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-**************************************************************************
-* The following are notes for all scripts that measure elapsed time.
-*
-* $Id: ALLelapsed_notes.txt 44 2007-09-17 07:47:20Z brendan $
-*
-* COPYRIGHT: Copyright (c) 2007 Brendan Gregg.
-**************************************************************************
-
-
-* What is "elapsed" time?
-
-Elapsed time is the absolute time from one point to another. This time
-includes everything that happened between these points, including
-off-CPU time due to other system events such as I/O, scheduling,
-interrupts, etc. It also includes the small overheads of DTrace itself.
-
-Elapsed times are useful for identifying where latencies are, since
-regardless of their nature (CPU, I/O, ...), they will be visible in
-elapsed time.
-
-Since elapsed times don't filter out anything, they are suseptible to
-"noise" - random system events that are unrelated to the analysis target.
-For that reason, it may be best to take several measurements of elapsed
-time and take the average (or run your workload several times and let
-DTrace take the average).
-
-See Notes/ALLoncpu_notes.txt for a description of a different time
-measurement, "on-CPU" time.
-
-
-* How is "elapsed" time measured?
-
-In DTrace, the following template provides elapsed time as "this->elapsed",
-
- <start-probe>
- {
- self->start = timestamp;
- }
-
- <end-probe>
- {
- this->elapsed = timestamp - self->start;
- self->start = 0;
- ...
- }
-