svn commit: r313006 - in head: sys/conf sys/libkern sys/libkern/x86 sys/sys tests/sys/kern

[Bruce Evans]

On Wed, 1 Mar 2017, Conrad Meyer wrote:

> On my laptop (Intel(R) Core(TM) i5-3320M CPU — Ivy Bridge) I still see
> a little worse performance with this patch.  Please excuse the ugly
> graphs, I don't have a better graphing tool set up at this time:
>
> https://people.freebsd.org/~cem/crc32/sse42_bde.png
> https://people.freebsd.org/~cem/crc32/sse42_bde_log.png

Try doubling the loop sizes.  There shouldn't be any significant difference
above size 3*LONG unless LONG is too small.  Apparently it is too small for
older CPUs.

I now have a Sandybridge i5-2xxx laptop to test on, but don't have it set
up for much yet.

Bruce