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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4F52EC83007 for ; Wed, 29 Apr 2020 11:54:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24A972073E for ; Wed, 29 Apr 2020 11:54:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726817AbgD2Ly3 (ORCPT ); Wed, 29 Apr 2020 07:54:29 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:48045 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726519AbgD2Ly1 (ORCPT ); Wed, 29 Apr 2020 07:54:27 -0400 X-IronPort-AV: E=Sophos;i="5.73,331,1583164800"; d="scan'208";a="90776572" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 29 Apr 2020 19:54:25 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 822844BCC88B; Wed, 29 Apr 2020 19:54:18 +0800 (CST) Received: from [10.167.220.69] (10.167.220.69) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 29 Apr 2020 19:54:18 +0800 Message-ID: <5EA96AE8.6000707@cn.fujitsu.com> Date: Wed, 29 Apr 2020 19:54:16 +0800 From: Xiao Yang User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.2; zh-CN; rv:1.9.2.18) Gecko/20110616 Thunderbird/3.1.11 MIME-Version: 1.0 To: Steven Rostedt CC: "Joel Fernandes (Google)" , , Ingo Molnar Subject: Re: [PATCH] kernel/trace: Stop and wait for kthread on preempt irq module unload References: <20200424223630.224895-1-joel@joelfernandes.org> <5EA80319.7080005@cn.fujitsu.com> <20200428104409.0995ceb0@gandalf.local.home> <20200428104543.3926eaaf@gandalf.local.home> In-Reply-To: <20200428104543.3926eaaf@gandalf.local.home> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.220.69] X-ClientProxiedBy: G08CNEXCHPEKD05.g08.fujitsu.local (10.167.33.203) To G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) X-yoursite-MailScanner-ID: 822844BCC88B.AAFA2 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: yangx.jy@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/4/28 22:45, Steven Rostedt wrote: > 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; >> } >> Hi Steven, Thanks for your patch. I also used the following steps to do test and didn't get any warning/panic after applying your patch. --------------------------------- for i in $(seq 1 100); do modprobe preemptirq_delay_test test_mode=irq delay=500000; rmmod preemptirq_delay_test; done for i in $(seq 1 100); do modprobe preemptirq_delay_test test_mode=preempt delay=500000; rmmod preemptirq_delay_test; done --------------------------------- But I am not sure which fix(from you and Joel) is better. Thanks, Xiao Yang