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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 2E9EAC433DF for ; Fri, 3 Jul 2020 08:11:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13EFA206A1 for ; Fri, 3 Jul 2020 08:11:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbgGCILj (ORCPT ); Fri, 3 Jul 2020 04:11:39 -0400 Received: from mx2.suse.de ([195.135.220.15]:43364 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725648AbgGCILj (ORCPT ); Fri, 3 Jul 2020 04:11:39 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 746D6B5E7; Fri, 3 Jul 2020 08:11:38 +0000 (UTC) Date: Fri, 3 Jul 2020 10:11:36 +0200 From: Petr Mladek To: qiang.zhang@windriver.com Cc: ben.dooks@codethink.co.uk, bfields@redhat.com, cl@rock-chips.com, peterz@infradead.org, tj@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kthread: work could not be queued when worker being destroyed Message-ID: <20200703081136.GD11587@alley> References: <20200702044946.33142-1-qiang.zhang@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200702044946.33142-1-qiang.zhang@windriver.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 2020-07-02 12:49:46, qiang.zhang@windriver.com wrote: > From: Zhang Qiang > > The queuing_blocked func should returns true when the worker > being destroyed. Queuing work when the worker is not running usually means a bad design on the API user side. The work is never done and some job has not finished correctly. We should not go over it quietly. > Signed-off-by: Zhang Qiang > --- > kernel/kthread.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 1166f2043e67..2ca711d0e78a 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -791,7 +791,7 @@ static inline bool queuing_blocked(struct kthread_worker *worker, > { > lockdep_assert_held(&worker->lock); A better solution would be: if (WARN_ON(!worker->task) return true; > - return !list_empty(&work->node) || work->canceling; > + return !list_empty(&work->node) || work->canceling || !worker->task; > } > > static void kthread_insert_work_sanity_check(struct kthread_worker *worker, Best Regards, Petr