[slurm-users] Job runtime

[Chris Samuel]

On Sunday, 18 March 2018 5:46:50 AM AEDT Mahmood Naderan wrote:

> Excuse me but I think that is wrong.

I think we're talking at cross-purposes, I thought you were puzzled about why 
CPU time was less than the total time in a general context (not purely within 
Slurm).

> "Elapsed" is the wall clock time.

Correct.

> "UserCPU" should be "NCPUS*Elapsed".

No, that's CPUTime (as mentioned in the sacct manual page).

UserCPU is a measure of the time that the CPU spent running the program in 
user space as reported by the kernel.  Note the caveat about it on the sacct 
manual page:

https://slurm.schedmd.com/sacct.html

Also note that how you tell Slurm to gather statistics affects its accuracy.  
I've pretty much always used the cgroup method as that seems to give better 
accuracy to me (especially for memory usage).

All the best,
Chris
-- 
 Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC