On Mon, Jul 11, 2022 at 7:37 PM Pu Lehui <pulehui@xxxxxxxxxx> wrote: > > kernel/bpf/preload/iterators use bpftool for vmlinux.h, skeleton, and > static linking only. So we can use lightweight bootstrap version of > bpftool to handle these, and it will be faster. > > Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx> > Suggested-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > --- > kernel/bpf/preload/iterators/Makefile | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/kernel/bpf/preload/iterators/Makefile b/kernel/bpf/preload/iterators/Makefile > index bfe24f8c5a20..cf5f39f95fed 100644 > --- a/kernel/bpf/preload/iterators/Makefile > +++ b/kernel/bpf/preload/iterators/Makefile > @@ -9,7 +9,7 @@ LLVM_STRIP ?= llvm-strip > TOOLS_PATH := $(abspath ../../../../tools) > BPFTOOL_SRC := $(TOOLS_PATH)/bpf/bpftool > BPFTOOL_OUTPUT := $(abs_out)/bpftool > -DEFAULT_BPFTOOL := $(OUTPUT)/sbin/bpftool > +DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool > BPFTOOL ?= $(DEFAULT_BPFTOOL) > > LIBBPF_SRC := $(TOOLS_PATH)/lib/bpf > @@ -61,9 +61,14 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OU > OUTPUT=$(abspath $(dir $@))/ prefix= \ > DESTDIR=$(LIBBPF_DESTDIR) $(abspath $@) install_headers > > +ifeq ($(CROSS_COMPILE),) > $(DEFAULT_BPFTOOL): $(BPFOBJ) | $(BPFTOOL_OUTPUT) > $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOL_SRC) \ > OUTPUT=$(BPFTOOL_OUTPUT)/ \ > - LIBBPF_OUTPUT=$(LIBBPF_OUTPUT)/ \ > - LIBBPF_DESTDIR=$(LIBBPF_DESTDIR)/ \ > - prefix= DESTDIR=$(abs_out)/ install-bin > + LIBBPF_BOOTSTRAP_OUTPUT=$(LIBBPF_OUTPUT)/ \ > + LIBBPF_BOOTSTRAP_DESTDIR=$(LIBBPF_DESTDIR)/ bootstrap > +else > +$(DEFAULT_BPFTOOL): | $(BPFTOOL_OUTPUT) > + $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOL_SRC) \ > + OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap > +endif another idea (related to my two previous comments for this patch set), maybe we can teach bpftool's Makefile to reuse LIBBPF_OUTPUT as LIBBPF_BOOTSTRAP_OUTPUT, if there is no CROSS_COMPILE? Then we can keep iterators/Makefile, samples/bpf/Makefile and runqslower/Makefile simpler and ignorant of CROSS_COMPILE, but still get the benefit of not rebuilding libbpf unnecessarily in non-cross-compile mode? > -- > 2.25.1 >
