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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8A912C43603 for ; Tue, 17 Dec 2019 15:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AEF821582 for ; Tue, 17 Dec 2019 15:30:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728315AbfLQPau (ORCPT ); Tue, 17 Dec 2019 10:30:50 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:46608 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728118AbfLQPau (ORCPT ); Tue, 17 Dec 2019 10:30:50 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihEo9-00065R-R5; Tue, 17 Dec 2019 15:30:45 +0000 Date: Tue, 17 Dec 2019 15:30:45 +0000 From: Al Viro To: qiwuchen55@gmail.com Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, chenqiwu Subject: Re: [RESEND PATCH] fput: Use unbound workqueue for scheduling delayed fput works Message-ID: <20191217153045.GZ4203@ZenIV.linux.org.uk> References: <1576595472-27341-1-git-send-email-qiwuchen55@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1576595472-27341-1-git-send-email-qiwuchen55@gmail.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Dec 17, 2019 at 11:11:12PM +0800, qiwuchen55@gmail.com wrote: > From: chenqiwu > > There is a potential starvation that the number of delayed fput works > increase rapidly if task exit storm or fs unmount issue happens. Err... Details, please, ideally along with a reproducer. In particular, I would like to understand what does any of that have to do with umount. Or to task exits, for that matter - exit_files() is called before exit_task_work(), so you shouldn't normally be seeing task_work_add() failures when files get closed on exit(2)... If you are really observing such problems, it might be worth looking into the underlying situation - something odd appears to be going on and I'd rather understand what it is.