Message-ID: <4C1C8B32.1040007@kernel.org>
Date: Sat, 19 Jun 2010 11:17:38 +0200
From: Tejun Heo <tj@kernel.org>
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To: Andi Kleen <andi@firstfloor.org>
CC: Andy Walls <awalls@md.metrocast.net>,
       Daniel Walker <dwalker@codeaurora.org>, mingo@elte.hu,
       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
Subject: Re: Overview of concurrency managed workqueue
References: <1276695665.9309.17.camel@m0nster> <4C18D574.1040903@kernel.org> <1276697146.9309.27.camel@m0nster> <1276776066.2461.15.camel@localhost> <87vd9fo1sk.fsf@basil.nowhere.org> <4C1C8263.9040404@kernel.org> <87fx0jo0z6.fsf@basil.nowhere.org> <4C1C8772.8090406@kernel.org> <20100619090851.GF18946@basil.fritz.box> <4C1C8A18.2030709@kernel.org> <20100619091518.GG18946@basil.fritz.box>
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Hello,

On 06/19/2010 11:15 AM, Andi Kleen wrote:
>> Well, in general, queueing to execution latency should be fairly low
>> especially if it's put at the front of the queue but well it's nothing
>> with any kind of guarantee.
> 
> This is not a hard real time situation with a hard deadline,
> just "ASAP"
> 
>> I'm currently writing a kthread wrapper which basically provides
>> similar interface to wq but guarantees binding to a specific thread
>> which can be RT of course.  If single threadedness is acceptable, I
>> think this would render better behavior.  What do you think?
> 
> I think I would prefer simply high priority, but normal work item.
> 
> Otherwise we have the thread hanging around all the time 
> and on a large system it's still only a single one, so
> it'll never scale.

Hmmm... yeah, adding it isn't hard.  I'm just a bit skeptical how
useful it would be.  Having only single user would be a bit silly.
Can you think of anything else which could benefit from high priority
queueing?

Thanks.

-- 
tejun
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