From: Tejun Heo <tj@kernel.org>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: linux-kernel@vger.kernel.org, Andrew Vagin <avagin@parallels.com>,
Pavel Emelyanov <xemul@parallels.com>,
James Bottomley <jbottomley@parallels.com>,
Glauber Costa <glommer@parallels.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
Dave Hansen <dave@linux.vnet.ibm.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Daniel Lezcano <dlezcano@fr.ibm.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>
Subject: Re: [patch 5/5] elf: Add support for loading ET_CKPT files
Date: Fri, 14 Oct 2011 10:33:04 -0700 [thread overview]
Message-ID: <20111014173304.GD4294@google.com> (raw)
In-Reply-To: <20111014171033.GC4294@google.com>
Hello, again.
On Fri, Oct 14, 2011 at 10:10:33AM -0700, Tejun Heo wrote:
> I see that you removed zapping to allow restoring multi-threaded
> process, which seems quite scary to me. It might be okay, I don't
> know, but IMHO it just isn't a very good idea to introduce such
> variation to basic exec behavior for this rather narrow use case.
* It's still calling exec_mmap(), so the exec'ing thread will be on
the new mm while other threads would still be on the old one.
* There are operations which assume that the calling task is
de-threaded and thus has exclusive access to data structures which
can be shared among the thread group (e.g. signal struct). How are
accesses to them synchronized?
* What about properties which should be reset and then shared by
threads by inheriting (credentials, comm, self_exec_id and so on)?
e.g. new thread follows exec-time imposed rules but old ones keep
their original credentials.
So, no, it really doesn't look good.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-10-14 17:33 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-14 11:04 [patch 0/5] [RFC] Checkpoint/restore and Elf extension Cyrill Gorcunov
2011-10-14 11:04 ` [patch 1/5] proc: Introduce the Children: line in /proc/<pid>/status Cyrill Gorcunov
2011-10-14 16:36 ` Tejun Heo
2011-10-14 11:04 ` [patch 2/5] fs: Add do_close helper Cyrill Gorcunov
2011-10-14 11:04 ` [patch 3/5] fs, proc: Add /proc/$pid/tls entry Cyrill Gorcunov
2011-10-14 16:40 ` Tejun Heo
2011-10-14 16:43 ` Cyrill Gorcunov
2011-10-14 11:04 ` [patch 4/5] fs, proc: Add start_data, end_data, start_brk members to /proc/$pid/stat Cyrill Gorcunov
2011-10-14 11:04 ` [patch 5/5] elf: Add support for loading ET_CKPT files Cyrill Gorcunov
2011-10-14 17:10 ` Tejun Heo
2011-10-14 17:33 ` Tejun Heo [this message]
2011-10-19 9:03 ` Pavel Emelyanov
2011-10-19 18:22 ` Tejun Heo
2011-10-19 18:49 ` Cyrill Gorcunov
2011-10-19 18:52 ` Cyrill Gorcunov
2011-10-19 18:53 ` Tejun Heo
2011-10-19 19:56 ` Cyrill Gorcunov
2011-10-21 18:26 ` Tejun Heo
2011-10-21 18:36 ` Cyrill Gorcunov
2011-10-21 18:42 ` Cyrill Gorcunov
2011-10-21 18:48 ` Tejun Heo
2011-10-21 18:53 ` Cyrill Gorcunov
2011-10-22 6:34 ` Pavel Emelyanov
2011-10-20 8:33 ` Pavel Emelyanov
2011-10-20 15:56 ` Tejun Heo
2011-10-20 16:04 ` Cyrill Gorcunov
2011-10-20 17:30 ` Pavel Emelyanov
2011-10-15 18:59 ` Cyrill Gorcunov
2011-10-21 11:06 ` Glauber Costa
2011-10-21 11:20 ` Cyrill Gorcunov
2011-10-21 11:21 ` Glauber Costa
2011-10-21 11:35 ` Cyrill Gorcunov
2011-10-22 16:49 ` Dan Merillat
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