Subject: Re: Overview of concurrency managed workqueue
From: Daniel Walker <dwalker@codeaurora.org>
To: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Tejun Heo <tj@kernel.org>, mingo@elte.hu, awalls@radix.net,
       linux-kernel@vger.kernel.org, jeff@garzik.org,
       akpm@linux-foundation.org, rusty@rustcorp.com.au,
       cl@linux-foundation.org, dhowells@redhat.com, arjan@linux.intel.com,
       johannes@sipsolutions.net, oleg@redhat.com, axboe@kernel.dk
In-Reply-To: <4C191885.9080303@s5r6.in-berlin.de>
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Date: Wed, 16 Jun 2010 11:41:04 -0700
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On Wed, 2010-06-16 at 20:31 +0200, Stefan Richter wrote:
> Daniel Walker wrote:
> [tweak scheduling priority of a worker thread]
> > Let say I have a high priority
> > thread in userspace , and I discover through analysis that my thread is
> > being forced to wait on a workqueue thread (priority inversion) , so
> > then I just increase the workqueue thread priority to overcome the
> > inversion. That's totally valid, and you don't even need to know exactly
> > what the thread is doing..
> 
> I suspect the _actual_ problem to solve here is not that of proper
> scheduling priorities but that of having to meet deadlines.

I think the workqueue would need to be adjust somehow even in terms of
deadlines. Like you'll miss your deadline unless the workqueue runs.

Daniel

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