Increase CPU usage and keep it at a certain level using C code

Question

I am writing C code (on Linux) that must consume a certain amount of CPU when it starts. I am doing an experiment in which I run certain actions when a certain threshold of the CPU is reached. So, once Disposal reaches a certain threshold, I need to keep it in this state, for example, 30 seconds before the completion of my experiments. I control the CPU usage with the top command.

So my questions are 1. How do I increase CPU utilization to a given value (in a deterministic way, if possible)? 2. As soon as I get to the threshold, is there a way to keep it at this level for a predetermined time?

An example of the output of the upper command (the 9th column is the processor used by the "top" process) 19304 abcde 16 0 5448 1212 808 R 0.2 0.0 0: 00.06 top

As above, I will look at the line above that shows the use of my binary.

Any help would be greatly appreciated. Also, let me know if you need more information.

Thanks!

Edit: The following lines of code allowed me to pretty well control the CPU usage. In the following case, I have 2 options: keep it above 50% and keep it below 50%. After some trial and error, I settled these usleep values.

endwait = clock() + ( seconds * CLOCKS_PER_SEC ); while( clock() < endwait ) {} if (cpu_utilization > 50) usleep(250000); else usleep(700000); 

Hope this helps!

Answer 1

cpuburn , as you know, makes the processor load so high that it raises its temperature to the maximum level. It seems there is no longer an official site on it, but you can access the source code with a Debian or googlecode package . It is implemented in asm, so you have to make some glue to interact with it in C.

Answer 2

Something like this should have constant CPU usage, in my opinion: md5sum </ dev / urandom