Re: [RFC] x86-64: Use SSE for copy_page and clear_page

[Benjamin LaHaise]

On Tue, May 31, 2005 at 11:23:58AM +0200, Andi Kleen wrote:
> fork is only a corner case. The main case is a process allocating
> memory using brk/mmap and then using it.

At least for kernel compiles, using non-temporal stores is a slight 
win (a 2-5s improvement on 4m30s).  Granted, there seems to be a 
lot of variation in kernel compile times.

A bit more experimentation shows that non-temporal stores plus a 
prefetch of the resulting data is still better than the existing 
routines and only slightly slower than the pure non-temporal version.  
That said, it seems to result in kernel compiles that are on the high 
side of the variations I normally see (4m40s, 4m38s) compared to the 
~4m30s for an unpatched kernel and ~4m25s-4m30s for the non-temporal 
store version.

		-ben
-- 
"Time is what keeps everything from happening all at once." -- John Wheeler
-
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/