Re: FUSYN and RT

[john cooper]

Sven Dietrich wrote:
> > > 	/** A fuqueue, a prioritized wait queue usable from
> >
> > kernel space. */
> >
> > > 	struct fuqueue {
> > > 	        spinlock_t lock;        
> > > 	        struct plist wlist;
> > > 	        struct fuqueue_ops *ops;
> > > 	};
> >
> > Would the above spinlock_t be a raw_spinlock_t? This goes
> > back to my first question. I'm not sure how familiar you are 
> > with Ingo's work, but he has turned all spinlocks into 
> > mutexes, and when you really need an original spinlock, you 
> > declare it with raw_spinlock_t.  
>
>
> 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.

-john


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