Re: FUSYN and RT

[john cooper <john.cooper@timesys.com>]

Steven Rostedt wrote:
> On Sat, 2005-04-16 at 09:05 -0400, john cooper wrote:
> 
>>Sven Dietrich wrote:
> 
> [...]
> 
>>>This one probably should be a raw_spinlock. 
>>>This lock is only held to protect access to the queues.
>>>Since the queues are already priority ordered, there is
>>>little benefit to ordering -the order of insertion-
>>>in case of contention on a queue, compared with the complexity.
>>
>>The choice of lock type should derive from both the calling
>>context and the length of time the lock is expected to be held.
>>
> 
> 
> In this case, I don't think time matters for choice of lock. Time
> matters to keep it short since it does need the raw_spin_lock.  This
> lock is part of the whole locking scheme, and would be similar to not
> using raw_spin_locks in the implementation of rt_mutex.  Well, not
> exactly the same, but if we want the fusyn code to use the same code as
> rt_mutex for PI, then it will need to be a raw_spin_lock.

Ok, I was missing the context -- it does need to be a raw lock.
Is the scope of this lock limited to manipulating the list or
is it held to serialize other operations?

-john


-- 
john.cooper@timesys.com