From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932095AbZBLWLl (ORCPT ); Thu, 12 Feb 2009 17:11:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753455AbZBLWLb (ORCPT ); Thu, 12 Feb 2009 17:11:31 -0500 Received: from fg-out-1718.google.com ([72.14.220.155]:36785 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753083AbZBLWL3 (ORCPT ); Thu, 12 Feb 2009 17:11:29 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=g/oKFL9VTgsDx4z2SCb+ps5M8KIaCgILJan4lDcg4RAz0Dv3G+AOXruylecKg7OZVF pW8RnJ1DYw6MXQ8x1DwfWkcB56RJGu6yPK6cPoMjJAkkw65pJLZAaJLsGUky0Z4GG38/ TRucpWu/GWhzbWNC8WgKREVlG3wD1Ca1Ts130= Date: Fri, 13 Feb 2009 01:17:41 +0300 From: Alexey Dobriyan To: Dave Hansen Cc: Andrew Morton , Matt Mackall , containers@lists.linux-foundation.org, hpa@zytor.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, viro@zeniv.linux.org.uk, linux-api@vger.kernel.org, mingo@elte.hu, torvalds@linux-foundation.org, tglx@linutronix.de, Pavel Emelyanov Subject: Re: What can OpenVZ do? Message-ID: <20090212221741.GA13861@x200.localdomain> References: <1233076092-8660-1-git-send-email-orenl@cs.columbia.edu> <1234285547.30155.6.camel@nimitz> <20090211141434.dfa1d079.akpm@linux-foundation.org> <1234462282.30155.171.camel@nimitz> <1234467035.3243.538.camel@calx> <20090212114207.e1c2de82.akpm@linux-foundation.org> <1234475483.30155.194.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234475483.30155.194.camel@nimitz> 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 Thu, Feb 12, 2009 at 01:51:23PM -0800, Dave Hansen wrote: > On Thu, 2009-02-12 at 11:42 -0800, Andrew Morton wrote: > > On Thu, 12 Feb 2009 13:30:35 -0600 > > Matt Mackall wrote: > > > > > On Thu, 2009-02-12 at 10:11 -0800, Dave Hansen wrote: > > > > > > > > - In bullet-point form, what features are missing, and should be added? > > > > > > > > * support for more architectures than i386 > > > > * file descriptors: > > > > * sockets (network, AF_UNIX, etc...) > > > > * devices files > > > > * shmfs, hugetlbfs > > > > * epoll > > > > * unlinked files > > > > > > > * Filesystem state > > > > * contents of files > > > > * mount tree for individual processes > > > > * flock > > > > * threads and sessions > > > > * CPU and NUMA affinity > > > > * sys_remap_file_pages() > > > > > > I think the real questions is: where are the dragons hiding? Some of > > > these are known to be hard. And some of them are critical checkpointing > > > typical applications. If you have plans or theories for implementing all > > > of the above, then great. But this list doesn't really give any sense of > > > whether we should be scared of what lurks behind those doors. > > > > How close has OpenVZ come to implementing all of this? I think the > > implementatation is fairly complete? > > I also believe it is "fairly complete". At least able to be used > practically. > > > If so, perhaps that can be used as a guide. Will the planned feature > > have a similar design? If not, how will it differ? To what extent can > > we use that implementation as a tool for understanding what this new > > implementation will look like? > > Yes, we can certainly use it as a guide. However, there are some > barriers to being able to do that: > > dave@nimitz:~/kernels/linux-2.6-openvz$ git diff v2.6.27.10... | diffstat | tail -1 > 628 files changed, 59597 insertions(+), 2927 deletions(-) > dave@nimitz:~/kernels/linux-2.6-openvz$ git diff v2.6.27.10... | wc > 84887 290855 2308745 git-diff -- kernel/cpt/ should give more realistic picture. > Unfortunately, the git tree doesn't have that great of a history. It > appears that the forward-ports are just applications of huge single > patches which then get committed into git. This tree has also > historically contained a bunch of stuff not directly related to > checkpoint/restart like resource management. > We'd be idiots not to take a hard look at what has been done in OpenVZ. > But, for the time being, we have absolutely no shortage of things that > we know are important and know have to be done. Our largest problem is > not finding things to do, but is our large out-of-tree patch that is > growing by the day. :(