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HOWTO_INTEL_XEON_WITH_EM64T_Optimizations


This article is part of the HOWTO series.
Installation Kernel & Hardware Networks Portage Software System X Server Gaming Non-x86 Emulators Misc

Contents

Installing

Running Gentoo on machines like this is practically like running it as an AMD64 since they both use simliar architecture. If you want to read more about EM64T and what it is, please check out Intel's page for more information. For most of the installation, just refer to the Gentoo AMD64 installation handbook and don't forget to read all the important information on the Gentoo AMD64 site! (plz. pay attention you have to start from a AMD64 stage3 tarball, if you use a i686 you CAN'T swith to the new architecture x86_64, because the gcc toolchain refuses the march change) Here are some of the things I encountered to stabilize a server:

My usual rule of thumb is to follow the K.I.S.S. (Keep It Simple Stupid) approach when dealing with servers. One thing to note is that the technical term for the architecture these cpus have is called nocona.

Recognizing x86_64 Enabled CPU (Useful for Xeon(tm) Processors)

cat /proc/cpuinfo

Check for the 'lm' flag. If you read somewhere that Xeon nocona cpu has to support SSE3, this is true but it's named PNI in cpuinfo.

make.conf settings

File: make.conf
CFLAGS="-O2 -march=nocona -pipe"
CHOST="x86_64-pc-linux-gnu"
CXXFLAGS="${CFLAGS}"
USE="nptl multilib apache2" # This was used for a server running apache

Kernel Options

Linux Kernel Configuration: Setting the correct Processor Family
( ) AMD-Opteron/Athlon64
(X) Intel EM64T
( ) Generic-x86-64

This will enable CONFIG_MPSC which states:

Optimize for Intel IA32 with 64bit extension CPUs
(Prescott/Nocona/Potomac)

For the rest of the kernel, just make sure you use the dmesg output and lspci output to get all the drivers you need. Its best to leave out any support for hardware you know you won't use (i.e. usb, framebuffer, etc).

For reference, I used the gentoo-dev-sources kernel instead of the vanilla because there are a few patches that have been added that seem to work better. The default kernel on Gentoo for the AMD64 is the 2.6.x series. If you need to use a 2.4.x kernel, be aware that support has practically been abandoned because these machines work so much better using 2.6.x.

EM64T Dual Core

TIP: On some motherboards, such as the Asus P5VD1-X, if you disable hyperthreading in the BIOS, your SMP kernel will not recognize the second core.

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Last modified: Fri, 29 Aug 2008 04:45:00 +0000 Hits: 29,815