svn commit: r222060 - in user/avg/xcpu/sys: kern sys

[Attilio Rao]

2011/5/18 Andriy Gapon <avg at freebsd.org>:
> on 18/05/2011 21:24 Pawel Jakub Dawidek said the following:
>> On Wed, May 18, 2011 at 03:08:30PM +0000, Andriy Gapon wrote:
>> [...]
>>> --- user/avg/xcpu/sys/sys/proc.h     Wed May 18 15:07:36 2011        (r222059)
>>> +++ user/avg/xcpu/sys/sys/proc.h     Wed May 18 15:08:30 2011        (r222060)
>>> @@ -781,7 +781,7 @@ MALLOC_DECLARE(M_SUBPROC);
>>>   * Otherwise, the kernel will deadlock since the scheduler isn't
>>>   * going to run the thread that holds the lock we need.
>>>   */
>>> -#define     THREAD_PANICED()        \
>>> +#define     TD_IS_INPANIC() \
>>>      (panicstr != NULL && (curthread->td_flags & TDF_INPANIC) != 0)
>>
>> Does TDF_INPANIC make sense without panicstr being set?
>
> Very good observation.  It seems that TDF_INPANIC can never be set unless
> panicstr is set.  So, I guess it should be OK to simplify the macro further.
> Thank you.

However I think that TDF_INPANIC handling is not optimal.
You should really acquire thread_lock otherwise you are going to break
choosethread() concurrency.

I would prefer to make TDF_INPANIC a private flag and just use it with
curthread, if possible, but I still don't have a good way to resolve
choosethread() (I would dig the runqueue adding path and resolve the
problem later in the codeflow, I think).

Attilio


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