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 <[EMAIL PROTECTED]>
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