Calling 'info variables' (or args or locals) the last few frames didn't give me any real info so I built a copy of GR/Volk with debug symbols. I ran the FG again, this time from GDB, here's my back trace. In this backtrace you can see the arguments passed in each call. I have an i7-5600U CPU @ 2.60GHz, the volk_profile is appended at the bottom.
Here's are the links for the relevant code: https://github.com/gnuradio/volk/blob/f0b722392950bf7ede7b32f5ff60019bce7a8592/kernels/volk/volk_32fc_x2_multiply_32fc.h#L232 https://github.com/gnuradio/gnuradio/blob/master/gr-filter/lib/fft_filter.cc#L323 https://github.com/gnuradio/gnuradio/blob/222e0003f9797a1b92d64855bd2b93f0d9099f93/gr-digital/lib/corr_est_cc_impl.cc#L214 Could the problem be that nitems is 257 and num_points is 512? Or should nitems really be 256 and not 257? Thanks, Devin (gdb) bt #0 0x00007fffdcaccb57 in volk_32fc_x2_multiply_32fc_a_avx2_fma (__P=0x3b051b0) at /usr/lib/gcc/x86_64-redhat-linux/4.8.5/include/avxintrin.h:835 #1 0x00007fffdcaccb57 in volk_32fc_x2_multiply_32fc_a_avx2_fma (cVector=0x3b1f770, aVector=0x3b051b0, bVector=0x3b240e0, num_points=512) at /local_disk/gr_3.7.9_src/volk/kernels/volk/volk_32fc_x2_multiply_32fc.h:242 #2 0x00007fffdc945a75 in __volk_32fc_x2_multiply_32fc_a (cVector=0x3b1f770, aVector=0x3b051b0, bVector=0x3b240e0, num_points=512) at /local_disk/gr_3.7.9_src/volk/build_debug/lib/volk.c:7010 #3 0x00007fffd3f8e360 in gr::filter::kernel::fft_filter_ccc::filter(int, std::complex<float> const*, std::complex<float>*) (this=0x3b02f40, nitems=nitems@entry=257, input=input@entry=0x7fffc9cc7000, output=output@entry=0x3b36460) at /local_disk/gr_3.7.9_src/gnuradio/gr-filter/lib/fft_filter.cc:323 #4 0x00007fffd42910df in gr::digital::corr_est_cc_impl::work(int, std::vector<void const*, std::allocator<void const*> >&, std::vector<void*, std::allocator<void*> >&) (this=0x3b01560, noutput_items=257, input_items=..., output_items=std::vector of length 1, capacity 1 = {...}) at /local_disk/gr_3.7.9_src/gnuradio/gr-digital/lib/corr_est_cc_impl.cc:237 #5 0x00007fffdd064907 in gr::sync_block::general_work(int, std::vector<int, std::allocator<int> >&, std::vector<void const*, std::allocator<void const*> >&, std::vector<void*, std::allocator<void*> >&) (this=0x3b015b8, noutput_items=<optimized out>, ninput_items=..., input_items=..., output_items=...) at /local_disk/gr_3.7.9_src/gnuradio/gnuradio-runtime/lib/sync_block.cc:66 #6 0x00007fffdd02f70f in gr::block_executor::run_one_iteration() (this=this@entry=0x7fff83ffedb0) at /local_disk/gr_3.7.9_src/gnuradio/gnuradio-runtime/lib/block_executor.cc:438 #7 0x00007fffdd06da8a in gr::tpb_thread_body::tpb_thread_body(boost::shared_ptr<gr::block>, int) (this=0x7fff83ffedb0, block=..., max_noutput_items=<optimized out>) at /local_disk/gr_3.7.9_src/gnuradio/gnuradio-runtime/lib/tpb_thread_body.cc:122 #8 0x00007fffdd062761 in boost::detail::function::void_function_obj_invoker0<gr::thread::thread_body_wrapper<gr::tpb_container>, void>::invoke(boost::detail::function::function_buffer&) (this=0x3bc3ec0) at /local_disk/gr_3.7.9_src/gnuradio/gnuradio-runtime/lib/scheduler_tpb.cc:44 #9 0x00007fffdd062761 in boost::detail::function::void_function_obj_invoker0<gr::thread::thread_body_wrapper<gr::tpb_container>, void>::invoke(boost::detail::function::function_buffer&) (this=0x3bc3ec0) at /local_disk/gr_3.7.9_src/gnuradio/gnuradio-runtime/include/gnuradio/thread/thread_body_wrapper.h:51 #10 0x00007fffdd062761 in boost::detail::function::void_function_obj_invoker0<gr::thread::thread_body_wrapper<gr::tpb_container>, void>::invoke(boost::detail::function::function_buffer&) (function_obj_ptr=...) at /usr/include/boost/function/function_template.hpp:153 #11 0x00007fffdd016cd0 in boost::detail::thread_data<boost::function0<void> >::run() (this=<optimized out>) at /usr/include/boost/function/function_template.hpp:767 #12 0x00007fffdd016cd0 in boost::detail::thread_data<boost::function0<void> >::run() (this=<optimized out>) at /usr/include/boost/thread/detail/thread.hpp:117 #13 0x00007fffdbe4f24a in thread_proxy () at /lib64/libboost_thread-mt.so.1.53.0 #14 0x00007ffff7800dc5 in start_thread () at /lib64/libpthread.so.0 #15 0x00007ffff6e2528d in clone () at /lib64/libc.so.6 Here are the locals on the last few frames: (gdb) f 0 #0 0x00007fffdcaccb57 in _mm256_load_ps (__P=0x3b051b0) at /usr/lib/gcc/x86_64-redhat-linux/4.8.5/include/avxintrin.h:835 835 return *(__m256 *)__P; (gdb) info locals No locals. (gdb) f 1 #1 volk_32fc_x2_multiply_32fc_a_avx2_fma (cVector=0x3b1f770, aVector=0x3b051b0, bVector=0x3b240e0, num_points=512) at /local_disk/gr_3.7.9_src/volk/kernels/volk/volk_32fc_x2_multiply_32fc.h:242 242 const __m256 x = _mm256_load_ps((float*)a); // Load the ar + ai, br + bi as ar,ai,br,bi (gdb) info locals y = {-4.87433296e+17, 4.59163468e-41, -3.92813517e+17, 4.59163468e-41, 5.15677835e-43, 0, 5.26888223e-43, 0} tmp2x = {6.389921e-43, 0, -512.314453, 4.59163468e-41, 1.26116862e-44, 0, -4.87433296e+17, 4.59163468e-41} x = {-512.314453, 4.59163468e-41, 0, 0, 2.76102662, -3.64918089, -4.92134571, -1.06491208} yl = {4.14784345e-43, 0, 1.26116862e-44, 0, -4.87442367e+17, 4.59163468e-41, -4.87439343e+17, 4.59163468e-41} yh = {-1674752, 4.59163468e-41, 0, 0, -1.50397414e-36, 4.59163468e-41, -3.31452625e+17, 4.59163468e-41} tmp2 = {6.72623263e-44, 1.2751816e-43, 2.24207754e-44, 0, 7.17464814e-43, 0, -3.31440427e+17, 4.59163468e-41} z = {0.794147611, 0, 0.263988227, 0, -0.380019426, 0, -0.953325868, 0} number = 0 quarterPoints = 128 c = 0x3b1f770 a = 0x3b051b0 b = 0x3b240e0 (gdb) f 2 #2 0x00007fffdc945a75 in __volk_32fc_x2_multiply_32fc_a (cVector=0x3b1f770, aVector=0x3b051b0, bVector=0x3b240e0, num_points=512) at /local_disk/gr_3.7.9_src/volk/build_debug/lib/volk.c:7010 7010 volk_32fc_x2_multiply_32fc_a(cVector, aVector, bVector, num_points); (gdb) info locals No locals. (gdb) f 3 #3 0x00007fffd3f8e360 in gr::filter::kernel::fft_filter_ccc::filter (this=0x3b02f40, nitems=nitems@entry=257, input=input@entry=0x7fffc9cc7000, output=output@entry=0x3b36460) at /local_disk/gr_3.7.9_src/gnuradio/gr-filter/lib/fft_filter.cc:323 323 volk_32fc_x2_multiply_32fc_a(c, a, b, d_fftsize); (gdb) info locals a = <optimized out> b = <optimized out> c = <optimized out> i = 0 dec_ctr = 0 j = <optimized out> ninput_items = 257 My volk profile results: $ volk_profile -R 32fc_x2_multiply Using Volk machine: avx2_64_mmx_orc RUN_VOLK_TESTS: volk_32fc_x2_multiply_32fc(131071,1987) u_avx2_fma completed in 220ms u_avx completed in 220ms u_sse3 completed in 240ms generic completed in 2810ms a_avx2_fma completed in 200ms a_avx completed in 220ms a_sse3 completed in 230ms a_generic completed in 2810ms u_orc completed in 280ms Best aligned arch: a_avx2_fma Best unaligned arch: u_avx2_fma RUN_VOLK_TESTS: volk_32fc_x2_multiply_conjugate_32fc(131071,1987) u_avx completed in 230ms u_sse3 completed in 230ms generic completed in 2790ms a_avx completed in 220ms a_sse3 completed in 230ms a_generic completed in 2800ms Best aligned arch: a_avx Best unaligned arch: u_avx Writing "/home/devin/.volk/volk_config"... On Mon, Mar 7, 2016 at 10:38 PM, West, Nathan <n...@ostatemail.okstate.edu> wrote: > On Mon, Mar 7, 2016 at 10:18 PM, West, Nathan <n...@ostatemail.okstate.edu > > wrote: > >> On Mon, Mar 7, 2016 at 2:32 PM, devin kelly <dwwke...@gmail.com> wrote: >> >>> Hello, >>> >>> I've built a flowgraph (grc, python attached) that usually (but not >>> always) produces a segfaults in volk_32fc_x2_multiply_32fc_a_avx2_fma. The >>> segfault occurs in the FFT filter in correlation estimator block. I'm not >>> sure if it's the Volk code that's causing the segfault or the GR code >>> calling it or what I'm putting into GR. I've got a back trace below if >>> that helps. >>> >>> Also, at the tag gate in my flowgraph I would usually have a USRP >>> transmitter and a USRP receiver in a before the Correlation Estimate in a >>> separate flowgraph but since I can re-create the segfault in the flowgraph >>> I simplified. >>> >>> I'm using GR 3.7.9, Volk 1.2.1 and UHD 3.9.2 (though I don't call any >>> UHD code here). >>> >>> Thanks for any help, >>> Devin >>> >>> $ gdb /usr/bin/python core.13408 >>> GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-80.el7 >>> Copyright (C) 2013 Free Software Foundation, Inc. >>> License GPLv3+: GNU GPL version 3 or later < >>> http://gnu.org/licenses/gpl.html> >>> This is free software: you are free to change and redistribute it. >>> There is NO WARRANTY, to the extent permitted by law. Type "show >>> copying" >>> and "show warranty" for details. >>> This GDB was configured as "x86_64-redhat-linux-gnu". >>> For bug reporting instructions, please see: >>> <http://www.gnu.org/software/gdb/bugs/>... >>> Reading symbols from /usr/bin/python2.7...Reading symbols from >>> /usr/bin/python2.7...(no debugging symbols found)...done. >>> (no debugging symbols found)...done. >>> >>> [Thread debugging using libthread_db enabled] >>> Using host libthread_db library "/lib64/libthread_db.so.1". >>> Core was generated by `python2 ./segfault_test.py'. >>> Program terminated with signal 11, Segmentation fault. >>> #0 0x00007f11a4d064c0 in volk_32fc_x2_multiply_32fc_a_avx2_fma () from >>> /local_disk/gr_3.7.9/lib/libvolk.so.1.2.1 >>> Missing separate debuginfos, use: debuginfo-install >>> python-2.7.5-34.el7.x86_64 >>> (gdb) bt >>> #0 0x00007f11a4d064c0 in volk_32fc_x2_multiply_32fc_a_avx2_fma () at >>> /local_disk/gr_3.7.9/lib/libvolk.so.1.2.1 >>> #1 0x00007f119c1d0006 in >>> gr::filter::kernel::fft_filter_ccc::filter(int, std::complex<float> const*, >>> std::complex<float>*) () >>> at /local_disk/gr_3.7.9/lib64/libgnuradio-filter-3.7.9.so.0.0.0 >>> #2 0x00007f119c4d724f in gr::digital::corr_est_cc_impl::work(int, >>> std::vector<void const*, std::allocator<void const*> >&, std::vector<void*, >>> std::allocator<void*> >&) () at >>> /local_disk/gr_3.7.9/lib64/libgnuradio-digital-3.7.9.so.0.0.0 >>> #3 0x00007f11a52b1f57 in gr::sync_block::general_work(int, >>> std::vector<int, std::allocator<int> >&, std::vector<void const*, >>> std::allocator<void const*> >&, std::vector<void*, std::allocator<void*> >>> >&) () at /local_disk/gr_3.7.9/lib64/libgnuradio-runtime-3.7.9.so.0.0.0 >>> #4 0x00007f11a527a6bd in gr::block_executor::run_one_iteration() () at >>> /local_disk/gr_3.7.9/lib64/libgnuradio-runtime-3.7.9.so.0.0.0 >>> #5 0x00007f11a52baf60 in >>> gr::tpb_thread_body::tpb_thread_body(boost::shared_ptr<gr::block>, int) () >>> at /local_disk/gr_3.7.9/lib64/libgnuradio-runtime-3.7.9.so.0.0.0 >>> #6 0x00007f11a52aebc1 in >>> boost::detail::function::void_function_obj_invoker0<gr::thread::thread_body_wrapper<gr::tpb_container>, >>> void>::invoke(boost::detail::function::function_buffer&) () at >>> /local_disk/gr_3.7.9/lib64/libgnuradio-runtime-3.7.9.so.0.0.0 >>> #7 0x00007f11a5260910 in >>> boost::detail::thread_data<boost::function0<void> >::run() () >>> at /local_disk/gr_3.7.9/lib64/libgnuradio-runtime-3.7.9.so.0.0.0 >>> #8 0x00007f11a40b824a in thread_proxy () at >>> /lib64/libboost_thread-mt.so.1.53.0 >>> #9 0x00007f11bfa38dc5 in start_thread () at /lib64/libpthread.so.0 >>> #10 0x00007f11bf05d28d in clone () at /lib64/libc.so.6 >>> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> >> I couldn't reproduce this on my machine with avx2. Your GRC flowgraph >> didn't draw anything, so I replaced your FG with random source(0,255) -> >> const. modulator -> correlation est -> sinks. >> >> I'm wondering if a bad vector length is getting passed in by accident. >> Can you get the parameters to the VOLK call when it crashes? If you're not >> familiar with gdb do something like the following: >> gdb> f 0 >> gdb> info variables >> > > > Also, I'd like to know what processor you have. I don't think it has > anything to do with this bug, but my processor (i7-4700MQ) doesn't > generally see much benefit from AVX much less AVX2. What were the times > volk_profile gives you for this kernel? (use volk_profile -R > 32fc_x2_multiply) >
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