Re: DRM lock ordering fix series

[Peter Zijlstra]

On Sat, 2009-03-28 at 01:58 +0100, Peter Zijlstra wrote:

> > OK.  I'm not too excited here -- 10% of 2% of the CPU time doesn't get
> > me to the 10% loss that the slow path added up to.  Most of the cost is
> > in k{un,}map_atomic of the returned pages.  
> 
> Also note that doing large gup() with gup_fast() will be undesirable due
> to it disabling IRQs. So iterating say several MB worth of pages will
> hurt like crazy. Currently all gup_fast() users do a single page lookup.

Also, what's this weird facination with 32bit, can you even buy a 32bit
only cpu these days?

--
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/