Re: [patch][rfc] x86, mutex: non-atomic unlock (and a rant)

[Cyrill Gorcunov]

[Cyrill Gorcunov - Mon, Nov 02, 2009 at 07:46:26PM +0300]
| 
| The other option could be that we put two mem-write operations
| like
| 	int tmp;
| 	atomic_set(&lock->count, 1);
| 	tmp = lock->waiters;
| 	rmb();
| 	lock->waiters = tmp;
| 	if (unlikely(lock->waiters))
| 		fail_fn(lock);
| 
| Which should work faster then cpuid (and we have to be sure somehow
| that gcc doesn't suppress this redundant operations).
|

And which has nothing to do with OoO mem-read, and wouldn't
work. Sorry for noise.
 
	-- Cyrill
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/