Re: Symbols not decoded in 0.0.2.PERF

[Johan Tibell <johan.tibell@gmail.com>]

On Tue, Apr 19, 2011 at 1:22 PM, Johan Tibell <johan.tibell@gmail.com> wrote:
> * It could be the case that GHC is generating symbols that perf cannot
> interpret somehow. If we can confirm this is the case we can try to
> fix that.

I spent the day making sure this is not the case. All the Haskell
functions now have the correct (fingers crossed) .type and .size ELF
directives:

    74.18%            bench  ./bench               [.] 0x000000002ac524
     7.19%            bench  /lib/libc-2.11.1.so   [.] memcpy
     4.53%            bench  ./bench               [.] s1Ok_info
     4.28%            bench  ./bench               [.] s1Ol_info
     3.28%            bench  ./bench               [.] allocate
     0.74%            bench  ./bench               [.] Main_zdwa_info
     0.62%            bench  ./bench               [.] memcpy@plt
     0.45%            bench  ./bench               [.] clearNurseries
     0.36%            bench  ./bench               [.] evacuate
     0.27%            bench  ./bench               [.] stg_newArrayzh

Entries 3-6 and 8-10 are Haskell functions. The top entry is still unknown.

If it matters, the little program I'm running stresses array copying
and I would expect it to spend most of its time in memcpy, but these
numbers suggests that it isn't. Could it be some stripped C libraries
or some code generated by gcc specially for memcpy that's accounting
for the top entry?

Johan