Kernel threads inherit CPU affinity from random sibling

[Attilio Rao]

2012/2/24, Eugene Grosbein <egrosbein at rdtc.ru>:
> 28.01.2012 20:22, Attilio Rao пишет:
>
>> 2012/1/28 Ryan Stone <rysto32 at gmail.com>:
>>> On Fri, Jan 27, 2012 at 10:41 PM, Attilio Rao <attilio at freebsd.org>
>>> wrote:
>>>> I think what you found out is very sensitive.
>>>> However, the patch is not correct as you cannot call
>>>> cpuset_setthread() with thread_lock held.
>>>
>>> Whoops!  I actually discovered that for myself and had already fixed
>>> it, but apparently I included an old version of the patch in the
>>> email.
>>>
>>>> Hence this is my fix:
>>>> http://www.freebsd.org/~attilio/cpuset_root.patch
>>>
>>> Oh, I do like this better.  I tried something similar myself but
>>> abandoned it because I misread how sched_affinity() was implemented by
>>> 4BSD(I had gotten the impression that once TSF_AFFINITY is set it
>>> could never be cleared).
>>
>> Do you have a pathological test-case for it? Are you going to test the
>> patch?
>
> I have the pathological test-case for it:
> http://www.freebsd.org/cgi/query-pr.cgi?pr=165444
>

A fix has been committed as r230984, it should apply to STABLE_9/8
too, can you try it?

Attilio


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