linux-kernel - Re: [RFC][PATCH 1/4] checkpoint-restart: general infrastructure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1218289165.19082.74.camel@nimitz>
Date:	Sat, 09 Aug 2008 06:39:25 -0700
From:	Dave Hansen <dave@...ux.vnet.ibm.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	containers@...ts.linux-foundation.org,
	Theodore Tso <tytso@....edu>, linux-kernel@...r.kernel.org,
	Oren Laadan <orenl@...columbia.edu>
Subject: Re: [RFC][PATCH 1/4] checkpoint-restart: general infrastructure

On Sat, 2008-08-09 at 08:37 +0200, Arnd Bergmann wrote:
> On Saturday 09 August 2008, Dave Hansen wrote:
> > On Sat, 2008-08-09 at 00:39 +0200, Arnd Bergmann wrote:
> > > The main problem I see with that would be atomicity: If you want multiple
> > > processes to keep interacting with each other, you need to save them at
> > > the same point in time, which gets harder as you split your interface into
> > > more than a single file descriptor.
> > 
> > It could take ages to write out a checkpoint even to a single fd, so I
> > suspect we'd have the exact same kinds of issues either way.
> 
> I guess either way, you have to SIGSTOP (or similar) all the tasks you want
> to checkpoint atomically before you start saving the contents.
> If you use a single fd, you can do that under the covers, when using a 
> more complex file system, it seems more logical to require an explicit
> interface for this.

Oh, we're already working on patches to the freezer code to do this for
us.  There's a branch in here from Matt H. that's doing just that:

http://git.kernel.org/?p=linux/kernel/git/daveh/linux-2.6-next-lxc.git;a=shortlog

-- Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/