CPU schedule policy

[tempest92]

hi,

i have asked a question by someone at my site -

does aix have a command to change the cpu scheduling policy of a process. apparently (??), in other unix's (i have been told) you can make a process "real time" which means it will not be placed back at the end of the queue once it's timeslice on the cpu is exhausted, it just stays on the cpu until it is complete, i assume with a static priority.

this is not for a prod environment, purely just to understand if this is available in aix.

thanks in advance !!

 

[mag007]

Maybe 'nice', or 'renice' will be helpful.

 

[spamly]

Sounds like you're working with a mainframer.

You can make a process real time. It's a good way to lock up your system. Every time I've asked a vendor how to do it they've just said, "Don't."

If you are going to play around with your processes, I'd also suggest nice and renice.

Good luck.

 

[letis]

hello,

it's a bit more complex in AIX, ie the priority itself and the fact that your thread has full time slices are somethings different.

For a developper, you need first to use the setpri() system call to set the priority ou your thread, and the thread_setsched()to choose a scheduling policy (for example, Oracle runs with a scheduling policy called "fixed priority").

Scheduling policy are described in AIX doc, use the keyword "scheduling threads" from the doc portal here :

http://publib.boulder.ibm.com/infoc...c/com.ibm.aix.doc/doc/base/aixinformation.htm

From an admin point of view, you can use the nice and renice command to change the priority of a process, but keep in min that by default, priorities vary with time.

regards,

 

[tempest92]

thanks everyone !!