GNU Radio 1.3.1 and SMP

GNU Radio
1

Hi,

Quite some time ago, there are multi core scheduler testing branch for
GNU Radio.

http://lists.gnu.org/archive/html/discuss-gnuradio/2008-07/msg00159.html

Can I do the same with GNU Radio release 3.1.3 and follow the same
instructions mentioned in that mail ? I have actually done that but it
does not seem to distribute the processing among the core on the Intel
Atom 330 motherboard.

Regards,
Hew

2

Hew How Chee wrote:

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Discuss-gnuradio Info Page

Can you actually see the four threads (two hyperthread cores) in the
linux listing (/proc/cpuinfo). Do you have SMP and HT enabled in the
BIOS?

Bob

3

Hi Bob,

cat /proc/cpuinfo give 4 processors.

Did more test on running the same piece of code, which is basically a
modified fm receiver. Usually I see nearly 100% loading on 1 of the 4
processors . But sometimes the load is spread on other processor (e.g.
100% load become 50% load on processor1 and 50% on proccessor2). Is this
random behaviour expected ? I was hoping that I can assign gr block to a
processor specifically so that the load is really well distributed.
Forgive me if this question is obvious as I did not track gnuradio
progress as frequently as I would like to.

Hew

4

On Sun, Mar 15, 2009 at 03:25:28AM -0700, Hew How Chee wrote:

I can assign gr block to a processor specifically so that the load
is really well distributed. Forgive me if this question is obvious
as I did not track gnuradio progress as frequently as I would like
to.

Hew

Hew,

The “thread-per-block” scheduler has been in the trunk for about 6 or
9 months and is enabled by default. It was not included in the 3.1.3
release. It will be in the 3.2 release.

With the thread-per-block scheduler, all SMP/SMT/multicore resources
are automatically used. There is no need (or advantage) in assigning
blocks to particular cores.

Eric

5

Hi Eric,

Thanks for the info. Will be looking forward to release 3.2.

Best regards,
Hew