Hi Todd...

Heywood, Todd wrote:
> I'm just starting to run mpiBLAST jobs, and I'm noticing, using vmstat, that 
> the vast majority of CPU time is system time, not user time. Is this normal?
>
> Thanks.
>
> Todd Heywood
>   

Whether that's normal depends on which mpiblast process you were 
monitoring and a few other details.  mpiblast processes have three 
roles: writer, scheduler, and worker.  For a perfectly load-balanced 
search, the workers should probably be more user-time than system time.  
The writer can have substantial system time because it does lots of disk 
I/O and communication, and what little CPU time the scheduler uses will 
probably be system time for communication overhead.  Depending on the 
search type and database, i.e. blastn, blastp, tblastx etc, the relative 
amounts of system time to user time for workers can change 
substantially.  blastn can be extremely I/O intensive, while tblastx 
tends to be compute intensive.

-Aaron

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