[linuxperf] system time on SMP

["Jochen Frey" <jochen_frey@yahoo.com>]

Hi there, I am new to this list, so please bear with me. I searched the
list, but I might have missed stuff.

The symptom: I am running performance test on a multi processor machine, and
when I put it under load, the processors spend 50% of their time in user
processes and 50% of the time in system processes (sometimes it's 60:40).
This is not what I'd expect, I'd expect close to 85% of the time in user
processes (realistic?).

The question: Any pointers as to what the system might be doing? I used sar,
and it's not swapping, there's plenty of memory (2GB) (but maybe not used),
and network is not an issue.

The architecture:
* SW: LAMP (red hat 7.1, apache, mySQL, PHP) most of those in the latest
versions.
* HW: Dell 8450 (8 processors, 2GB Memory)

The load type: Lots of brief stateless requests (short translations),
requiring many simple 'selects' from mySQL (one table only, relatively
simple lookups using indexes).

Any pointers / suggestions / etc?

Thanks so much!
Jo

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