On 27.09.2010 21:44, Ramkumar Ramachandra wrote:
Hi Stefan,
Could you tell me which tools you use to profile the various
applications in trunk? I'm looking to profile svnrdump to fix some
perf issues, but OProfile doesn't seem to work for me.
Thanks.
-- Ram
Hi Ram,
Under Linux, I'm using Valgrind / Callgrind and visualize in KCachegrind.
That gives me a good idea of what code gets executed too often, how
often a jump (loop or condition) has been taken etc. It will not show the
non-user and non-CPU runtime, e.g. wait for disk I/O. And it will slow the
execution be a factor of 100 (YMMV).
Under Windows, I'm using the VisualStudio sampling profiler. The
measurements
are pretty accurate and the overhead is low. It does not tell me, how often
a certain code path has been executed. Due to the low overhead, it is
well-suited for long running (>1 min) operations.
Also, I find a simple "time <command>" very useful to get a first impression
whether my code is bound by user-runtime, I/O wait or system runtime.
To collect data on I/O activity, compression rates and other not readily
available information, I use simple static counters and printf() their
values
at the end of each client call, for instance.
Hope that helps.
-- Stefan^2.
