linux-kernel - Re: [PATCH 0/2] CGroups: cgroup member list enhancement/fix

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20090713121138.GC5051@balbir.in.ibm.com>
Date:	Mon, 13 Jul 2009 17:41:38 +0530
From:	Balbir Singh <balbir@...ux.vnet.ibm.com>
To:	Paul Menage <menage@...gle.com>
Cc:	lizf@...fujitzu.com, bblum@...gle.com,
	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
	containers@...ts.linux-foundation.org,
	libcg-devel <libcg-devel@...ts.sourceforge.net>
Subject: Re: [PATCH 0/2] CGroups: cgroup member list enhancement/fix

* menage@...gle.com <menage@...gle.com> [2009-07-10 16:58:23]:

> On Sat, Jul 4, 2009 at 11:38 PM, Balbir Singh<balbir@...ux.vnet.ibm.com> wrote:
> >
> > Paul, I don't see an interface to migrate all procs or at-least I
> > can't read it in the changelog. As discussed in the containers
> > mini-summit in 2008, it would be a nice thing to have (I've not looked
> > at the implementation yet).
> >
> 
> We're still working on that bit.
> 
> We want to provide the guarantee that if you write a tgid to the procs
> file, all its threads get migrated even if you race with a clone()
> call, and are trying to figure out a nice way to do that without
> introducing unnecessary overhead/synchronization in the fork path.
>

How about lazy migration? Mark a group as to move when the kernel sees
it next for scheduling. We'll still need synchronization, but we can
amortize the cost. I've not tried it yet. BTW, we have quite a bit of
logic in libcgroup to deal with migration problems, specially during
classification, which Kenichi has added. We needed timestamping to get
correct migration working during classification.

-- 
	Balbir
--
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/