Re: [gnugo-devel] weird performance problem

[Paul Pogonyshev]

Arend wrote:
> 
> Tracking back some spurious 50% slowdowns for regression runs,
> I found out (with oprofile) that 50% of CPU time was spent in libc.
> Not completely reproducable, however. In particular, I cannot
> reproduce it when linked against libc_p (profiled version) instead of
> libc.
> 
> According to top, gnugo is running with over 90% of CPU time, so
> it should be caused by gnugo.
> Does anybody have any idea what could cause this? Below is a flat
> profile of libc during such a run (according to oprofile). An update
> from SuSE 8.2 to 9.0 didn't solve the problem. 
> 
> Arend
> 
> 
> Profiling through timer interrupt
> samples  %        symbol name
> 6769     86.3393  __mcount_internal
> 665       8.4821  mcount
> 189       2.4107  __i686.get_pc_thunk.bx
> 170       2.1684  memset
> 27        0.3444  memcpy
> 6         0.0765  _int_malloc
> 3         0.0383  __GI___mbrtowc
> 2         0.0255  _int_free
> 1         0.0128  __GI___gettimeofday_internal
> 1         0.0128  __GI__dl_mcount_wrapper_check
> 1         0.0128  __malloc
> 1         0.0128  __realloc
> 1         0.0128  _int_realloc
> 1         0.0128  _nl_explode_name
> 1         0.0128  _nl_make_l10nflist
> 1         0.0128  index
> 1         0.0128  strlen

This is not very helpful.  Can't say anything without call tree.

Btw, `libc' is not `glibc' i.e. not GNU libc, right?

Paul