nice does not seem to work in prioritizing large processes??
 

Hi everyone. I have been playing around with the nice process prioritizing utility and it does not seem to work as well as I have generally been led to believe it should.

Can someone check my understanding and give me some input on the role of nice?

Specifically I am trying to compile KDE ...AND... OpenOffice.org in the background on my Gentoo (linux) system having 512 MB RAM. Running on a Pentium III 450 MHz.

Now normally I can nice something like compile KDE and OpenOffice in the background with no problem and still run Konqueror, KDE, KMail and whatever else I want with no problems. In the sense that everything appears to work just as fast as if I was not compiling the large background projects.

But not when it comes to using OpenOffice while nicing these compiles in the background. OpenOffice (the currrent compiled version that I am using while the compile of the newer version and KDE is occurring in the background) slows to an absolute crawl.

Looking at the System Load graphics through KDE System Guard the nice processes are taking up a huge chunk of system resources. All the time. No matter what nice I put them at. While the opening of OpenOffice seems to affect the CPU Load and Physical Memory hardly at all.

It's as if nice adheres to my nice prioritizing for everything else but OpenOffice.

I have used a "nice -n 15" for an emerge (installation and compilation) of OpenOffice and a "nice -n 16" for an emerge of KDE while opening the current version of OpenOffice so as to work in it while compiling in the background. Since these nice values should cause the compilation to be given resources as a low priority I don't understand why OpenOffice (the working program) is affected so adversily.

Is nice, nice to use unless one is activating processes like large compiles that take up huge amounts of system resources in and of themselves? Is it of any real use when working on a Pentium III with 512 MB RAM? Is it doing anything at all in my case?

The ONLY noticeable thing that happens when I open OpenOffice (the working copy) is that there are spikes in the proportion of CPU Load being taken up by applications. But when that happens there is not a corresponding decrease in that taken up by the niced background processes. As I would expect given that I niced those processes to be a low priority.

Why does nice not seem to release resources to my OpenOffice application when those resources seem to be needed?

Any insight or input would be much appreciated.

Thanks.

Carlos

your problem is that compiling applications makes a LOT of
harddisk access. Nice is nice to priorize the CPU. It can't avoid
high priority tasks waiting for hard disk access.