched/all: Change BUG_ON() instances to WARN_ON() Message-ID: References: <20220808073232.8808-1-david@redhat.com> <1a48d71d-41ee-bf39-80d2-0102f4fe9ccb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=QG7bP6Fi; dmarc=none; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660253326; a=rsa-sha256; cv=none; b=FOU6UTR8dnSE8KGbvIZucY+PzxlDIGPZq+hyZXJ2KE2PwInQAW992zSWCwlR7m1Y5zsVuC gKObsqH6y1Yc1NU4UnWKgnFAcikbrDM3lEJ6q1xz8eeYqsXoGMnbGlRcatFmD0f7PN/R4D m5npsGO2E7HU/GHWjKRGOu/ySH49jOw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660253326; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=VU1PZeaw6I4YyL6iOFs+wCjPWpBvnmOGKLSrFWd0G/s=; b=JpjJ1bIY7f8pFFlkM5PI+ULyoQKH8oUOenm2wlVpp2QRMtp9LcAaeeRfuO8JgR4k1AQn+G +hiczgeHvsS3EA1lVwcDaSN0wO1A2C51BQf4+bk2netX3lAsgBBnGfE5GYAaKN0JOpU4Ul nqEXtuWKp5SyP0pRq0QuXgo9bkU39T0= X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=QG7bP6Fi; dmarc=none; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: uxnpijhxms99fcxz9z8taatuffb4cqyn X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: D7572120186 X-HE-Tag: 1660253325-963738 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Aug 11, 2022 at 01:43:09PM -0700, Linus Torvalds wrote: > May I suggest going one step further, and making these WARN_ON_ONCE() instead. > > >From personal experience, once some scheduler bug (or task struct > corruption) happens, ti often *keeps* happening, and the logs just > fill up with more and more data, to the point where you lose sight of > the original report (and the machine can even get unusable just from > the logging). I've been thinking about magically turning all the WARN_ON_ONCE() into (effectively) WARN_ON_RATELIMIT(). I had some patches in that direction a while ago but never got round to tidying them up for submission.