On Tue, Nov 22, 2011 at 7:53 PM, Josh Blum
<address@hidden> wrote:
On 11/22/2011 04:20 PM, Jordan Otomo wrote:
> Hi,
>
> I'm having issues using the hier_block2. When I create a flowgraph
> consisting of roughly 12 blocks, I don't get any overruns. However,
> combining blocks (e.g. source -> hier_block2 -> sink) results in a
> ton of overruns. The parameters of the individual blocks that have
> been combined into the hier_block2 have not changed. Does the
> hier_block2 wait for the work function of each of the blocks it
> encompasses to return before producing outputs/requesting more
> inputs? Any thoughts or advice would be greatly appreciated.
>
Your saying that a flow graph of *identical* topology has *different*
performance when moving some of the blocks into a hier block?
If thats the case, its hard to believe. The the flow graph is run, its
essentially flattened. There is no difference to the scheduler or
buffers whether or not hierarchical blocks were used.
-josh
Yep, what Josh said. If this really is the case, though, it's definitely a problem. Instead of using USRPs and looking at the overruns as your benchmark, could you put in a signal source and a gr_head block of some number of samples (10 to 100 million or so, enough to get a good measurement) and switch out your sinks for null_sinks. Run the program and time it between the non-hier block and the hier block version and let us know what you get.
Thanks,
Tom