From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753983Ab0CZN57 (ORCPT ); Fri, 26 Mar 2010 09:57:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58102 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753812Ab0CZN56 (ORCPT ); Fri, 26 Mar 2010 09:57:58 -0400 Date: Fri, 26 Mar 2010 14:56:22 +0100 From: Oleg Nesterov To: Matt Helsley Cc: Grzegorz Nosek , Roland McGrath , Sukadev Bhattiprolu , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: Testing lxc 0.6.5 in Fedora 13 Message-ID: <20100326135622.GC15790@redhat.com> References: <20100321195044.GA23757@megiteam.pl> <20100323212834.GH20796@count0.beaverton.ibm.com> <20100325213356.GB20541@megiteam.pl> <20100326111131.GA8604@redhat.com> <20100326115357.GA3345@count0.beaverton.ibm.com> <20100326124522.GD17113@megiteam.pl> <20100326125459.GD3345@count0.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100326125459.GD3345@count0.beaverton.ibm.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 On 03/26, Matt Helsley wrote: > > That said there are > plenty of #ifdefs in strace and patching it to use GETEVENTMSG is quite > a small patch. Not really, unless I missed something. See my another email, strace doesn't even use the notification from do_fork(), not only it doesn't read ->ptrace_message. > However, as I said, that still doesn't "fix" strace so that it can > be used to trace tasks in child pid namespaces. Yes. Looks like, the necessary change in kernel is simple (and btw, it is well known fact the reported pid is not ns-friendly). What should be really fixed is strace/etc. > Especially when the > traced tasks are more than one namepace deeper. :( Hmm... I guess, you mean setns() idea? Otherwise, I _think_ that the deeper namepaces are fine wrt pid_nr. > I don't think the kernel provides special out-of-band methods for fetching > pids related to traced tasks except during fork and clone. Not wait*(). Could you clarify? I think wait*() is already namespace-friendly? Oleg.