Re: [Discuss-gnuradio] Performance on ARM Cortex-A8

[Thomas Tsou]

On Wed, Jul 13, 2011 at 1:40 AM, Riadh Elloumi <address@hidden> wrote:
> Hi all,
>
> I complied DAB demodulation for ARM Cortex-A8 (TI OMAP 3). It
> successfully demodulate DAB+ but spends 13 seconds decoding 1 second of
> radio baseband (USRP file).

I tested the demodulator with similar results. Decoding a file that
takes a few seconds on my desktop takes over a minute on the ARM.

> Why is gnu radio too slow demodulating DAB+? Do you have some figures of
> CPU consumption on ARM Cortex cores? Is there some optimization I missed
> for the platform?

The performance limitation in this case largely comes from floating
point math performance, though that's a vague and not particularly
useful conclusion.

OProfile report:

http://ttsou.github.com/gnuradio/dab_demod_oprof.txt

OProfile report with symbols:

http://ttsou.github.com/gnuradio/dab_demod_symbols.txt

  Thomas

Profiling through timer interrupt
          TIMER:0|
  samples|      %|
------------------
     3542 28.4727 libm-2.12.2.so
     2976 23.9228 libgnuradio-core-3.4.1git.so.0.0.0
     1637 13.1592 no-vmlinux
     1151  9.2524 libgcc_s.so.1
     1130  9.0836 libgnuradio-dab-3.3.0.so.0.0.0
      758  6.0932 libfftw3f.so.3.2.4
      549  4.4132 libc-2.12.2.so
      407  3.2717 libpthread-2.12.2.so
      120  0.9646 libpython2.6.so.1.0
       82  0.6592 libboost_thread.so.1.45.0
       72  0.5788 python
                  TIMER:0|
          samples|      %|
        ------------------
               72 100.000 [vectors] (tgid:8032 range:0xffff0000-0xffff1000)
        6  0.0482 ld-2.12.2.so
        5  0.0402 busybox
        3  0.0241 time.so
        2  0.0161 oprofiled

  Thomas