Re: optimizations [for non-debugging] amd64 kernels
Blair Sadewitz <blair.sadewitz <at> gmail.com>
2007-09-11 11:09:31 GMT
On 9/11/07, Hubert Feyrer <hubert <at> feyrer.de> wrote:
> On Tue, 11 Sep 2007, Hubert Feyrer wrote:
> > Now - speed, time, diskspace, ...?
> Doh, s/Now/How/
Oh, speed/time. It's a lot faster. My GENERIC.MP kernel was built
with -march=nocona, so I know it's not that alone. When I get a
chance, I'll time some compile jobs.
is an enhancement for x86_64 memcpy/bzero/bcopy functions in
common/libc. This is authored by fuyuki <at> hadaly.org and is a slight
modification of the latest version (<see
http://www.hadaly.org/fuyuki>) of what was originally posted in a PR
back around Jan/Feb.
I changed the size given to the cmpq instruction right below the
remark on non-temporal hints to match the cache size of my CPU
(2MB)/4. I'm not sure what it should be by default. Also, I added
the #ifndef _KERNEL, as AFAIK the kernel doesn't copy such long
strings. I've been using this for ~6 mos now with no ill effects
insofar as I can tell.
I shared this with christos <at> about 6-8 weeks ago,
and he said that it looked good to him. I posted it to the list also,
but there was no response.