Cannot get makefile to produce gmon.out

Question

I am trying to profile my code since I can't figure out what is slowing it down. I have the following makefile:

CXX=gcc
RM=rm -f
CFLAGS=-pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64
LDFLAGS=-pg -lpthread `pkg-config fuse --cflags --libs`
EXEC = fs

SRCS=$(shell echo *.c)
OBJS=$(subst .c,.o,$(SRCS))

all: $(EXEC)

$(EXEC): $(OBJS)
        $(CXX) $(LDFLAGS) -o $(EXEC) $(OBJS)

%.o: %.c
        $(CXX) $(CFLAGS) -c -o $@ $^

clean:
        $(RM) *.o
        $(RM) $(EXEC)

which produces this output:

gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o datablock.o datablock.c
gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o disk.o disk.c
gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o fsinterface.o fsinterface.c
gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o inode.o inode.c
gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o main.o main.c
main.c:19: warning: initialization from incompatible pointer type
gcc -pg -DNDEBUG -O3 -g3 -O0 -D_FILE_OFFSET_BITS=64 -c -o mkfs.o mkfs.c
gcc -pg -lpthread `pkg-config fuse --cflags --libs` -o fs datablock.o disk.o fsinterface.o inode.o main.o mkfs.o
[root@ip-10-2-176-50 fusefilesystemclean]# gprof fs
gmon.out: No such file or directory

and I can't seem to get a gmon.out file to be produce. I am not very good wuth Makefiles. Can someone help me?

Thanks.

Answer 1

The gmon.out file is not created until you run your program.

The -pg switch just adds the calls to create the gmon.out file when the program is run.

Run your program:

fs

Then run gprof:

gprof 

Read the man page for gprof