On Sat, Mar 13, 2021 at 1:09 PM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > Build selftests, bpftool, and libbpf in debug mode with DWARF data to > facilitate easier debugging. > > In terms of impact on building and running selftests. Build is actually faster > now: > > BEFORE: make -j60 380.21s user 37.87s system 1466% cpu 28.503 total > AFTER: make -j60 345.47s user 37.37s system 1599% cpu 23.939 total > > test_progs runtime seems to be the same: > > BEFORE: > real 1m5.139s > user 0m1.600s > sys 0m43.977s > > AFTER: > real 1m3.799s > user 0m1.721s > sys 0m42.420s > > Huge difference is being able to debug issues throughout test_progs, bpftool, > and libbpf without constantly updating 3 Makefiles by hand (including GDB > seeing the source code without any extra incantations). > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > --- > tools/testing/selftests/bpf/Makefile | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index c3999587bc23..d0db2b673c6f 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -21,7 +21,7 @@ endif > > BPF_GCC ?= $(shell command -v bpf-gcc;) > SAN_CFLAGS ?= > -CFLAGS += -g -rdynamic -Wall -O2 $(GENFLAGS) $(SAN_CFLAGS) \ > +CFLAGS += -g -Og -rdynamic -Wall $(GENFLAGS) $(SAN_CFLAGS) \ > -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \ > -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT) \ > -Dbpf_prog_load=bpf_prog_test_load \ > @@ -201,6 +201,7 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ > $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/bpftool > $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ > CC=$(HOSTCC) LD=$(HOSTLD) \ > + EXTRA_CFLAGS='-g -Og' \ I was asked about '-Og' flag and the minimum GCC version that supports it. It seems it was added in GCC 4.8 ([0]), so given the kernel's minimum version is GCC 4.9, we shouldn't need take any extra precautions to handle older compilers. [0] https://gcc.gnu.org/gcc-4.8/changes.html > OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \ > prefix= DESTDIR=$(HOST_SCRATCH_DIR)/ install > > @@ -218,6 +219,7 @@ $(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \ > ../../../include/uapi/linux/bpf.h \ > | $(INCLUDE_DIR) $(BUILD_DIR)/libbpf > $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \ > + EXTRA_CFLAGS='-g -Og' \ > DESTDIR=$(SCRATCH_DIR) prefix= all install_headers > > ifneq ($(BPFOBJ),$(HOST_BPFOBJ)) > @@ -225,7 +227,8 @@ $(HOST_BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \ > ../../../include/uapi/linux/bpf.h \ > | $(INCLUDE_DIR) $(HOST_BUILD_DIR)/libbpf > $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) \ > - OUTPUT=$(HOST_BUILD_DIR)/libbpf/ CC=$(HOSTCC) LD=$(HOSTLD) \ > + EXTRA_CFLAGS='-g -Og' \ > + OUTPUT=$(HOST_BUILD_DIR)/libbpf/ CC=$(HOSTCC) LD=$(HOSTLD) \ > DESTDIR=$(HOST_SCRATCH_DIR)/ prefix= all install_headers > endif > > -- > 2.24.1 >
