From: Quentin Monnet Date: Thu, 7 Oct 2021 19:44:36 +0000 (+0100) Subject: samples/bpf: Do not FORCE-recompile libbpf X-Git-Tag: v6.6.17~8953^2~2^2~64^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a60d24e7400247bf21cac451f28961ac800756c6;p=platform%2Fkernel%2Flinux-rpi.git samples/bpf: Do not FORCE-recompile libbpf In samples/bpf/Makefile, libbpf has a FORCE dependency that force it to be rebuilt. I read this as a way to keep the library up-to-date, given that we do not have, in samples/bpf, a list of the source files for libbpf itself. However, a better approach would be to use the "$(wildcard ...)" function from make, and to have libbpf depend on all the .c and .h files in its directory. This is what samples/bpf/Makefile does for bpftool, and also what the BPF selftests' Makefile does for libbpf. Let's update the Makefile to avoid rebuilding libbpf all the time (and bpftool on top of it). Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211007194438.34443-11-quentin@isovalent.com --- diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8c5311d..4c5ad15 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -276,7 +276,7 @@ clean: @find $(CURDIR) -type f -name '*~' -delete @$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool -$(LIBBPF): FORCE | $(LIBBPF_OUTPUT) +$(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT) # Fix up variables inherited from Kbuild that tools/ build system won't like $(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \ LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(BPF_SAMPLES_PATH)/../../ \