cancel
Showing results for 
Search instead for 
Did you mean: 

CPU 100% busy

Mohamed K Ahmed
Trusted Contributor

CPU 100% busy

I have an ES40 System running V 5.1B patch kit #2, 4 processors, 4 GB memory.
As I was checking the collect command output, I found out that CPU2 is 100% busy while other CPUs are not that busy?
Is there a problem or is this something normal?

Below is the CPU part of collect
# CPU SUMMARY
# USER SYS IDLE WAIT INTR SYSC CS RUNQ AVG5 AVG30 AVG60 FORK VFORK
9 41 50 0 610 3794 3639 1 1.51 1.50 1.52 0.60 0.30
# SINGLE CPU STATISTICS
# CPU USER SYS IDLE WAIT
0 11 16 72 0
1 12 21 66 0
2 0 100 0 0
3 11 27 61 0

Mohamed
4 REPLIES
Alexey Borchev
Regular Advisor

Re: CPU 100% busy

What time slice of Your output?
"
0 11 16 72 0
1 12 21 66 0
2 0 100 0 0
3 11 27 61 0
"

IMHO, if time slice is 1-2 seconds or less - then it looks like normal.
If a system has just one active job at this partucular moment, then it run it on one of CPU's available...
Sometimes it is possible to parallelize one job on several CPU's, but in rare cases.

More then that, system schedulet tries to assign job to the same CPU - to use job's data which are still possibly in CPU cache.

If You see this picture for extended periodes of time (> 10 sec) and whith multiple jobs running on Your system - then it is strange.

P.S.
there is a command runon. Try
#man runon


The fire follows shedule...
Michael Schulte zur Sur
Honored Contributor

Re: CPU 100% busy

Hi,

I agree with Alexey. Usually a process uses up to 100% of one cpu. You also can try top or monitor to watch the machine during those times.

greetings,

Michael
Mohamed K Ahmed
Trusted Contributor

Re: CPU 100% busy

So a process can use 100% of the CPU, but does it use it continously?, I mean always the usage is 100%, I have been monitoring it all day today and it is always 100%

Is there a way I can know which process is using that particular processor?, and whay is it not multitasking and arranging the loads to other processes other than it is using that CPUs' cache
What do you think
Mohamed
Michael Schulte zur Sur
Honored Contributor

Re: CPU 100% busy

Hi,

if the cpu is 100% all the time, then something is wrong. First shot would be top to see, which processes use much cpu and then you can see, if one is among the top all the time. If you suspect one, use:
ps -eo psr,pid,command,pcpu | grep pid
or:
ps -eo psr,pid,command,pcpu | nawk '$1~/1/ {print $0}'
to see, what is running on cpu 1.

greetings,

Michael