On 06/29/2010 01:37 PM, Eric Blossom wrote: > The place to add some debugging outout would be > gr_flat_flowgraph.cc::allocate_buffer. Something like: > > std::cout << "allocate_buffer " << block > << " nitems " << nitems << " item_size " << item_size << > std::endl; > > > For the case of the 6M bin FFT, I could see us getting to > > 6M * sizeof(gr_complex) * 2 * 2 --> 192MB. Not that big. > > > Add the debugging output and let us know what you find. > > allocate_buffer complex_to_mag(1) nitems 4 item_size 25000000 gr_buffer::allocate_buffer: warning: tried to allocate 4 items of size 25000000. Due to alignment requirements 64 were allocated. If this isn't OK, consider padding your structure to a power-of-two bytes. On this platform, our allocation granularity is 4096 bytes. gr_vmcircbuf_sysv_shm: shmget (1): Invalid argument gr_buffer::allocate_buffer: failed to allocate buffer of size 1562500 KB terminate called after throwing an instance of 'std::bad_alloc' what(): std::bad_alloc
This is the complex_to_mag(1) right after the HUGE FFT. That item size must be the size of the *output* vector (6M * sizeof(float) + 'slop'??). Now, see what happens? It's rounding up that 4 items to 64 items, which is ballooning out the request size considerably!! -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
