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=-12.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 7F0B9C433E6 for ; Fri, 19 Feb 2021 21:23:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C383614A7 for ; Fri, 19 Feb 2021 21:23:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229799AbhBSVXS (ORCPT ); Fri, 19 Feb 2021 16:23:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:48700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbhBSVXR (ORCPT ); Fri, 19 Feb 2021 16:23:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id F148D64E4B; Fri, 19 Feb 2021 21:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613769756; bh=V9ROP9BTU2xPPUZvYOXMkvnIE3PpDLZs4WcqEFNzXMg=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=noxUnBnIZsOFQTn2oToKV3Mzsq08CfvAmbEtvTr3lFeFF76Jso7mWpkrSi2NK35e9 N442QCPPDn9yUS8GUtMA4bN83nk3mW6dqn/rDCP3nlpDSkMd7W3as7hKUYdDyYgb9a REeuTX3sOofttgNd9Gl3z4s5DAusYUJNvwrQWdWGce8Y7QG1s/Fm3VhjIRw2sVVuYh 9lbvGffTWK9dNpdK6B3le3YO8FRPMEO4mpgXK3d53LW8vFuXUWHIf8EfqCt5VfufUI Dk/wZWgE5j2azkk3uTXHdusSFsXHbumI5BzdP2aBEr2if+qaW4t6Eoa5J0W6nvfft2 zemMRctPLxKXQ== Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 869F23520E6A; Fri, 19 Feb 2021 13:22:34 -0800 (PST) Date: Fri, 19 Feb 2021 13:22:34 -0800 From: "Paul E. McKenney" To: Steven Rostedt Cc: Uladzislau Rezki , Sebastian Andrzej Siewior , Masami Hiramatsu , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , LKML , RCU , Michael Ellerman , Andrew Morton , Daniel Axtens , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Michal Hocko , "Theodore Y . Ts'o" , Oleksiy Avramchenko Subject: Re: [PATCH] kprobes: Fix to delay the kprobes jump optimization Message-ID: <20210219212234.GC2743@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20210219081755.eucq4srbam6wg2gm@linutronix.de> <20210219104958.GA34308@pc638.lan> <20210219105710.d626zexj6vzt6k6y@linutronix.de> <20210219111301.GA34441@pc638.lan> <20210219111738.go6i2fdzvavpotxd@linutronix.de> <20210219112357.GA34462@pc638.lan> <20210219112751.GA34528@pc638.lan> <20210219181811.GY2743@paulmck-ThinkPad-P72> <20210219183336.GA23049@paulmck-ThinkPad-P72> <20210219150231.31dc72a2@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210219150231.31dc72a2@gandalf.local.home> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 19, 2021 at 03:02:31PM -0500, Steven Rostedt wrote: > On Fri, 19 Feb 2021 10:33:36 -0800 > "Paul E. McKenney" wrote: > > > commit 4f659bf04fc4610523544493d6db92fc8670b086 > > Author: Paul E. McKenney > > Date: Fri Feb 12 16:20:40 2021 -0800 > > > > softirq: Don't try waking ksoftirqd before it has been spawned > > > > If there is heavy softirq activity, the softirq system will attempt > > to awaken ksoftirqd and will stop the traditional back-of-interrupt > > softirq processing. This is all well and good, but only if the > > ksoftirqd kthreads already exist, which is not the case during early > > boot, in which case the system hangs. > > > > One reproducer is as follows: > > > > tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 2 --configs "TREE03" --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --bootargs "threadirqs=1" --trust-make > > > > This commit therefore adds a couple of existence checks for ksoftirqd > > and forces back-of-interrupt softirq processing when ksoftirqd does not > > yet exist. With this change, the above test passes. > > > > Reported-by: Sebastian Andrzej Siewior > > Reported-by: Uladzislau Rezki > > Signed-off-by: Paul E. McKenney > > Hmm, I wonder if this is what patchwork picked up regarding the > reported-by. > > And I checked, it did not add the "Signed-off-by" from you to Masami's > patch ;-) > > The dangers of posting patches in threads of other patches :-/ Glad I asked, then! ;-) Thanx, Paul