On 12/8/05, Steve Harris <S.W.Harris@email-addr-hidden> wrote:
> On Wed, Dec 07, 2005 at 07:13:30 -0800, Noah Roberts wrote:
> > Could the RT patch be interfearing with my ability to run gprof?
> > AFAICT I did everything right to use it, used the -pg on compile for
> > instance, but my profiles have no time at all in them:
>
> IIRC gprof works by sampling program activity at some interval. My
> experience with realtime code is that it doesnt spend long enough doing
> anything in particular to get meaningful results.
Well, _my_ code is not realtime. Basically all I am doing is a
benchmark of std::string vs. char*.
>
> I think you will get better results by using cachegrind et al and running
> in freewheel mode so it doesn't get kicked off.
Hmmm...never heard of those things. Will have to google them later.
>
> Failing that you can write your own profiling code reasonably easily, just
> use gettimeofday before and after ciritcal sections, and sum the results
> from each run.
Yeah, eventually I did that but it isn't nearly as accurate as a
profile. Would certainly like to know how to make gprof work and why
it isn't at any rate for future development. I don't often find the
need to profile, but sometimes I do and not being able to is a big
bummer.
Received on Thu Dec 8 20:15:06 2005
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