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Diffstat (limited to 'cddl/contrib/dtracetoolkit/Notes/ALLelapsed_notes.txt')
-rw-r--r-- | cddl/contrib/dtracetoolkit/Notes/ALLelapsed_notes.txt | 46 |
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diff --git a/cddl/contrib/dtracetoolkit/Notes/ALLelapsed_notes.txt b/cddl/contrib/dtracetoolkit/Notes/ALLelapsed_notes.txt deleted file mode 100644 index 9e8f314feae2..000000000000 --- a/cddl/contrib/dtracetoolkit/Notes/ALLelapsed_notes.txt +++ /dev/null @@ -1,46 +0,0 @@ -************************************************************************** -* 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; - ... - } - |