netdev - Re: [PATCH 3/3] vhost: apply cpumask and cgroup to vhost workers

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:	Tue, 01 Jun 2010 12:56:33 +0200
From:	Tejun Heo <tj@...nel.org>
To:	"Michael S. Tsirkin" <mst@...hat.com>
CC:	Oleg Nesterov <oleg@...hat.com>,
	Sridhar Samudrala <sri@...ibm.com>,
	netdev <netdev@...r.kernel.org>,
	lkml <linux-kernel@...r.kernel.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Dmitri Vorobiev <dmitri.vorobiev@...ial.com>,
	Jiri Kosina <jkosina@...e.cz>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>, Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH 3/3] vhost: apply cpumask and cgroup to vhost workers

Hello,

On 06/01/2010 12:17 PM, Michael S. Tsirkin wrote:
> Something that I wanted to figure out - what happens if the
> CPU mask limits us to a certain CPU that subsequently goes offline?

The thread gets unbound during the last steps of cpu offlining.

> Will e.g. flush block forever or until that CPU comes back?
> Also, does singlethreaded workqueue behave in the same way?

So, things will proceed as usual although the thread will lose its
affinity.  Singlethread wqs don't bind their workers (and they
shouldn't! :-).  MT ones explicitly manage workers according to cpu
up/down events.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html