Re: test6-lowlatency-D1 results: 50msec + hangs ....

[Philipp Rumpf]

On Sat, Aug 05, 2000 at 09:16:55PM +0200, Benno Senoner wrote:
> Hi,
> 
> here the results of Ingo's  lowlatency-test6-pre2-D1 patch:
> 
> to mention that I had to remove these two lines in
> /drivers/char/pc_keyb.c:
> 
>       if (!spin_is_locked(&kbd_controller_lock))
>               BUG();

That's bogus on UP (spin_is_locked always returns 0).

I think it would be reasonably nice to have something like

spin_lock_held(spinlock_t *lock);

that returns 1 for UP and spin_is_locked(lock) for SMP - basically 

foo() 
{
	if (!spin_lock_held(&foo_lock))
		BUG();

	...
}

looks to me like it'll avoid errors more effectively than

/* Call with foo_lock held */
foo()
{
	...
}

	Philipp Rumpf