performance questions

Issues related to hardware problems
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mjenn200
Posts: 7
Joined: 2013/07/20 15:20:47

performance questions

Post by mjenn200 » 2013/08/02 15:49:10

Hi,
I am doing some investigation into a centos server that seems to be running slowly. I believe the server has two Xeon E5405 processors.


When the servers job is running (a bespoke app), running top reveals that %CPU is always above 90%.


This is the output of mpstat -P ALL

16:45:00 CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
16:45:00 all 0.34 0.50 0.25 0.37 0.00 0.01 0.00 98.53 1036.05
16:45:00 0 0.16 0.36 0.22 0.09 0.00 0.00 0.00 99.17 1000.15
16:45:00 1 0.19 0.39 0.22 0.07 0.00 0.00 0.00 99.12 0.01
16:45:00 2 0.18 0.46 0.21 1.12 0.00 0.01 0.00 98.03 9.32
16:45:00 3 1.39 0.96 0.34 1.03 0.00 0.02 0.00 96.26 19.48
16:45:00 4 0.29 0.43 0.25 0.25 0.00 0.00 0.00 98.77 0.48
16:45:00 5 0.22 0.45 0.21 0.25 0.00 0.00 0.00 98.85 1.66
16:45:00 6 0.10 0.43 0.23 0.10 0.00 0.00 0.00 99.14 3.59
16:45:00 7 0.21 0.51 0.27 0.07 0.00 0.00 0.00 98.93 1.36


I don't quite understand why all cores are showing as 99% idle, when top shows processor usage at over 90%, why is this?

Also, I am concerned about the high number of interrupts / second on CPU 0. How can I track this down? Is it likely to be a problem?

I have run: sar -I XALL 2 10, but this does not really give me any clues as to what the innterupt number is.

Also, it does look like I have irqbalance running.


All advice gratefully received!

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