From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753411AbaKZXy3 (ORCPT ); Wed, 26 Nov 2014 18:54:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35635 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbaKZXy1 (ORCPT ); Wed, 26 Nov 2014 18:54:27 -0500 Date: Thu, 27 Nov 2014 00:54:16 +0100 From: Oleg Nesterov To: Andrew Morton , "Eric W. Biederman" Cc: Aaron Tomlin , Pavel Emelyanov , Serge Hallyn , Sterling Alexander , linux-kernel@vger.kernel.org Subject: [PATCH v2 0/2] exit/pid_ns: comments + simple fix Message-ID: <20141126235416.GA32688@redhat.com> References: <20141107201424.GA22209@redhat.com> <20141124200602.GA20575@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141124200602.GA20575@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To remind, this doesn't depend on other changes in -mm. It is not clear to me if I addressed Eric's objections or not, but let me send V2 (I reordered these patches). I updated the changelog/comments in 2/2, hopefully now it is more clear that this patch only tries to explain how the current code works, and why do we need to wait for nr_hashed==init_pids from the kernel perspective. Otherwise it is basically the same patch, except I added another note about sys_wait4(). And, Eric, let me repeat. In any case we do not need for EXIT_DEAD tasks. They are stealth. In fact this state should die, it only complicates do_wait/reparenting/etc but we can't avoid it right now (mostly because of the locking in wait paths). IOW. If we could somehow detect that this pid_ns has only EXIT_DEAD tasks we could return and user-space won't notice this change. No, it is not that I think we should do this, but this should be documented. Please review. Oleg.