Timing Anomalies of Source Profiler |
Q103785
Profiling applications with Microsoft Source Profiler may produce inconsistent and incorrect timing information in some cases. The information below describes such situations.
Profiling applications on systems that have built-in memory caches or
disk caches may produce erratic time reports. The number of
instructions from the application's code and the profiler's code that
gets loaded in the cache cannot be controlled, and this causes the
timing inconsistencies.
Profiling applications under Windows versions 3.0 and 3.1, when other
tasks are running, may produce incorrect timing information on the
applications being profiled. This problem is caused by the time spent
on other tasks being attributed to the application being profiled.
The profiler must compensate for Windows protected-mode and
device-driver overhead when recording timing information. This can
cause timing by line and timing of short functions or procedures to be
inaccurate. These inaccuracies can accumulate and cause the total
program execution time shown by the profiler to be greater than the
actual time taken by the program.
In general, Windows standard mode gives better timing results than 386
enhanced mode.
In the case of FORTRAN programs compiled using Microsoft FORTRAN
versions 5.0 and 5.1 with the /4Yb compiler option (or $DEBUG
metacommand), additional code is generated for expanded error
handling, and this may result in an increase in the Profiler timing
information.
a=func(4.0)
print*, a
end
function func(s)
func=sqrt(s)
return
end
Additional query words: kbProfiler s 5.00 5.10 kbDSupport kbdss
Keywords : kbcode kb16bitonly TlsMisc
Issue type :
Technology :
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Last Reviewed: December 22, 1999 © 2001 Microsoft Corporation. All rights reserved. Terms of Use. |