Re: interrupt checks for spinlocks

[William Lee Irwin III <wli@holomorphy.com>]

On Sun, 2002-11-03 at 20:42, William Lee Irwin III wrote:
>> I'll go figure out why before posting a follow-up. This is not doing
>> what I wanted it to because the only one I originally wanted was (1),
>> having to do with interrupt-time recursion on rwlocks and writer
>> starvation caused by it.

On Sun, Nov 03, 2002 at 10:01:24PM -0500, Robert Love wrote:
> You can do #1, but you need to figure out if your interrupt is the only
> interrupt using the lock or not (possibly hard).
> In other words, a lock unique to your interrupt handler does not need to
> disable interrupts (since only that handler can grab the lock and it is
> disabled).
> If other handlers can grab the lock, interrupts need to be disabled.
> So a test of irqs_disabled() would show a false-positive in the first
> case.  No easy way to tell..
> 	Robert Love

Sounds like I rip out that check and ignore the fact it's useless for
its original intended purpose. No matter, it'll turn up something.

Incoming.

Bill