Re: [patch] Cache align futex hash buckets

[Christoph Lameter]

On Tue, 21 Feb 2006, Nick Piggin wrote:

> Ravikiran G Thirumalai wrote:
> > Following change places each element of the futex_queues hashtable on a
> > different cacheline.  Spinlocks of adjacent hash buckets lie on the same
> > cacheline otherwise.
> > 
> 
> It does not make sense to add swaths of unused memory into a hashtable for
> this purpose, does it?

It does if you essentially have a 4k cacheline (because you are doing NUMA 
in software with multiple PCs....) and transferring control of that 
cacheline is comparatively expensive.
-
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/