From: Ian Rogers Date: Mon, 18 May 2026 15:46:30 +0000 (-0700) Subject: perf build: Encapsulate vmlinux.h and bpftool in bpf_skel.mak X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9798ac0128daf35cb52ca648b1d93f0d40bd0cf5;p=thirdparty%2Flinux.git perf build: Encapsulate vmlinux.h and bpftool in bpf_skel.mak Currently, bpftool and vmlinux.h are prerequisites of the top-level prepare target in Makefile.perf. This unnecessarily blocks the massive parallel C compilation of libraries (perf-util, perf-ui, pmu-events) during the initial startup phase. Move all bpftool and vmlinux.h generation rules down into tools/perf/bpf_skel.mak to encapsulate BPF tooling completely within the skeleton framework. Remove them entirely from prepare to unblock immediate parallel build execution. To prevent parallel sub-makes (perf-util and perf-bench) from racing to build shared prerequisites concurrently, while maintaining strict directory encapsulation without top-level inclusions, serialize bench after the util static archive finishes using an order-only prerequisite: $(LIBPERF_BENCH_IN): FORCE prepare | $(LIBPERF_UTIL) Reviewed-by: Namhyung Kim Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Tested-by: James Clark Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Chartre Cc: Alexandre Ghiti Cc: Andrii Nakryiko Cc: Ankur Arora Cc: Collin Funk Cc: Costa Shulyupin Cc: Daniel Borkmann Cc: Dapeng Mi Cc: David Sterba Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Eduard Zingerman Cc: Howard Chu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kumar Kartikeya Dwivedi Cc: Leo Yan Cc: Markus Mayer Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Terrell Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ricky Ringler Cc: Song Liu Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Tomas Glozar Cc: Yonghong Song Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 7a0e372824c69..8437c3f72125a 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -681,7 +681,7 @@ ifeq ($(BUILD_BPF_SKEL),1) endif ifndef GEN_VMLINUX_H - VMLINUX_H=$(src-perf)/util/bpf_skel/vmlinux/vmlinux.h + VMLINUX_H_FILE=$(src-perf)/util/bpf_skel/vmlinux/vmlinux.h endif ifndef NO_LIBUNWIND diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 373eae7fb72a5..ec0e91bedce12 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -274,7 +274,7 @@ ifeq ($(PYLINT),1) PYLINT := $(shell which pylint 2> /dev/null) endif -export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF +export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT include $(srctree)/tools/build/Makefile.include @@ -324,7 +324,7 @@ else FEATURE_DUMP_EXPORT := $(realpath $(FEATURES_DUMP)) endif -export prefix bindir sharedir sysconfdir DESTDIR +export prefix bindir sharedir sysconfdir DESTDIR VMLINUX_H_FILE # sparse is architecture-neutral, which means that we need to tell it # explicitly what architecture to check for. Fix this up for yours.. @@ -556,7 +556,9 @@ $(LIBPMU_EVENTS_IN): FORCE $(LIBPERF) $(LIBPMU_EVENTS): $(LIBPMU_EVENTS_IN) $(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $< -$(LIBPERF_BENCH_IN): FORCE prepare +# 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) $(Q)$(MAKE) $(build)=perf-bench $(LIBPERF_BENCH): $(LIBPERF_BENCH_IN) @@ -911,60 +913,11 @@ $(INSTALL_DOC_TARGETS): python-clean: $(python-clean) -SKEL_OUT := $(abspath $(OUTPUT)util/bpf_skel) -SKEL_TMP_OUT := $(abspath $(SKEL_OUT)/.tmp) - -$(SKEL_TMP_OUT) $(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) $(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT): +$(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) $(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT): $(Q)$(MKDIR) -p $@ -ifeq ($(CONFIG_PERF_BPF_SKEL),y) -prepare: $(BPFTOOL) $(SKEL_OUT)/vmlinux.h -BPFTOOL := $(SKEL_TMP_OUT)/bootstrap/bpftool - -$(BPFTOOL): | $(SKEL_TMP_OUT) - $(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool \ - OUTPUT=$(SKEL_TMP_OUT)/ bootstrap - -# Paths to search for a kernel to generate vmlinux.h from. -VMLINUX_BTF_ELF_PATHS ?= $(if $(O),$(O)/vmlinux) \ - $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ - ../../vmlinux \ - /boot/vmlinux-$(shell uname -r) - -# Paths to BTF information. -VMLINUX_BTF_BTF_PATHS ?= /sys/kernel/btf/vmlinux - -# Filter out kernels that don't exist or without a BTF section. -VMLINUX_BTF_ELF_ABSPATHS ?= $(abspath $(wildcard $(VMLINUX_BTF_ELF_PATHS))) -VMLINUX_BTF_PATHS ?= $(shell for file in $(VMLINUX_BTF_ELF_ABSPATHS); \ - do \ - if [ -f $$file ] && ($(READELF) -S "$$file" | grep -q .BTF); \ - then \ - echo "$$file"; \ - fi; \ - done) \ - $(wildcard $(VMLINUX_BTF_BTF_PATHS)) - -# Select the first as the source of vmlinux.h. -VMLINUX_BTF ?= $(firstword $(VMLINUX_BTF_PATHS)) - -ifeq ($(VMLINUX_H),) - ifeq ($(VMLINUX_BTF),) - $(error Missing bpftool input for generating vmlinux.h) - endif -endif - -$(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) $(VMLINUX_H) -ifeq ($(VMLINUX_H),) - $(QUIET_GEN)$(BPFTOOL) btf dump file $< format c > $@ -else - $(Q)cp "$(VMLINUX_H)" $@ -endif - -endif # CONFIG_PERF_BPF_SKEL - bpf-skel-clean: - $(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TMP_OUT) $(SKEL_OUT)/*.skel.h $(SKEL_OUT)/vmlinux.h $(OUTPUT)bench/bpf_skel/*.skel.h $(OUTPUT)bench/bpf_skel/.tmp + $(Q)$(MAKE) -f bpf_skel.mak clean pmu-events-clean: ifeq ($(OUTPUT),) diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak index aa04d8b3ee074..30924ad140c49 100644 --- a/tools/perf/bpf_skel.mak +++ b/tools/perf/bpf_skel.mak @@ -35,6 +35,47 @@ ifneq ($(WERROR),0) CLANG_OPTIONS += -Werror endif +$(BPFTOOL): + $(Q)mkdir -p $(SKEL_TOOL_TMP_OUT) + $(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool OUTPUT=$(SKEL_TOOL_TMP_OUT)/ bootstrap + +# Paths to search for a kernel to generate vmlinux.h from. +VMLINUX_BTF_ELF_PATHS ?= $(if $(O),$(O)/vmlinux) \ + $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ + ../../vmlinux \ + /boot/vmlinux-$(shell uname -r) + +# Paths to BTF information. +VMLINUX_BTF_BTF_PATHS ?= /sys/kernel/btf/vmlinux + +# Filter out kernels that don't exist or without a BTF section. +VMLINUX_BTF_ELF_ABSPATHS ?= $(abspath $(wildcard $(VMLINUX_BTF_ELF_PATHS))) +VMLINUX_BTF_PATHS ?= $(shell for file in $(VMLINUX_BTF_ELF_ABSPATHS); \ + do \ + if [ -f $$file ] && ($(READELF) -S "$$file" | grep -q .BTF); \ + then \ + echo "$$file"; \ + fi; \ + done) \ + $(wildcard $(VMLINUX_BTF_BTF_PATHS)) + +# Select the first as the source of vmlinux.h. +VMLINUX_BTF ?= $(firstword $(VMLINUX_BTF_PATHS)) + +ifeq ($(VMLINUX_H_FILE),) + ifeq ($(VMLINUX_BTF),) + $(error Missing bpftool input for generating vmlinux.h) + endif +endif + +$(VMLINUX_H): $(VMLINUX_BTF) $(BPFTOOL) $(VMLINUX_H_FILE) + $(call rule_mkdir) +ifeq ($(VMLINUX_H_FILE),) + $(QUIET_GEN)$(BPFTOOL) btf dump file $< format c > $@ +else + $(Q)cp "$(VMLINUX_H_FILE)" $@ +endif + # Consolidated Pattern rule for $(dir)/bpf_skel/ $(SKEL_TMP_OUT)/%.bpf.o: $(srctree)/tools/perf/$(dir)/bpf_skel/%.bpf.c $(LIBBPF) $(VMLINUX_H) $(OUTPUT)PERF-VERSION-FILE util/bpf_skel/perf_version.h $(call rule_mkdir) @@ -51,4 +92,10 @@ $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL) $(Q)$(BPFTOOL) gen skeleton $< > $@ .PRECIOUS: $(SKEL_TMP_OUT)/%.bpf.o + endif # CONFIG_PERF_BPF_SKEL + +clean: + $(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TOOL_TMP_OUT) $(OUTPUT)bench/bpf_skel/.tmp $(SKEL_TOOL_OUT)/*.skel.h $(OUTPUT)bench/bpf_skel/*.skel.h $(SKEL_TOOL_OUT)/vmlinux.h + +.PHONY: clean