Why is my GPU utilization at 0 even though my stdpar feature is supposed to be using the GPU?

[Ehu1]

I am using nvc++ to compile the LULESH benchmark, and from the memory usage, it appears that my benchmark is utilizing the GPU. However, the GPU utilization is showing as 0%.

nvc++ --version

nvc++ 24.9-0 64-bit target on x86-64 Linux -tp sapphirerapids 
NVIDIA Compilers and Tools
Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES.  All rights reserved.

 cat Makefile 
# Build with nvc++, with parallel algorithm support turned on.

SHELL = /bin/sh
.SUFFIXES: .cc .o

LULESH_EXEC = lulesh2.0

CXX = nvc++

SOURCES2.0 = \
        lulesh.cc \
        lulesh-comm.cc \
        lulesh-viz.cc \
        lulesh-util.cc \
        lulesh-init.cc
OBJECTS2.0 = $(SOURCES2.0:.cc=.o)

CXXFLAGS = -w -fast -Mnouniform -Mfprelaxed -stdpar=gpu -std=c++11 -DUSE_MPI=0
LDFLAGS = $(CXXFLAGS) 

%.o: ../src/%.cc ../src/lulesh.h
        @echo "Building $<"
        $(CXX) -c $(CXXFLAGS) -o $@  $<

all: $(LULESH_EXEC)

$(LULESH_EXEC): $(OBJECTS2.0)
        @echo "Linking"
        $(CXX) $(OBJECTS2.0) $(LDFLAGS) -lm -o $@

run: $(LULESH_EXEC)
        ./lulesh2.0 -p -s 150

clean:
        /bin/rm -f *.o *~ $(OBJECTS) $(LULESH_EXEC)
        /bin/rm -rf *.dSYM

[ericniebler]

Which execution context are you using?