kernel hz above 1000 hz on a 64 bit debian OS

[Topspeed]

hi
i would like to raise kernel hz above 1000, e.g. 1500 or 2000hz. it there a way to do that or is it impossible?
in kernel-configuration i can choose between 100, 250 and 1000 hz, but no higher values.

thank you very much for answering!

[thamarok]

It's impossible, because there is no setting to make it over 1000Hz. Why would you want a higher value anyway?
As far as I know, there is no program requiring more than 1000Hz.

Perhaps you need realtime preemption? But that's another thing.

[Topspeed]

Hi thamarok

i'd like to boost my CS:Source dedicated gameserver. With kernel hz 1000 and patches from Con Kolivas, empty big kernel lock and preemption model (low latency) and some other tweaks, i only get 333 FPS on 64 bit os. On 32 bit debian it's no problem to get 500 FPS.
i've read somewhere, that the 64 bit version is better than the 32 one for cs:source...
on some other linux distributions there is an advantage in setting user_hz 1000, but on debian i could not improve performance with it.

any other ideas to get higher fps on debian 64 bit?

thanks a lot!

[thamarok]

Ok, that explains everything
I see you even patched the kernel with the ck patches... if you even did that I don't know how to boost the performance of your server..

I'm running 2 Game Servers: One is for my private MMORPG and the other is for Ragnarok Online; I'm using a 32-bit kernel and I have and FPS of 700 and sometimes when the system is not on load, it has 800 FPS.

[Topspeed]

i changed all 1000 values to 1500 in kernel/Kconfig.hz, did make menuconfig and compiled the kernel with success!
now my cs:source dedicated server runs at 500 FPS on Debian 4.0 RC1 64 bit.

[thamarok]

i changed all 1000 values to 1500 in kernel/Kconfig.hz, did make menuconfig and compiled the kernel with success!
now my cs:source dedicated server runs at 500 FPS on Debian 4.0 RC1 64 bit.

Cool!
I might try with 2000Hz then

[Topspeed]

i could not compile with 2000hz....
good luck!

btw: my cs:source dedi needs now ~25% more cpu-power than with the old 1000hz kernel. (e.g. if the max load earlier was 40% of CPU, now its 50%)

[thamarok]

i could not compile with 2000hz....
good luck!

btw: my cs:source dedi needs now ~25% more cpu-power than with the old 1000hz kernel. (e.g. if the max load earlier was 40% of CPU, now its 50%)

Which kernel source did you try to compile?
I'm trying to compile the new 2.6.20-rc3

[Topspeed]

i used 2.6.19 with cks2, empty big kernel lock, preemption (low latency)

could you compile with 2000 hz and 2.6.20 kernel?

[thamarok]

No, it failed too.
I might do a dirty hack to the kernel source and allow it to have 2000Hz.

EDIT: But it might work with 1999Hz; I mean if that succeeded, the differencly would be only 1Hz