Cpu Management Or How To Disable One Core

Is it possible to somehow disable one core for one program? Or disable the CPU management? I'm trying to run an old program that wasn't made for two cores and it's speed varies making it hard to use... I've tried disabling KPowerSave, powerd, powersave, acpid, booting with acpi=off, but no effect... When the CPU management is on, the program runs on normal speed for like 10 seconds, then 5 seconds on fast speed, then again 10 seconds on normal etc. When I disable KPowerSave or set it to performance mode, the program runs 2 seconds normally and 2 seconds fast and repeats. I've heard about a CPU governor in /sys/devices/system/cpu/cpuX/cpufreq/scaling_governor, what does it do and how to enable it?
I'm using OpenSUSE 10.2, KDE 3.5.

In Windows XP, the problem is simply fixed by disabling one core for the program in Task Manager.

I've heard about a CPU governor in /sys/devices/system/cpu/cpuX/cpufreq/scaling_governor, what does it do and how to enable it?
I'm using OpenSUSE 10.2, KDE 3.5.
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That's precisely what you're doing when enabling "Performance" in KPowersave, you're setting the scaling_governor to the performance setting, which disables cpu frequency scaling. But that only impacts clock speed, there's no configurable way to alter CPU switching. Though is sounds like your application is not a multi-threaded one, so it shouldn't be impacted by SMP anyways.

In Windows XP, the problem is simply fixed by disabling one core for the program in Task Manager.
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Again, per my post above, I'm really not sure why that would make a difference. AFAIK, the OS Kernel balances processes between cpus, but it shouldn't have an impact on the performance of a single process on one kernel, unless another process is robbing it of cycles. If that was the case, disabling the cpu accessibility for the app wouldn't make a difference, since the culprit would have to be addressed directly.

If you want to experiment, you can boot into uni-processor mode by using the "nosmp" kernel option at boot time. When grub comes up and your default kernel is pre-selected, just type in "nosmp" and hit enter to boot. That will disable SMP, reducing you to a single core, and you can evalutate any performance impact that way.

Hope this helps?

Cheers,
KV

Found a way to disable one myself. But that didn't help... It's just running too fast at times, and I have no idea why. Actually, I've noticed the same thing on several programs - Super Tux, Unreal Tournament through Wine etc. That might be an issue with rendering - some renders work normally, like Software rendering in Unreal Tournament. I'll experiment a little with Wine and those boot options then, if it doesn't work, then I'll just keep using Software Rendering and wait for a newer Wine...