How to avoid scheduler error running out of memory to allocate

[Armin Ghani]

Dear community

I've been tackling to fix below scheduler error which it fails to allocate buffer for blocks:

ched: <block ofdm_serializer_vcc (22)> is requesting more input data
  than we can provide.
  ninput_items_required = 960
  max_possible_items_available = 127
  If this is a filter, consider reducing the number of taps.

I'm curious to know how to mitigate such error. This issue has been covered very few but one of the workaround would be to change GR_FIXED_BUFFER_SIZE as much as the error disappears but this is not a good solution since it leads to scheduler sample propagation delays. I welcome every effective and reliable solution despite of being difficult to implement and etc.

Below there are a few solutions that came to my mind but none of them are final solutions:

- Trying to change GR_FIXED_BUFFER_SIZE. This leads to path delays which prevents flow graph to run smoothly

- Trying to remove extra blocks. This is not so effective

- Simplifying block implementation specially those which are implemented in hier-block approach by writing c++ code instead. This is also not so effective

- dividing top-block into smaller top-blocks with fever blocks. Not helpful

I'll be more than happy to hear you back.

Regards.

--

Armin Ghani

Research Engineer | Communication Systems Division (CSD)

aghani@cttc.es | +34 93 645 29 08 (2143)

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)

Av. Carl Friedrich Gauss, 7 - Edifici B4 - PMT

08860 - Castelldefels (Barcelona, Spain)

www.cttc.cat