| Message ID | 20210313210920.1959628-5-andrii@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | Build BPF selftests and its libbpf, bpftool in debug mode | expand |
On Sat, Mar 13, 2021 at 1:09 PM Andrii Nakryiko <andrii@kernel.org> 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@kernel.org> > --- > 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 >
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=$(HOSTLD) \ + EXTRA_CFLAGS='-g -Og' \ OUTPUT=$(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
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@kernel.org> --- tools/testing/selftests/bpf/Makefile | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)