-pg profiling instrumentation question

Juan Carlos Franzoy jfranzoy@yahoo.com.ar
Thu Jan 24 15:10:00 GMT 2008


Hello. I have already post this message on a gcc mailing list. I was told to post it here.

I am having problems profiling an application. I think the problem is that one of our libraries break -pg instrumentation. This library hide portabilities issues under a portable interface, allowing us to run in console mode, in daemon mode  in unices or as a service in windows. As you may guess, it is a complex library that do a lot of things. I do not know which of these may be hurting -pg.

This pseudocode is a description of what I am doing.

void a() {}
void b() { for(int i=0; i < 10000; ++i) a(); }
void f() {}
void g() { for(int i=0; i < 10000; ++i) f(); }

class MyModule() ... {
public:
    ...
    void operator()() {
         ...
         // *2
         for(int i=0; i < 10000; ++i) g();
         return;
    }
} myModule( .... );

int main() {
   ...
   // *1
   for(int i=0; i < 10000; ++i) b();
   mylib::registerModule(myModule);
   mylib::run(); // create a thread per module
   ...
}

The problem is that the profiling information contain time information for b() and a() but no for g() and f(). On the other hand the call count is the same. 

--- gprof output ---
Flat profile:
Each sample counts as 0.01 seconds.
   %     self                           self          total
 time  seconds    calls         ms/call  ms/call  name
50.00    0.22     10000            0.02     0.04         a()
29.55    0.13    100000000     0.00     0.00         b()
20.45    0.09    1                 90.00   90.00       _static_init
 0.00      0.00    100000000    0.00     0.00        f()
 0.00      0.00     10000            0.00     0.00        g()
...
--- end of gprof output ---

Note: I already try making a sigprocmask, pthread_mask to unblock SIGPROF in *1 and *2. I also verifíed that the signal handler of SIGPROF is the same in *1 and *2, it is a valid pointer, not SIG_DFL nor SIG_IGN. I also tried to add a call to moncontrol(1) in *2. This seems to work, at least it displays something != 0 in %time column.

If somebody can help will make me happy. Thanks.


Juan Carlos.




      Tarjeta de crédito Yahoo! de Banco Supervielle.
Solicitá tu nueva Tarjeta de crédito. De tu PC directo a tu casa. www.tuprimeratarjeta.com.ar



More information about the Binutils mailing list