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Date: Fri, 18 Jun 2010 09:52:36 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: [Qemu-devel] Re: [PATCH V4 2/3] qemu: Generic task offloading
	framework: threadlets
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To: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>, ego@in.ibm.com, Qemu-development List <qemu-devel@nongnu.org>, Corentin Chary <corentin.chary@gmail.com>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

On 06/17/2010 08:05 PM, Anthony Liguori wrote:
> On 06/17/2010 05:09 AM, Paolo Bonzini wrote:
>>>>> + while (QTAILQ_EMPTY(&(queue->request_list))&&
>>>>> + (ret != ETIMEDOUT)) {
>>>>> + ret = qemu_cond_timedwait(&(queue->cond),
>>>>> + &(queue->lock), 10*100000);
>>>>> + }
>>>>
>>>> Using qemu_cond_timedwait is a hack for not properly broadcasting the
>>>> condvar in flush_threadlet_queue.
>>>
>>> I think Anthony answered this one.
>>
>> I think he said that the code has been changed so I am right? :)
>
> You're right about the condition we check in the exit path but the
> timedwait is needed to expire an idle thread.

In posix-aio-compat, yes.  In threadlets you'll expire excess idle 
threads after each threadlet has completed.  If you want to keep the 
threads above the min_threads-th ready for 10 seconds, that's fine; but 
it's not what the v4 code does.

Paolo