Re: How to get profile data?

Grzegorz B. Prokopski wrote:
> On Tue, 2004-10-26 at 09:50, Chris Pickett wrote:
> 
>>Grzegorz B. Prokopski wrote:
>>
>>>On Mon, 2004-10-25 at 22:33, fei yang wrote:
>>>
>>>>   I am a student coming from China and I am interesting in GC
>>>>Algorithm. Now I write a new algorithm based sablevm1.0.9(include
>>>>three parts: class-library-1.0.9, native-library-1.0.9, sablevm-1.0.9)
>>>>in RedHat 7.3, with gcc 2.96. but I can't get profile data.
>>>
>>>Firstly, 1.0.9 is *very* old.  You should really be using latest
>>>released version, which ATM is 1.1.6.  Or, it might turn out, that in
> 
> [...]
> 
>>>In current development versions I added --with-profiling= configure
>>>switch, that has two values "gprof" or "nostatic".  If you want to
>>>use gprof, just use --with-profiling=gprof.  If you want to use
>>>qprof - you'll need to pass --with-profiling=nostatic.  This switch
>>>will remove "static" keyword from definitions of many functions of
>>>libsablevm, making the functions visible to outside worlds and also
>>>profiler (i.e. qprof).
>>
>>Thanks.  Note that when I was profiling I could never get gprof to work 
>>properly with SableVM -- it doesn't support multiple threads.
> 
> 
> Actually I don't think SVM 1.0.9 made such extensive use of "static"
> keyword as newer versions, so I tend to believe the problem reported
> by the original sender was actually a problem with gprof being unable
> to track calls made by library.
> 
> So actually it should be possible to profile 1.0.9 quite easily with
> any reasonable profiler.  I think we should also note that RH 7.3 is
> *heavily* obsolete, and so is gprof in gcc 2.96.

Well, I tried every profiler I could find and the only useful one was 
qprof.  Again see that CHANGES file in my sandbox for details (I really 
should rename the file, but whatever).

Out-of-the-box gprof does not work with multithreaded systems [1], you 
need a patch [2].  Even with the patch applied, I still couldn't get it 
to work (whereas I got usable results out of qprof, even with the static 
and inline keywords there, because I hadn't used them for my own code).

[1] http://www.kegel.com/gprof.html
[2] http://sam.zoy.org/writings/programming/gprof.html

Really, qprof is the only good userland tool (OProfile and Prospect 
would probably be okay too, but need root/kernel access to install and 
are a pain).  It's a shame it's not maintained or packaged very well.  I 
think I wrote about all this on the mailing list at the time as well.

Cheers,
Chris