Build failure due to missing sys/sysctl.h

[AI-Pranto]

My system places sysctl.h under /usr/include/linux.

CC=mpicc CXX=mpicxx FC=mpifort cmake -DNEK_DIST=nekrs ../../../..

[ 62%] Building CXX object vendor/nekRS/home/pranto/github/enrico/tests/singlerod/short/build/_deps/occa_content-build/CMakeFiles/libocca.dir/src/tools/sys.cpp.o
/home/pranto/github/enrico/tests/singlerod/short/build/_deps/occa_content-src/src/tools/sys.cpp:16:12: fatal error: sys/sysctl.h: No such file or directory
   16 | #  include <sys/sysctl.h>
      |            ^~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [vendor/nekRS/home/pranto/github/enrico/tests/singlerod/short/build/_deps/occa_content-build/CMakeFiles/libocca.dir/build.make:2932: vendor/nekRS/home/pranto/github/enrico/tests/singlerod/short/build/_deps/occa_content-build/CMakeFiles/libocca.dir/src/tools/sys.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1187: vendor/nekRS/home/pranto/github/enrico/tests/singlerod/short/build/_deps/occa_content-build/CMakeFiles/libocca.dir/all] Error 2
make: *** [Makefile:149: all] Error 2

I didn't see this on ubuntu-20.04.

• OS: POP!_OS 20.10
• kernel: 5.8.0-7630-generic

[RonRahaman]

This is an error from OCCA (the parallel backend in NekRS). I would raise the issue to them: https://github.com/libocca/occa
It's pretty likely that they could fix this by locating the header in the CMake

[AI-Pranto]

@RonRahaman, Any update?

[AI-Pranto]

@RonRahaman I've got the similar error on ubuntu-20.10 too.

[RonRahaman]

Sorry for not getting back to you sooner! So OCCA has addressed this issue:

https://github.com/libocca/occa/pull/432/files#diff-dd832eaf5a2504c8796682e7c123e78446d83478cc01e479931350f8fc2d9df1

However, NekRS uses it's own fork of OCCA, and they haven't merged these upstream changes. I'm trying to get the NekRS folks to update their fork of OCCA, and unfortunately, I'm really not sure what their timeframe will be.

[AI-Pranto]

@RonRahaman I am planning to use nekRS with CUDA backend and OpenMC with all threads(16 threads) in my pc, How can I do this? mpirun -np 1 ../bld/install/bin/enrico It's ok for nekRS because I have only 1GPU but in case of OpenMC I get only 2 threads :(

[RonRahaman]

Have you tried setting the environment variable OMP_NUM_THREADS=16?

[AI-Pranto]

Thanks @RonRahaman :) for pointing this out.

Yeah, Now It's using all 16 threads.