I've been trying out the (bleeding edge) corr_est() code and the test_corr_est.grc sometimes segvs. Not repeatable, won't crash under gdb :-) From a core file, it's crashing loading the first element of aVector in volk_32fc_x2_multiply_32fc_a_avx instruction is vmovaps (%eax),%ymm1 where eax is 0x8b8b590.
My CPU supports the 256bit AVX instructions, and I believe such data needs to be 256bit=32 byte aligned. EAX here isn't. Looking at the backtrace, it's crashing in fft_filter_ccc::filter, where the d_fwdfft is generated from fft::fft_complex In turn this creates d_inbuf by calling fftwf_malloc. I believe this only guarantees 16 byte alignment. (I'm on fftw3.3.4, on a 32 bit Linux 3.18.1, CPU Intel i5-3470) As we move to use volk and the fast SIMD, should the code in fft.cc (and perhaps other places) move to using a volk memory allocator to get the right alignment, rather than fftwf_malloc? I'm on gentoo, so I could fix the source to fftwf_malloc to return 32 byte aligned, but that's not a general solution. I'm not sure how I should report this issue, please pass on my report if there's a better place to discuss such things -- G8SQH <djch-gnura...@hutchhome.co.uk> _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
