Date: Thu, 14 Apr 2005 21:46:35 GMT
Reply-To: Rusty Shackleford <rs@NATCHIE.MINE.NU>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Rusty Shackleford <rs@NATCHIE.MINE.NU>
Organization: Debian GNU/Linux site
Subject: fullstimer: user CPU time vs. system time?
I want to reduce the run time of a few big programs, so I'm using the
fullstimer system option. I get data back like:
I think I understand the real time measurement (clock-on-the-wall time),
but what is the difference between user CPU time and system CPU time?
I use a multiprocessor CPU linux server. Is the system CPU time the
sum of usage on all different CPUs?
Also, I'm reading the SUGI30 paper on randomly selecting observations,
and the author uses a term "Wall time" in his benchmarks, but I don't
know what that is either.