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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham 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 18F91C83000 for ; Tue, 28 Apr 2020 14:44:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3258206D7 for ; Tue, 28 Apr 2020 14:44:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbgD1OoM (ORCPT ); Tue, 28 Apr 2020 10:44:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:41824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727803AbgD1OoM (ORCPT ); Tue, 28 Apr 2020 10:44:12 -0400 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 5B23E206C0; Tue, 28 Apr 2020 14:44:11 +0000 (UTC) Date: Tue, 28 Apr 2020 10:44:09 -0400 From: Steven Rostedt To: Xiao Yang Cc: "Joel Fernandes (Google)" , , Ingo Molnar Subject: Re: [PATCH] kernel/trace: Stop and wait for kthread on preempt irq module unload Message-ID: <20200428104409.0995ceb0@gandalf.local.home> In-Reply-To: <5EA80319.7080005@cn.fujitsu.com> References: <20200424223630.224895-1-joel@joelfernandes.org> <5EA80319.7080005@cn.fujitsu.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Apr 2020 18:19:05 +0800 Xiao Yang wrote: > Hi Joel, > > Thanks for your quick fix. > > Unfortunately, it fixes my original panic but introduces other > issues(two wanings and one panic) on my arm64 vm, as below: > Does the following on top of Joel's patch fix it? -- Steve diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c index 1c28ca20e30b..6d9131ae7e8c 100644 --- a/kernel/trace/preemptirq_delay_test.c +++ b/kernel/trace/preemptirq_delay_test.c @@ -113,15 +113,27 @@ static int preemptirq_delay_run(void *data) for (i = 0; i < s; i++) (testfuncs[i])(i); + + while (!kthread_should_stop()) { + schedule(); + set_current_state(TASK_INTERRUPTIBLE); + } + + __set_current_state(TASK_RUNNING); + return 0; } static struct task_struct *preemptirq_start_test(void) { + struct task_struct *task; char task_name[50]; snprintf(task_name, sizeof(task_name), "%s_test", test_mode); - return kthread_run(preemptirq_delay_run, NULL, task_name); + task = kthread_run(preemptirq_delay_run, NULL, task_name); + if (IS_ERR(task)) + return NULL; + return task; }