Re: [Discuss-gnuradio] Ring-buffer allocation

[Marcus D. Leech]

Eric Blossom wrote:
>
> OK.  It may no longer be double buffering, so your throughput may be
> down.  But, hey, if it's working :-)
>
> Eric
>
>   
OK, so I looked into this further.  If I work backwards from the
file-sink back to the USRP, I have
  a float vector of 16e6 items, which was costing 250e6, a complex
vector of 16e6 items, which was
  costing 500e6, another 16e6 complex vector costing 500e6, and a
complex stream of 32e6 items, costing
  250e6 memory.

I added logic to gr_flat_flowgraph::allocate_buffer   so that if nitems
>= 4 and item_size >= 1<<2, then
     nitems /= 2.

That reduced the memory footprint considerably, and still gives you
double buffering between blocks.


-- 
Marcus Leech
Principal Investigator, Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org