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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 00133C433E0 for ; Fri, 19 Feb 2021 20:03:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC20264EB3 for ; Fri, 19 Feb 2021 20:03:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230038AbhBSUDV (ORCPT ); Fri, 19 Feb 2021 15:03:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:33686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229765AbhBSUDP (ORCPT ); Fri, 19 Feb 2021 15:03:15 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7B5BD64D9C; Fri, 19 Feb 2021 20:02:32 +0000 (UTC) Date: Fri, 19 Feb 2021 15:02:31 -0500 From: Steven Rostedt To: "Paul E. McKenney" 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: <20210219150231.31dc72a2@gandalf.local.home> In-Reply-To: <20210219183336.GA23049@paulmck-ThinkPad-P72> References: <161365856280.719838.12423085451287256713.stgit@devnote2> <20210218151554.GQ2743@paulmck-ThinkPad-P72> <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> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 :-/ -- Steve