Make tutorial examples use dynamic linkage. #343
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| @@ -85,6 +85,9 @@ CUOBJ= impl/BroadcastSum.o \ | |||
| $(LIBNAME).a: $(CPPOBJ) $(CUOBJ) | |||
| ar r $@ $^ | |||
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| $(LIBNAME).$(SHAREDEXT): $(CPPOBJ) $(CUOBJ) | |||
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Just a quick heads up, the clean target in 119 should probably consider this file as well.
gpu/Makefile
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| @@ -85,6 +85,9 @@ CUOBJ= impl/BroadcastSum.o \ | |||
| $(LIBNAME).a: $(CPPOBJ) $(CUOBJ) | |||
| ar r $@ $^ | |||
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| $(LIBNAME).$(SHAREDEXT): $(CPPOBJ) $(CUOBJ) | |||
| $(CC) $(LDFLAGS) $(FAISSSHAREDFLAGS) -o $(LIBNAME).$(SHAREDEXT) $^ $(CUDAFLAGS) | |||
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Ok, just found a slightly more serious concern: I was trying to build the GPU examples, but it was constantly failing to link:
/opt/cuda//bin/nvcc -I /opt/cuda//targets/x86_64-linux/include/ -Xcompiler -fPIC -Xcudafe --diag_suppress=unrecognized_attribute -gencode arch=compute_37,code="compute_37" -gencode arch=compute_61,code="compute_61" --std c++11 -lineinfo -ccbin g++-6 -DFAISS_USE_FLOAT16 -o 4-GPU 4-GPU.cpp -Xcompiler \"-Wl,-rpath=../../:../../gpu/\" -L../.. -L../../gpu -lfaiss -lgpufaiss \
-I../../../ -Xcompiler -fopenmp -lcublas -Xlinker /usr/lib64/libopenblas.so.0 \
ld: 4-GPU: hidden symbol `cudaMemcpyAsync' in /opt/cuda//bin/..//lib64/libcudart_static.a(libcudart_static.a.o) is referenced by DSO
ld: final link failed: Bad value
make: *** [Makefile:28: 4-GPU] Error 1
After some research, I found that it can be related to an attempt of a dynamic library to use a statically defined reference from an object that it was not properly linked against, or something along these lines. What solves the problem here is to make libgpufaiss.so dynamically link to cudart and cublas explicitly:
$(CC) -L$(CUDA_ROOT)/lib64 -lcublas -lcudart $(LDFLAGS) $(FAISSSHAREDFLAGS) -o $(LIBNAME).$(SHAREDEXT) $^ $(CUDAFLAGS)This also makes the -lcublas flags in the examples redundant, and can be removed. This is also what I did for the C API.
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Thanks for the writeup @Enet4. I pushed the suggested fixes – could you give it a try?
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@beauby Yes, it works now. 👍
* Add shared lib target for GPU version. * Dynamically link tutorial examples. * Add shared lib to clean target in GPU Makefile. * Add clean target to tutorial examples Makefile. * Minor modifications to tutorial GPU examples.
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