On Mon, Jan 10, 2011 at 3:45 PM, Michael Dickens
<address@hidden> wrote:
Without seeing your GRC implementation or Python script & block's implementation code, mostly what I or anyone else can provide is general advice. GNU Radio 3.3.0 uses the thread per block (TBP) scheduler by default; if you're not doing anything else except running the flow-graph (meaning: you don't set special GNU Radio environment variables or use a GNU Radio configuration file), then that's what you're using. The performance of any flow-graph really depends on how complex the flow-graph is, how much data you're trying to push through it, and how fast your processors are able to perform the block's computations. The host OS influences execution speed a little, but mostly its those listed factors that make the difference; that said, I haven't used GNU Radio on Ubuntu in a long time so I cannot talk about that OS specifically (Linux, in general, provides very low OS overhead & more time executing the flow-graph's computations). It might be that your flow-graph is running fast enough already to use just 1 core; does it run in "real time" for what you need? Rewriting a given block to use vector-based instructions (SSE, Altivec, Neon) often dramatically increases the computations / time for that block. As for parallelizing your block, without knowing what it is/does exactly, I would always advise you to break down the computations into smaller pieces and then implement those as blocks (if they are no already), then create the "meta-block" (I forget the exact name of it now; maybe "heir_block2"?) using those. That way, the TBP scheduler will have more to work with and the flow-graph will end up being executed more in parallel. If your block has internal data-feedback, then the meta-block will not work (GNU Radio doesn't "do" data-flow feedback in the flow-graph) & you'll have to find some way of parallelizing your algorithm. There are plenty of good books on this subject. - MLD
On Jan 10, 2011, at 3:11 PM, sirjanselot wrote:
> I am currently using gnuradio 3.3.0 as my version.
> How do I know that my flow-graph is executing in thread per block mode?
>
> As far as I can tell my only 1 core out of the 8 is being used when I run my
> flow-graphs. This is what I see when I run the performance monitor (or
> whatever it is called) in Ubuntu.
>
> So can I parallelize my block without having to create a meta-block as you
> say? I have a lot of for-loops and vector calculations that need to be
> optimized (adaptive fir filters).