What is the libnina?

Libnina is a library used to reduce the energy consumption of OpenMP parallel applications. It has two operation modes: the HW counter collection mode, used to characterize the application behavior; and the CPU frequency control mode, where the reduction of energy consumption becomes possible if memory-bound regions are set to execute with a lower CPU frequency.

Requirements

Libnina requires the acpi-cpufreq driver (instead of the intel_pstate) because it dynamically changes the CPU frequency during runtime. The governor must be the userspace that let’s application-level calls (with the appropriate permissions) to set the CPU frequency. If you are using Grub, you can disable intel_pstate by adding the following line in the /etc/default/grub file.

GRUB_CMDLINE_LINUX_DEFAULT="intel_pstate=disable"

And then update grub.cfg by issuing the following command:

grub-mkconfig -o /boot/grub/grub.cfg

• Check here for further details about disabling =intel_pstate=. You can use the follow command line:

sudo cpupower frequency-info --governors

analyzing CPU 0:
conservative ondemand userspace powersave performance

• In this case, it is possible to use this library, because the userspace governor exists.
• It’s necessary the libpapi, libconfig, and libcpufreq installation. The follow command line may be used:

sudo apt install libpapi-dev -y
sudo apt install libconfig-dev -y
sudo apt install libcpufreq-dev -y

Compilation

cd src
make clean
make

rm -f   libnina.so  db.o libnina.o pomp2_lib.o pomp2_user_region_info.o pomp2_region_info.o opari2_ctc_parser.o modeling_papi.o db.d libnina.d pomp2_lib.d pomp2_user_region_info.d pomp2_region_info.d opari2_ctc_parser.d modeling_papi.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM modeling_papi.c >modeling_papi.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM opari2_ctc_parser.c >opari2_ctc_parser.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM pomp2_region_info.c >pomp2_region_info.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM pomp2_user_region_info.c >pomp2_user_region_info.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM pomp2_lib.c >pomp2_lib.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM libnina.c >libnina.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD -MM db.c >db.d
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o db.o db.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o libnina.o libnina.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o pomp2_lib.o pomp2_lib.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o pomp2_user_region_info.o pomp2_user_region_info.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o pomp2_region_info.o pomp2_region_info.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o opari2_ctc_parser.o opari2_ctc_parser.c
gcc  -Wno-unused-parameter -Wno-unused-variable -fPIC -Wall -Wextra -O3 -g -fopenmp  -DLIBNINA_THREAD   -c -o modeling_papi.o modeling_papi.c
gcc  -o libnina.so db.o libnina.o pomp2_lib.o pomp2_user_region_info.o pomp2_region_info.o opari2_ctc_parser.o modeling_papi.o  -shared -lcpufreq -lpapi -lconfig  

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