From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754091AbaCJRr2 (ORCPT ); Mon, 10 Mar 2014 13:47:28 -0400 Received: from imap.thunk.org ([74.207.234.97]:39460 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753292AbaCJRr0 (ORCPT ); Mon, 10 Mar 2014 13:47:26 -0400 Date: Mon, 10 Mar 2014 13:47:18 -0400 From: "Theodore Ts'o" To: Mike Galbraith Cc: Sebastian Andrzej Siewior , Steven Rostedt , "linux-kernel@vger.kernel.org" , linux-rt-users , tglx@linutronix.de Subject: Re: [PATCH RT] fs: jbd2: pull your plug when waiting for space Message-ID: <20140310174718.GB6763@thunk.org> Mail-Followup-To: Theodore Ts'o , Mike Galbraith , Sebastian Andrzej Siewior , Steven Rostedt , "linux-kernel@vger.kernel.org" , linux-rt-users , tglx@linutronix.de References: <20140221123253.GA12822@linutronix.de> <1392990852.5451.178.camel@marge.simpson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1392990852.5451.178.camel@marge.simpson.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 21, 2014 at 02:54:12PM +0100, Mike Galbraith wrote: > > ext3: dbench1 queues a buffer, blocks on journal mutex, it's plug is not > pulled. dbench2 mutex owner is waiting for kjournald, who is waiting for > the buffer queued by dbench1. Game over. Where is in ext3/4 are we calling some function which could end up blocking on kjournald while we have the I/O queue plugged? That sounds suspicious and potentially wrong. - Ted