Re: [patch 1/4] x86: FIFO ticket spinlocks

[Nick Piggin]

On Fri, Nov 02, 2007 at 08:56:46PM -0400, Chuck Ebbert wrote:
> On 11/02/2007 07:01 PM, Nick Piggin wrote:
> > 
> > In the contended multi-threaded tight loop, the xchg lock is slower than inc
> > lock but still beats the fair xadd lock, but that's only because it is
> > just as unfair if not more so on this hardware (runtime difference of up to
> > about 10%)
> > 
> 
> I meant xchg for unlock, not lock.

That is for unlock. 2x the number of atomic operations ~= 2x the cost.

-
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/