4BSD process starvation during I/O
Scott Long
scottl at samsco.org
Thu Nov 24 00:41:23 GMT 2005
David Xu wrote:
> Kris Kennaway wrote:
>
>> On Thu, Nov 24, 2005 at 07:52:30AM +0800, David Xu wrote:
>>
>>
>>> Kris Kennaway wrote:
>>>
>>>
>>>
>>>> Perhaps this can be tweaked.
>>>>
>>>> Kris
>>>>
>>>> P.S. Please, no responses about how maybe someone could write a new
>>>> scheduler that doesn't have this property.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>> Can you try it again with FULL_PREEMPTION is turned on ?
>>>
>>
>>
>> Didn't really make a difference:
>>
>>
>>
> This might only can be fixed when msleep no longer explicitly fiddles
> thread priority, let scheduler fully control it.
>
I don't agree. The more likely problem according Stephan is that
threads returning from userland get their priority elevated so they have
a better chance of running right away. If you have plans to change how
tsleep and msleep manage priorities, please discuss it on arch@ before
you start making changes.
Scott
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