How to change the kernel latency ?.

[blowthebullet]

Hello,

I don't no how to change the kernel lantency to 1000 hz. Can someone help me pls.

I use Fendora 5 Linux


blow.

[hexitnow]

This isnt a one step process. I would look it up on the fedora website because the whole process can take a few hours as I run a 1000HZ kernel with ubuntu. Actually i would google 1000 HZ and that should yield somethin. But to start you need alot of different liraries before u can compile the code.
You need to be root for this.
apt-get install build-essential bin86 kernel-package libqt3-headers libqt3-mt-dev
That will install and download the necessary libraries for you. After u do that go to kernel.org and download the kernel vers u need. This should help get u started.

[fqdn]

this is what i used to update my kernel (instructions are for centos which is based on rh, the same with fedora) disclaimer: if you blow up your server don't blame me.

in the section below where i marked with "here here here" will be choices for kernel frequency just choose 1000hz instead of the default and hit enter for the rest.

Quote:cd /usr/src/
http://www.kernel.org/pub/linux/kern....6.16.1.tar.gz
tar -zxf linux-2.6.16.1.tar.gz
cd linux-2.6.16.1

cp /boot/config-2.6.9-22.0.2.EL .config
make clean (only necessary if you compile more than once)
make oldconfig

HERE HERE HERE
keep hitting enter and take the defaults until you get to the CPU type. Select your CPU. Also in the SMP section select SMP if you have multiple CPUs. Oh, and select "(No Forced Preemption (server))" under that section. Everything else, just hit enter to take the defaults.

(this is the "quick and dirty" method. You can also run "make menuconfig" instead, go to the bottom of the menu, load your old config file, and then select everything in a menu individually if you wish. For most systems, the "make oldconfig" method works fine.)


Then to compile and install:

make bzImage
make modules
make modules_install
make install


Then to configure your boot loader in case of disaster:

nano /boot/grub/grub.conf

Code:

default=1 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title CentOS (2.6.16.1) root (hd0,0) kernel /vmlinuz-2.6.16.1 ro root=/dev/VolGroup00/LogVol00 initrd /initrd-2.6.16.1.img title CentOS (2.6.9-22.0.2.EL) root (hd0,0) kernel /vmlinuz-2.6.9-22.0.2.EL ro root=/dev/VolGroup00/LogVol00 initrd /initrd-2.6.9-22.0.2.EL.img title CentOS_ServerCD (2.6.9-22.EL) root (hd0,0) kernel /vmlinuz-2.6.9-22.EL ro root=/dev/VolGroup00/LogVol00 initrd /initrd-2.6.9-22.EL.img


..make sure it looks something like this with default=1 and the new kernel (2.6.16.1) on top. (Grub starts at 0, so "default=1" is still your old kernel. You change this later if it works out ok)




..then configure grub to boot to the new kernel one time. This way if it panicks or you can't get to the machine because the network service blows up, you can have the data center do a reboot and it will default back to the last kernel. If it does boot ok and everything looks good, edit grub.conf again and change it to "default=0" and it will boot the new kernel by default after that.

grub
savedefault --default=0 --once
quit

Reboot and see what happens. If it hangs, reboot again and you'll be back to your previous kernel.
Good luck.

[KevinIN72]

now what does doing that change, better performence??

[hexitnow]

Yeah, it gives a boost in FPS, I run my linux server which caps out at like 500 fps. Without the timer hz change i would be running about 333 fps.

[KevinIN72]

Yeah but will the higher FPS make a diffrents to the player, or is it just effected serverside.

[hexitnow]

Well if your server can only run 60 FPS no one in but when 4 people are in there its gonna be down to 22 FPS. It's gonna lag hardcore. Changing the kernel boosts the server FPS, resulting in better performance for clients too.

[fqdn]

oh note that 2.6.16.1 is not the most current kernel, in fact it's pretty old. just go to kernel.org and you'll see what the most current one is.

edit: instead of going with the most current, look for the one that is the most stable. a lot of the smaller revisions are to fix certain problems.