Gentoo Archives: gentoo-amd64

From: Simon Strandman <simon.strandman@×××××.com>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] x86_64 optimization patches for glibc.
Date: Sat, 23 Jul 2005 14:49:32
Message-Id: 42E258A7.5080501@telia.com
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@×××××.com>

-- 
gentoo-amd64@g.o mailing list

Replies

Subject Author
Re: [gentoo-amd64] x86_64 optimization patches for glibc. Allan Wang <allanvv@×××××.com>
Re: [gentoo-amd64] x86_64 optimization patches for glibc. Matt Randolph <mattr@×××××.com>
Re: [gentoo-amd64] x86_64 optimization patches for glibc. Sean Johnson <gutenpress@×××××.com>
Re: [gentoo-amd64] x86_64 optimization patches for glibc. ardour <ardour@×××××××.be>
Re: [gentoo-amd64] x86_64 optimization patches for glibc. Jeremy Huddleston <eradicator@g.o>