linux-kernel - Re: cpuset trouble after hibernate

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]

Date:	Mon, 10 Sep 2007 11:45:10 +0200 (CEST)
From:	Simon Derr <Simon.Derr@...l.net>
To:	Nicolas Capit <nicolas.capit@...g.fr>
Cc:	linux-kernel@...r.kernel.org, Paul Jackson <pj@....com>
Subject: Re: cpuset trouble after hibernate

On Sat, 8 Sep 2007, Nicolas Capit wrote:

> Hello,
> 
> This is my situation:
>   - I mounted the pseudo cpuset filesystem into /dev/cpuset
>   - I created a cpuset named oar with my 2 cpus
> 
> cat /dev/cpuset/oar/cpus 
> 0-1
> 
>   - Then I hibernate my computer with 'echo -n "disk" >/sys/power/state'
>   - After reboot:
> 
> cat /dev/cpuset/oar/cpus 
> 0
> 
> Why did I lost a cpu?
> Is this a normal behavior???

Hi Nicolas,

I believe this is related to the fact that hibernation uses the hotplug 
subsystem to disable all CPUs except the boot CPU.

Thus guarantee_online_cpus() is called on each cpuset and removes all 
CPUs, except CPU 0, from all cpusets.

I'm not quite sure about if/how this should be fixed in the kernel, 
though. Looks like a very simple user-land workaround would be enough.

	Simon.

-
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/