Re: FUSYN and RT

From: Steven Rostedt
Date: Sat Apr 16 2005 - 09:25:07 EST


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.

-- Steve


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