Subject: Re: Overview of concurrency managed workqueue
From: Daniel Walker <dwalker@codeaurora.org>
To: Tejun Heo <tj@kernel.org>
Cc: mingo@elte.hu, awalls@radix.net, linux-kernel@vger.kernel.org,
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Date: Wed, 16 Jun 2010 07:05:46 -0700
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On Wed, 2010-06-16 at 15:45 +0200, Tejun Heo wrote:
> On 06/16/2010 03:41 PM, Daniel Walker wrote:
> > Any workqueue that has a thread which can be prioritized from userspace.
> > As long as there is a thread it can usually be given a priority from
> > userspace, so any _current_ workqueue which uses a single thread or
> > multiple threads is an example of what I'm talking about.
> 
> Eh... what's the use case for that?  That's just so wrong.  What do
> you do after a suspend/resume cycle?  Reprioritize all of them from
> suspend/resume hooks?

The use case is any situation when the user wants to give higher
priority to some set of work items, and there's nothing wrong with that.
In fact there has been a lot of work in the RT kernel related to
workqueue prioritization ..

suspend/resume shouldn't touch the thread priorities unless your tearing
down the threads and remaking them each suspend/resume cycle from inside
the kernel.

Daniel

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