sem_trywait changes broke sparc

[Torvald Riegel]

On Mon, 2015-02-02 at 11:47 -0800, David Miller wrote:
> From: Torvald Riegel <triegel@redhat.com>
> Date: Mon, 02 Feb 2015 10:29:14 +0100
> 
> > Thanks Dave.  I scanned through the patches you committed and they
> > looked good to me.
>  
> BTW, the original 32-bit sparc semaphore implementation did something
> similar, by using an in-semaphore spinlock to implement the
> synchronization.
> 
> They didn't use the spinlock array, just like my adaptation of your
> code does not.

Right.  And that is required to make process-shared semaphore work
correctly because the spinlock array isn't shared.