OK, here's my C program: #include <stdio.h> #include <stdlib.h> #include <volk/volk.h> #include <stdint.h>
int main() {
size_t alignment = volk_get_alignment();
uint8_t* ptr;
ptr = (uint8_t*)volk_malloc(1000 * sizeof(uint8_t), alignment);
printf("alignment = %lu, ptr = %x, *ptr = %u\n", alignment, ptr, *ptr);
volk_free((void*)ptr);
ptr = NULL;
return 0;
}
Compile:
$ gcc volk_test.c -o volk_test -lvolk -L/local_disk/gr_3.7.9_debug/lib
It's output:
$ ./volk_test
Using Volk machine: avx2_64_mmx_orc
alignment = 32, ptr = 151b040, *ptr = 00
Also, I've attached the output from the preprocessor, this command:
$ /usr/bin/cc -DHAVE_AVX_CVTPI32_PS -DHAVE_CPUID_H -DHAVE_DLFCN_H
-DHAVE_FENV_H -DHAVE_POSIX_MEMALIGN -DHAVE_XGETBV -Wall -fvisibility=hidden
-g -I/local_disk/gr_3.7.9_src/volk/build_debug/include
-I/local_disk/gr_3.7.9_src/volk/include
-I/local_disk/gr_3.7.9_src/volk/kernels
-I/local_disk/gr_3.7.9_src/volk/build_debug/lib
-I/local_disk/gr_3.7.9_src/volk/lib -I/usr/include/orc-0.4 -E -fPIC -o
volk_malloc_preprocessed -c
/local_disk/gr_3.7.9_src/volk/lib/volk_malloc.c
I just found the compiler step from from doing 'VERBOSE=1 make' then
changed the output and added -E. I attached volk_malloc_preprocessed as
well.
It looks like this is my volk_malloc():
void *volk_malloc(size_t size, size_t alignment)
{
void *ptr;
if (alignment == 1)
return malloc(size);
int err = posix_memalign(&ptr, alignment, size);
if(err == 0) {
return ptr;
}
else {
fprintf(stderr,
"VOLK: Error allocating memory "
"(posix_memalign: error %d: %s)\n", err, strerror(err));
return ((void *)0);
}
}
Devin
On Tue, Mar 8, 2016 at 11:37 AM, West, Nathan <n...@ostatemail.okstate.edu>
wrote:
>
> On Tue, Mar 8, 2016 at 10:58 AM, devin kelly <dwwke...@gmail.com> wrote:
>
>> 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.
>>
>
> Excellent. Thanks for going through that extra step. It really helps.
>
>
>>
>> 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?
>>
>
> I don't think so. I'm not familiar with the details of the fft_filter
> implementations, but usually these things will take in some history if they
> don't have enough points to operate on (in this case 512).
>
> The much more worrying thing is your vector addresses.
>
>
>>
>> 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)
>>
>
> 0x3b1f770 % 32 = 16 (bad)
> 0x3b051b0 % 32 = 16 (bad)
> 0x3b240e0 % 32 = 0 (good)
>
> Unfortunately it looks like volk_get_alignment is returning the wrong
> thing or there's a bug in volk_malloc. Can you tell us what
> volk_get_alignment returns? The easiest thing is probably to write a simple
> C program that prints out the result (hmm, I should add that to
> volk-config-info). I'd also like to know which volk_malloc implementation
> you're using. Unfortunately I don't think we have an easy way to discover
> that (hmm, something else that should be added to volk-config-info). I
> think the best way might be to look at volk_malloc.c intermediate files
> after the preprocessor has done its work.
>
> If you want to move on while we figure this out then you can edit
> ~/.volk/volk_config and replace the avx2_fma with sse3 on the line that has
> this kernel name on it.
>
>
>> 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"...
>>
>>
> Well I'm both jealous and happy that AVX2 is actually an improvement on
> newer processors. Also matches the folklore that these new technologies are
> usually not faster in the first silicon products that they come out in.
>
volk_malloc_preprocessed
Description: Binary data
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