Re: [gentoo-amd64] x86_64 optimization patches for glibc.

[Sean Johnson <gutenpress@gmail.com>]

I just reproduced your results. After emerging glibc with your overlay I get:

Memory to memory copy rate = 2265.193604 MBytes / sec. Block size = 1048576.

I was getting ~1100 before.

Nothing has broken yet, but if it does, I'll be sure to post. :)

On 7/23/05, Simon Strandman <simon.strandman@telia.com> wrote:
> Hi!
> 
> Some binary distros like Mandrake and suse patches their glibcs with
> x86_64 optimized strings and an x86_64 optimized libm to improve
> performance.
> 
> I tried extracting those patches from an mandrake SRPM and add them to
> the glibc 2.3.5 ebuild. The x86_64 optimized strings patch built and
> worked perfectly and gave a large speedup as you can see below. But I
> couldn't get glibc to build with the libm patch because of unresolved
> symbols (and I'm no programmer so I have no idea how to fix that).
> 
> I found a small C program on a suse mailing-list to measure glibc memory
> copy performance:
> http://lists.suse.com/archive/suse-amd64/2005-Mar/0220.html
> 
> With the glibc 2.3.5 currently in gentoo I get:
> isidor ~ # ./memcpy 2200 1000 1048576
> Memory to memory copy rate = 1291.600098 MBytes / sec. Block size = 1048576.
> 
> But with glibc 2.3.5 + amd64 optimized strings I get:
> isidor ~ # ./memcpy 2200 1000 1048576
> Memory to memory copy rate = 2389.321777 MBytes / sec. Block size = 1048576.
> 
> That's an improvement of over 1000mb/s! Suse 9.3 also gives about
> 2300mb/s out of the box.
> 
> How about adding these patches to gentoo? Perhaps in glibc 2.3.5-r1
> before it leaves package.mask? I'll create a bugreport about it if you
> agree!
> 
> This .tar.bz2 contains the glibc directory from my overlay with the
> mandrake patches included in files/mdk, but the libm patches are
> commented out in the ebuild.
> http://snigel.no-ip.com/~nxsty/linux/glibc.tar.bz2
> 
> --
> Simon Strandman <simon.strandman@telia.com>
> 
> --
> gentoo-amd64@gentoo.org mailing list
> 
>

-- 
gentoo-amd64@gentoo.org mailing list