Changing Quantum in Linux

[OgreCoder]

I have an assignment where I have to add a system call to the 2.6.3 kernel to both find out what the quatum of the processor is and change it. We can change what they call both MAX_TIMESLICE and MIN_TIMESLICE. I know how to add a system function to the kernel, but does anyone know what variables I am trying to set and how to obtain them. Thank you very much.

[Wizard]

My multithreaded terminology is a little shody, so someone correct me, but isn't the quanta the timeslice between thread flips? Wouldn't that make MAX_TIMESLICE and MIN_TIMESLICE the max and min quantum respectively? I don't understand the problem.

[OgreCoder]

That is exactly the problem I am working on. MIN and MAX_TIMESLICE are the time between context switches. I need to know how to query these values and change them. They aren't environment variables, so setenv() and getenv() won't work. If any body knows anything, it would be helpful.

[Wizard]

did you try

Code: Select all

MIN_TIMESLICE = 50000;

or something equally simple? If you have, then I'm out of ideas. I've never worked with the Linux kernel, so I'm guessing.

[sAvAgE]

to access the calls to the kernel in your program for example you can use this

you will need to includethese headers in your code

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#include <unistd.h>
#include <stdio.h>
#include <pthread.h>
#include <sys/stat.h>  //kernel call
#include <sys/types.h> //kernel call
#include <string.h>


also you can read up on the POSIX library Here

hope this helps