From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757353AbYGCXBh (ORCPT ); Thu, 3 Jul 2008 19:01:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755900AbYGCXB3 (ORCPT ); Thu, 3 Jul 2008 19:01:29 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:56032 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755883AbYGCXB3 (ORCPT ); Thu, 3 Jul 2008 19:01:29 -0400 Date: Thu, 3 Jul 2008 16:01:17 -0700 From: Andrew Morton To: Hugh Dickins Cc: balbir@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2.6.26-rc8-mm1] memrlimit: fix mmap_sem deadlock Message-Id: <20080703160117.b3781463.akpm@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 3 Jul 2008 21:50:31 +0100 (BST) Hugh Dickins wrote: > "ps -f" hung after "killall make" of make -j20 kernel builds. It's > generally considered bad manners to down_write something you already > have down_read. exit_mm up_reads before calling mm_update_next_owner, > so I guess exec_mmap can safely do so too. (And with that repositioning > there's not much point in mm_need_new_owner allowing for NULL mm.) > thanks > --- > Fix to memrlimit-cgroup-mm-owner-callback-changes-to-add-task-info.patch > quite independent of its recent sleeping-inside-spinlock fix; could even > be applied to 2.6.26, though no deadlock there. Gosh, I see those patches > have spawned "Reviewed-by" tags in my name: sorry, no, just "Bug-found-by". I switched memrlimit-add-memrlimit-controller-accounting-and-control-memrlimit-improve-fork-and-error-handling.patch and memrlimit-cgroup-mm-owner-callback-changes-to-add-task-info-memrlimit-fix-sleep-inside-sleeplock-in-mm_update_next_owner.patch to Cc:you. There doesn't seem to have been much discussion regarding your recent objections to the memrlimit patches. But it caused me to put a big black mark on them. Perhaps sending it all again would be helpful.