[PATCH v1 07/14] perf build: Move static libbpf dependency out of prepare step

[Ian Rogers]

The prepare step is a large serialization point before parallel
sub-makes build the perf tool. The libbpf headers are used in the
bench and util libraries, as well as individual perf builtin
commands. Move the libbpf dependency out of the prepare step and into
the dependencies for those targets to avoid it being a source of
serialization in the prepare step.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/Makefile.perf | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index ec0e91bedce1..5af767415c11 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -547,7 +547,7 @@ export NO_JEVENTS
 
 build := -f $(srctree)/tools/build/Makefile.build dir=. obj
 
-$(PERF_IN): prepare FORCE
+$(PERF_IN): prepare $(LIBBPF) FORCE
 	$(Q)$(MAKE) $(build)=perf
 
 $(LIBPMU_EVENTS_IN): FORCE $(LIBPERF)
@@ -558,7 +558,7 @@ $(LIBPMU_EVENTS): $(LIBPMU_EVENTS_IN)
 
 # The $(LIBPERF_UTIL) dependency is to ensure bpftool and vmlinux.h
 # aren't racily built for bench/bpf_skel/bench_uprobe.bpf.c
-$(LIBPERF_BENCH_IN): FORCE prepare | $(LIBPERF_UTIL)
+$(LIBPERF_BENCH_IN): FORCE prepare $(LIBBPF) | $(LIBPERF_UTIL)
 	$(Q)$(MAKE) $(build)=perf-bench
 
 $(LIBPERF_BENCH): $(LIBPERF_BENCH_IN)
@@ -576,7 +576,7 @@ $(LIBPERF_UI_IN): FORCE prepare
 $(LIBPERF_UI): $(LIBPERF_UI_IN)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $<
 
-$(LIBPERF_UTIL_IN): FORCE prepare
+$(LIBPERF_UTIL_IN): FORCE prepare $(LIBBPF)
 	$(Q)$(MAKE) $(build)=perf-util
 
 $(LIBPERF_UTIL): $(LIBPERF_UTIL_IN)
@@ -636,10 +636,6 @@ prepare: $(OUTPUT)PERF-VERSION-FILE \
 	$(LIBSUBCMD) \
 	$(LIBSYMBOL)
 
-ifdef LIBBPF_STATIC
-prepare: $(LIBBPF)
-endif
-
 $(OUTPUT)%.o: %.c prepare FORCE
 	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(build-dir) $@
 
-- 
2.54.0.563.g4f69b47b94-goog