* [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc
@ 2026-10-13 22:16 Ian Rogers
2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi,
David Faust, Cupertino Miranda
Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers,
Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman,
Yonghong Song, linux-perf-users, bpf, linux-kernel
Currently the perf build requires clang (>= 12.0.1) to compile BPF
skeleton programs (.bpf.c -> .bpf.o). bpf-gcc (>= 14.0.0) also supports
BPF CO-RE and BTF generation and is already supported in
tools/testing/selftests/bpf/Makefile.
This series updates the perf build to support both clang and bpf-gcc:
- Patch 1 updates Makefile.config, Makefile.perf, and bpf_skel.mak to
prefer bpf-gcc when building perf with GCC (CC_NO_CLANG=1) and clang
when building with Clang/LLVM (CC_NO_CLANG=0), while respecting
explicit BPF_GCC=... or CLANG=... command-line overrides and falling
back to whichever compiler is available.
- Patch 2 adds make_bpf_skel_clang and make_bpf_skel_bpf_gcc build-test
targets to tools/perf/tests/make and verifies with
'perf check -q feature bpf_skeletons' that BPF skeleton support is
enabled (or disabled for make_no_bpf_skel) as expected.
Ian Rogers (2):
perf build: Support building BPF skeletons with bpf-gcc
perf test make: Add BPF skeleton build tests for clang and bpf-gcc
tools/perf/Makefile.config | 81 +++++++++++++++++++++++++++-------
tools/perf/Makefile.perf | 8 +++-
tools/perf/bpf_skel.mak | 36 ++++++++++-----
tools/perf/tests/make | 29 ++++++++++++
tools/scripts/Makefile.include | 1 +
5 files changed, 126 insertions(+), 29 deletions(-)
--
2.56.0.385.gd3acb90ef8-goog
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v1 1/2] perf build: Support building BPF skeletons with bpf-gcc 2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers @ 2026-10-13 22:16 ` Ian Rogers 2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers 2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2 siblings, 0 replies; 6+ messages in thread From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw) To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi, David Faust, Cupertino Miranda Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman, Yonghong Song, linux-perf-users, bpf, linux-kernel Support building perf BPF skeletons with bpf-gcc (>= 14.0.0) in addition to clang (>= 12.0.1), similar to tools/testing/selftests/bpf/Makefile. When building perf with GCC (CC_NO_CLANG=1), prefer bpf-gcc and fall back to clang if bpf-gcc is unavailable or too old. When building with Clang/LLVM (CC_NO_CLANG=0), prefer clang and fall back to bpf-gcc. Explicit command-line overrides via BPF_GCC=... or CLANG=... are respected, and setting BPF_GCC= or CLANG= to empty disables that compiler. In bpf_skel.mak, pass the bpf-gcc flags (-mcpu=v3, -fno-ident, -DBPF_NO_PRESERVE_ACCESS_INDEX, -Wno-attributes, -D__TARGET_ARCH_$(SRCARCH), and target endianness) and query system include paths from $(CC). Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/Makefile.config | 81 +++++++++++++++++++++++++++------- tools/perf/Makefile.perf | 8 +++- tools/perf/bpf_skel.mak | 36 ++++++++++----- tools/scripts/Makefile.include | 1 + 4 files changed, 97 insertions(+), 29 deletions(-) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index cafc7be79643..6aee2665b64c 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -662,27 +662,76 @@ ifeq ($(BUILD_BPF_SKEL),1) else ifeq ($(filter -DHAVE_LIBOPENSSL_SUPPORT, $(CFLAGS)),) $(warning Warning: Disabled BPF skeletons as libopenssl is required) BUILD_BPF_SKEL := 0 - else ifeq ($(call get-executable,$(CLANG)),) - $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing) - BUILD_BPF_SKEL := 0 - else - CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g') - ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) - $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1) - BUILD_BPF_SKEL := 0 - endif endif ifeq ($(BUILD_BPF_SKEL),1) - $(call feature_check,clang-bpf-co-re) - ifeq ($(feature-clang-bpf-co-re), 0) - $(warning Warning: Disabled BPF skeletons as clang is too old) + # Prefer bpf-gcc when building with gcc (CC_NO_CLANG=1) and clang when + # building with clang, unless CLANG or BPF_GCC was explicitly specified on + # the command line. Fall back to whichever compiler is available. + prefer_bpf_gcc := $(CC_NO_CLANG) + ifeq ($(origin BPF_GCC),command line) + ifneq ($(BPF_GCC),) + prefer_bpf_gcc := 1 + endif + else ifeq ($(origin CLANG),command line) + ifneq ($(CLANG),) + prefer_bpf_gcc := 0 + endif + endif + + have_bpf_gcc := 0 + have_clang_bpf := 0 + + define check_bpf_gcc + ifneq ($$(call get-executable,$$(BPF_GCC)),) + BPF_GCC_VERSION := $$(shell $$(BPF_GCC) -dumpfullversion -dumpversion 2>/dev/null) + ifneq ($$(call version-lt3,$$(BPF_GCC_VERSION),14.0.0),1) + have_bpf_gcc := 1 + endif + endif + endef + + ifeq ($(prefer_bpf_gcc),1) + $(eval $(check_bpf_gcc)) + endif + + ifeq ($(have_bpf_gcc),0) + ifneq ($(call get-executable,$(CLANG)),) + CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g') + ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) + $(call feature_check,clang-bpf-co-re) + ifeq ($(feature-clang-bpf-co-re), 1) + have_clang_bpf := 1 + endif + endif + endif + endif + + ifeq ($(prefer_bpf_gcc)$(have_clang_bpf),00) + $(eval $(check_bpf_gcc)) + endif + + ifeq ($(have_bpf_gcc),1) + $(call detected,CONFIG_PERF_BPF_SKEL_BPF_GCC) + $(call detected,CONFIG_PERF_BPF_SKEL) + CFLAGS += -DHAVE_BPF_SKEL + else ifeq ($(have_clang_bpf),1) + $(call detected,CONFIG_PERF_BPF_SKEL) + CFLAGS += -DHAVE_BPF_SKEL + else + ifeq ($(call get-executable,$(CLANG))$(call get-executable,$(BPF_GCC)),) + $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) and bpf-gcc ($(BPF_GCC)) are missing) + else ifneq ($(call get-executable,$(CLANG)),) + ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) + $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1) + else + $(warning Warning: Disabled BPF skeletons as clang is too old) + endif + else + $(warning Warning: Disabled BPF skeletons as bpf-gcc ($(BPF_GCC)) needs at least version 14.0.0) + endif BUILD_BPF_SKEL := 0 endif endif - ifeq ($(BUILD_BPF_SKEL),1) - $(call detected,CONFIG_PERF_BPF_SKEL) - CFLAGS += -DHAVE_BPF_SKEL - endif endif ifndef GEN_VMLINUX_H diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 2d9379fea267..4061a79cae54 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -37,6 +37,9 @@ include ../scripts/utilities.mak # Define EXTRA_BPF_FLAGS="--sysroot=<path>" or other custom include paths for # cross-compiling BPF skeletons # +# Define BPF_GCC to point to the bpf-gcc binary if the default `bpf-gcc' is not +# correct, or set BPF_GCC= to disable using bpf-gcc for BPF skeletons. +# # Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated # EXTLIBS. # @@ -208,6 +211,7 @@ FIND = find INSTALL = install FLEX ?= flex BISON ?= bison +BPF_GCC ?= bpf-gcc AWK = awk # include Makefile.config by default and rule out @@ -321,8 +325,8 @@ ifneq ($(force_fixdep),1) endif endif -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 CONFIG_PERF_BPF_SKEL +export srctree OUTPUT RM CC CXX RUSTC CLANG BPF_GCC LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF +export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL CONFIG_PERF_BPF_SKEL_BPF_GCC include $(srctree)/tools/build/Makefile.include diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak index f2559de39f96..7b7edf506509 100644 --- a/tools/perf/bpf_skel.mak +++ b/tools/perf/bpf_skel.mak @@ -22,21 +22,35 @@ bpf-skel-prepare: $(BPFTOOL) $(VMLINUX_H) define get_sys_includes $(shell $(1) $(2) -v -E - </dev/null 2>&1 \ | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \ -$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') +$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \ +$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}') \ +$(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) |_MIPS_SIM |_ABI(O32|N32|64) ' | awk '{printf("-D%s=%s ", $$2, $$3)}') endef -ifneq ($(CROSS_COMPILE),) -CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%)) +ifeq ($(CONFIG_PERF_BPF_SKEL_BPF_GCC),y) + BPF_CC := $(BPF_GCC) + QUIET_BPF_CC = $(QUIET_BPF_GCC) + IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \ + grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__') + BPF_OPTIONS = -Wall -mcpu=v3 -fno-ident -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes \ + -D__TARGET_ARCH_$(SRCARCH) $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) + BPF_SYS_INCLUDES = $(call get_sys_includes,$(CC),) +else + BPF_CC := $(CLANG) + QUIET_BPF_CC = $(QUIET_CLANG) + ifneq ($(CROSS_COMPILE),) + CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%)) + endif + BPF_OPTIONS = -Wall -mcpu=v3 -fno-stack-protector --target=bpf -Wno-microsoft-anon-tag + BPF_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH)) endif -CLANG_OPTIONS = -Wall -mcpu=v3 -CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH)) LIBBPF_INCLUDE := $(abspath $(or $(OUTPUT),.))/libbpf/include -BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) +BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(BPF_SYS_INCLUDES) TOOLS_UAPI_INCLUDE := -I$(srctree)/tools/include/uapi ifneq ($(WERROR),0) - CLANG_OPTIONS += -Werror + BPF_OPTIONS += -Werror endif $(BPFTOOL): @@ -83,11 +97,11 @@ 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) - $(QUIET_CLANG) - $(Q)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \ - $(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \ + $(QUIET_BPF_CC) + $(Q)$(BPF_CC) -g -O2 \ + $(BPF_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \ -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \ - -fms-extensions -Wno-microsoft-anon-tag \ + -fms-extensions \ -c $< -o $@ $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL) diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index 378387f62960..9967210b2928 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -217,6 +217,7 @@ ifneq ($(silent),1) QUIET_CC = @echo ' CC '$@; QUIET_CC_FPIC = @echo ' CC FPIC '$@; QUIET_CLANG = @echo ' CLANG '$@; + QUIET_BPF_GCC = @echo ' BPF_GCC '$@; QUIET_AR = @echo ' AR '$@; QUIET_LINK = @echo ' LINK '$@; QUIET_MKDIR = @echo ' MKDIR '$@; -- 2.56.0.385.gd3acb90ef8-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc 2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers @ 2026-10-13 22:16 ` Ian Rogers 2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2 siblings, 0 replies; 6+ messages in thread From: Ian Rogers @ 2026-10-13 22:16 UTC (permalink / raw) To: Arnaldo Carvalho de Melo, Namhyung Kim, Jose E . Marchesi, David Faust, Cupertino Miranda Cc: Peter Zijlstra, Ingo Molnar, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark, Andrii Nakryiko, Eduard Zingerman, Yonghong Song, linux-perf-users, bpf, linux-kernel Add make_bpf_skel_clang (CLANG=clang BPF_GCC=) and make_bpf_skel_bpf_gcc (BPF_GCC=bpf-gcc CLANG=) targets to tools/perf/tests/make when the corresponding compiler and BPF skeleton dependencies are available on the host. Verify with 'perf check -q feature bpf_skeletons' that BPF skeleton support is enabled for both targets and disabled for make_no_bpf_skel. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/tests/make | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/perf/tests/make b/tools/perf/tests/make index 7524de522802..4e66b93cf12c 100644 --- a/tools/perf/tests/make +++ b/tools/perf/tests/make @@ -78,6 +78,8 @@ make_extra_tests := EXTRA_TESTS=1 make_no_jevents := NO_JEVENTS=1 make_jevents_all := JEVENTS_ARCH=all make_no_bpf_skel := BUILD_BPF_SKEL=0 +make_bpf_skel_clang := CLANG=clang BPF_GCC= +make_bpf_skel_bpf_gcc := BPF_GCC=bpf-gcc CLANG= make_gen_vmlinux_h := GEN_VMLINUX_H=1 make_no_python_module := NO_PYTHON_MODULE=1 make_no_scripts := NO_PYTHON_MODULE=1 @@ -142,6 +144,20 @@ have_libllvm := $(shell printf '#include <llvm/Support/ManagedStatic.h>\n#includ $(shell $(LLVM_CONFIG) --system-libs 2>/dev/null) >/dev/null 2>&1 && echo y) endif +have_bpf_skel_deps := $(shell printf '#include <libelf.h>\n#include <zlib.h>\n#include <linux/bpf.h>\n#include <openssl/opensslv.h>\nint main(){return 0;}\n' | \ + $(CC) -x c -I$(srctree)/tools/include/uapi - -o /dev/null -lelf -lz -lcrypto >/dev/null 2>&1 && echo y) + +ifneq ($(have_bpf_skel_deps),) +ifneq ($(call has,clang),) +have_clang_bpf := $(shell printf '#if (__clang_major__ < 12) || (__clang_major__ == 12 && __clang_minor__ == 0 && __clang_patchlevel__ < 1)\n#error "old"\n#endif\n' | \ + clang -S -g --target=bpf -x c - -o /dev/null >/dev/null 2>&1 && echo y) +endif +ifneq ($(call has,bpf-gcc),) +have_bpf_gcc := $(shell printf '#if __GNUC__ < 14\n#error "old"\n#endif\n' | \ + bpf-gcc -E -x c - >/dev/null 2>&1 && echo y) +endif +endif + # $(run) contains all available tests run := make_pure # Targets 'clean all' can be run together only through top level @@ -173,6 +189,12 @@ run += make_extra_tests run += make_no_jevents run += make_jevents_all run += make_no_bpf_skel +ifneq ($(have_clang_bpf),) +run += make_bpf_skel_clang +endif +ifneq ($(have_bpf_gcc),) +run += make_bpf_skel_bpf_gcc +endif run += make_gen_vmlinux_h run += make_no_python_module run += make_no_scripts @@ -313,6 +335,13 @@ test_make_clang_nondistro := $(test_make_clang) test_make_clang_nondistro_O := $(test_make_clang_O) endif +test_make_no_bpf_skel := test -x $(PERF_O)/perf && ! $(PERF_O)/perf check -q feature bpf_skeletons +test_make_no_bpf_skel_O := test -x $$TMP_O/perf && ! $$TMP_O/perf check -q feature bpf_skeletons +test_make_bpf_skel_clang := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons +test_make_bpf_skel_clang_O := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons +test_make_bpf_skel_bpf_gcc := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons +test_make_bpf_skel_bpf_gcc_O := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons + test_make_python_perf_so_O := test -f $$TMP_O/python/perf.so test_make_perf_o_O := test -f $$TMP_O/perf.o test_make_util_map_o_O := test -f $$TMP_O/util/map.o -- 2.56.0.385.gd3acb90ef8-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc 2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers 2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers @ 2026-10-13 23:14 ` Ian Rogers 2026-10-13 23:14 ` [PATCH v2 1/2] " Ian Rogers 2026-10-13 23:14 ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers 2 siblings, 2 replies; 6+ messages in thread From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw) To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel, linux-perf-users, mingo, peterz, yonghong.song Currently the perf build requires clang (>= 12.0.1) to compile BPF skeleton programs (.bpf.c -> .bpf.o). bpf-gcc (>= 14.0.0) also supports BPF CO-RE and BTF generation and is already supported in tools/testing/selftests/bpf/Makefile. This series updates the perf build to support both clang and bpf-gcc: - Patch 1 updates Makefile.config, Makefile.perf, and bpf_skel.mak to prefer bpf-gcc when building perf with GCC (CC_NO_CLANG=1) and clang when building with Clang/LLVM (CC_NO_CLANG=0), while respecting explicit BPF_GCC=... or CLANG=... command-line overrides and falling back to whichever compiler is available. - Patch 2 adds make_bpf_skel_clang and make_bpf_skel_bpf_gcc build-test targets to tools/perf/tests/make and verifies with 'perf check -q feature bpf_skeletons' that BPF skeleton support is enabled (or disabled for make_no_bpf_skel) as expected. v2: Pass only -dumpfullversion when querying BPF_GCC_VERSION, guard against an empty version string, and fix version-ge3 / version-lt3 in tools/scripts/utilities.mak so empty or <3-component version strings do not shift awk fields and evaluate as false in version-lt3. Ian Rogers (2): perf build: Support building BPF skeletons with bpf-gcc perf test make: Add BPF skeleton build tests for clang and bpf-gcc tools/perf/Makefile.config | 83 +++++++++++++++++++++++++++------- tools/perf/Makefile.perf | 8 +++- tools/perf/bpf_skel.mak | 36 ++++++++++----- tools/perf/tests/make | 29 ++++++++++++ tools/scripts/Makefile.include | 1 + tools/scripts/utilities.mak | 4 +- 6 files changed, 130 insertions(+), 31 deletions(-) -- 2.56.0.385.gd3acb90ef8-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] perf build: Support building BPF skeletons with bpf-gcc 2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers @ 2026-10-13 23:14 ` Ian Rogers 2026-10-13 23:14 ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers 1 sibling, 0 replies; 6+ messages in thread From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw) To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel, linux-perf-users, mingo, peterz, yonghong.song Support building perf BPF skeletons with bpf-gcc (>= 14.0.0) in addition to clang (>= 12.0.1), similar to tools/testing/selftests/bpf/Makefile. When building perf with GCC (CC_NO_CLANG=1), prefer bpf-gcc and fall back to clang if bpf-gcc is unavailable or too old. When building with Clang/LLVM (CC_NO_CLANG=0), prefer clang and fall back to bpf-gcc. Explicit command-line overrides via BPF_GCC=... or CLANG=... are respected, and setting BPF_GCC= or CLANG= to empty disables that compiler. In bpf_skel.mak, pass the bpf-gcc flags (-mcpu=v3, -fno-ident, -DBPF_NO_PRESERVE_ACCESS_INDEX, -Wno-attributes, -D__TARGET_ARCH_$(SRCARCH), and target endianness) and query system include paths from $(CC). Also update version-ge3 and version-lt3 in tools/scripts/utilities.mak to split the two version arguments separately in awk so empty or fewer-than-3-component version strings do not shift fields across arguments. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/Makefile.config | 83 +++++++++++++++++++++++++++------- tools/perf/Makefile.perf | 8 +++- tools/perf/bpf_skel.mak | 36 ++++++++++----- tools/scripts/Makefile.include | 1 + tools/scripts/utilities.mak | 4 +- 5 files changed, 101 insertions(+), 31 deletions(-) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index cafc7be79643..235872e65d8f 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -662,27 +662,78 @@ ifeq ($(BUILD_BPF_SKEL),1) else ifeq ($(filter -DHAVE_LIBOPENSSL_SUPPORT, $(CFLAGS)),) $(warning Warning: Disabled BPF skeletons as libopenssl is required) BUILD_BPF_SKEL := 0 - else ifeq ($(call get-executable,$(CLANG)),) - $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing) - BUILD_BPF_SKEL := 0 - else - CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g') - ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) - $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1) - BUILD_BPF_SKEL := 0 - endif endif ifeq ($(BUILD_BPF_SKEL),1) - $(call feature_check,clang-bpf-co-re) - ifeq ($(feature-clang-bpf-co-re), 0) - $(warning Warning: Disabled BPF skeletons as clang is too old) + # Prefer bpf-gcc when building with gcc (CC_NO_CLANG=1) and clang when + # building with clang, unless CLANG or BPF_GCC was explicitly specified on + # the command line. Fall back to whichever compiler is available. + prefer_bpf_gcc := $(CC_NO_CLANG) + ifeq ($(origin BPF_GCC),command line) + ifneq ($(BPF_GCC),) + prefer_bpf_gcc := 1 + endif + else ifeq ($(origin CLANG),command line) + ifneq ($(CLANG),) + prefer_bpf_gcc := 0 + endif + endif + + have_bpf_gcc := 0 + have_clang_bpf := 0 + + define check_bpf_gcc + ifneq ($$(call get-executable,$$(BPF_GCC)),) + BPF_GCC_VERSION := $$(shell $$(BPF_GCC) -dumpfullversion 2>/dev/null) + ifneq ($$(BPF_GCC_VERSION),) + ifneq ($$(call version-lt3,$$(BPF_GCC_VERSION),14.0.0),1) + have_bpf_gcc := 1 + endif + endif + endif + endef + + ifeq ($(prefer_bpf_gcc),1) + $(eval $(check_bpf_gcc)) + endif + + ifeq ($(have_bpf_gcc),0) + ifneq ($(call get-executable,$(CLANG)),) + CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g') + ifneq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) + $(call feature_check,clang-bpf-co-re) + ifeq ($(feature-clang-bpf-co-re), 1) + have_clang_bpf := 1 + endif + endif + endif + endif + + ifeq ($(prefer_bpf_gcc)$(have_clang_bpf),00) + $(eval $(check_bpf_gcc)) + endif + + ifeq ($(have_bpf_gcc),1) + $(call detected,CONFIG_PERF_BPF_SKEL_BPF_GCC) + $(call detected,CONFIG_PERF_BPF_SKEL) + CFLAGS += -DHAVE_BPF_SKEL + else ifeq ($(have_clang_bpf),1) + $(call detected,CONFIG_PERF_BPF_SKEL) + CFLAGS += -DHAVE_BPF_SKEL + else + ifeq ($(call get-executable,$(CLANG))$(call get-executable,$(BPF_GCC)),) + $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) and bpf-gcc ($(BPF_GCC)) are missing) + else ifneq ($(call get-executable,$(CLANG)),) + ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1) + $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1) + else + $(warning Warning: Disabled BPF skeletons as clang is too old) + endif + else + $(warning Warning: Disabled BPF skeletons as bpf-gcc ($(BPF_GCC)) needs at least version 14.0.0) + endif BUILD_BPF_SKEL := 0 endif endif - ifeq ($(BUILD_BPF_SKEL),1) - $(call detected,CONFIG_PERF_BPF_SKEL) - CFLAGS += -DHAVE_BPF_SKEL - endif endif ifndef GEN_VMLINUX_H diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 2d9379fea267..4061a79cae54 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -37,6 +37,9 @@ include ../scripts/utilities.mak # Define EXTRA_BPF_FLAGS="--sysroot=<path>" or other custom include paths for # cross-compiling BPF skeletons # +# Define BPF_GCC to point to the bpf-gcc binary if the default `bpf-gcc' is not +# correct, or set BPF_GCC= to disable using bpf-gcc for BPF skeletons. +# # Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated # EXTLIBS. # @@ -208,6 +211,7 @@ FIND = find INSTALL = install FLEX ?= flex BISON ?= bison +BPF_GCC ?= bpf-gcc AWK = awk # include Makefile.config by default and rule out @@ -321,8 +325,8 @@ ifneq ($(force_fixdep),1) endif endif -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 CONFIG_PERF_BPF_SKEL +export srctree OUTPUT RM CC CXX RUSTC CLANG BPF_GCC LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF +export HOSTCC HOSTLD HOSTAR HOSTCFLAGS SHELLCHECK MYPY PYLINT CONFIG_PERF_BPF_SKEL CONFIG_PERF_BPF_SKEL_BPF_GCC include $(srctree)/tools/build/Makefile.include diff --git a/tools/perf/bpf_skel.mak b/tools/perf/bpf_skel.mak index f2559de39f96..7b7edf506509 100644 --- a/tools/perf/bpf_skel.mak +++ b/tools/perf/bpf_skel.mak @@ -22,21 +22,35 @@ bpf-skel-prepare: $(BPFTOOL) $(VMLINUX_H) define get_sys_includes $(shell $(1) $(2) -v -E - </dev/null 2>&1 \ | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \ -$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') +$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}') \ +$(shell $(1) $(2) -dM -E - </dev/null | grep '__loongarch_grlen ' | awk '{printf("-D__BITS_PER_LONG=%d", $$3)}') \ +$(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) |_MIPS_SIM |_ABI(O32|N32|64) ' | awk '{printf("-D%s=%s ", $$2, $$3)}') endef -ifneq ($(CROSS_COMPILE),) -CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%)) +ifeq ($(CONFIG_PERF_BPF_SKEL_BPF_GCC),y) + BPF_CC := $(BPF_GCC) + QUIET_BPF_CC = $(QUIET_BPF_GCC) + IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \ + grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__') + BPF_OPTIONS = -Wall -mcpu=v3 -fno-ident -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes \ + -D__TARGET_ARCH_$(SRCARCH) $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) + BPF_SYS_INCLUDES = $(call get_sys_includes,$(CC),) +else + BPF_CC := $(CLANG) + QUIET_BPF_CC = $(QUIET_CLANG) + ifneq ($(CROSS_COMPILE),) + CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%)) + endif + BPF_OPTIONS = -Wall -mcpu=v3 -fno-stack-protector --target=bpf -Wno-microsoft-anon-tag + BPF_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH)) endif -CLANG_OPTIONS = -Wall -mcpu=v3 -CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH)) LIBBPF_INCLUDE := $(abspath $(or $(OUTPUT),.))/libbpf/include -BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) +BPF_INCLUDE := -I$(SKEL_TMP_OUT)/.. -I$(SKEL_TOOL_OUT) -I$(LIBBPF_INCLUDE) $(BPF_SYS_INCLUDES) TOOLS_UAPI_INCLUDE := -I$(srctree)/tools/include/uapi ifneq ($(WERROR),0) - CLANG_OPTIONS += -Werror + BPF_OPTIONS += -Werror endif $(BPFTOOL): @@ -83,11 +97,11 @@ 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) - $(QUIET_CLANG) - $(Q)$(CLANG) -g -O2 -fno-stack-protector --target=bpf \ - $(CLANG_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \ + $(QUIET_BPF_CC) + $(Q)$(BPF_CC) -g -O2 \ + $(BPF_OPTIONS) $(EXTRA_BPF_FLAGS) $(BPF_INCLUDE) $(TOOLS_UAPI_INCLUDE) \ -include $(OUTPUT)PERF-VERSION-FILE -include util/bpf_skel/perf_version.h \ - -fms-extensions -Wno-microsoft-anon-tag \ + -fms-extensions \ -c $< -o $@ $(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o $(BPFTOOL) diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index 378387f62960..9967210b2928 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -217,6 +217,7 @@ ifneq ($(silent),1) QUIET_CC = @echo ' CC '$@; QUIET_CC_FPIC = @echo ' CC FPIC '$@; QUIET_CLANG = @echo ' CLANG '$@; + QUIET_BPF_GCC = @echo ' BPF_GCC '$@; QUIET_AR = @echo ' AR '$@; QUIET_LINK = @echo ' LINK '$@; QUIET_MKDIR = @echo ' MKDIR '$@; diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak index d69d0345cc23..746aaf6e5145 100644 --- a/tools/scripts/utilities.mak +++ b/tools/scripts/utilities.mak @@ -186,7 +186,7 @@ _gea_err = $(if $(1),$(error Please set '$(1)' appropriately)) # was to check the flex version to see if we can use compiler warnings as # errors for one of the cases flex generates code C compilers complains about. -version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) >= (10000000 * $$4 + 10000 * $$5 + $$6)) }') +version-ge3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) >= (10000000 * b[1] + 10000 * b[2] + b[3])) }') # version-lt3 # @@ -196,4 +196,4 @@ version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * # check the flex version to see if we can use compiler warnings as errors for # one of the cases flex generates code C compilers complains about. -version-lt3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) < (10000000 * $$4 + 10000 * $$5 + $$6)) }') +version-lt3 = $(shell awk -v v1="$(1)" -v v2="$(2)" 'BEGIN { split(v1, a, "."); split(v2, b, "."); printf("%d\n", (10000000 * a[1] + 10000 * a[2] + a[3]) < (10000000 * b[1] + 10000 * b[2] + b[3])) }') -- 2.56.0.385.gd3acb90ef8-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc 2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2026-10-13 23:14 ` [PATCH v2 1/2] " Ian Rogers @ 2026-10-13 23:14 ` Ian Rogers 1 sibling, 0 replies; 6+ messages in thread From: Ian Rogers @ 2026-10-13 23:14 UTC (permalink / raw) To: irogers, acme, cupertino.miranda, jose.marchesi, namhyung Cc: adrian.hunter, andrii, eddyz87, james.clark, jolsa, linux-kernel, linux-perf-users, mingo, peterz, yonghong.song Add make_bpf_skel_clang (CLANG=clang BPF_GCC=) and make_bpf_skel_bpf_gcc (BPF_GCC=bpf-gcc CLANG=) targets to tools/perf/tests/make when the corresponding compiler and BPF skeleton dependencies are available on the host. Verify with 'perf check -q feature bpf_skeletons' that BPF skeleton support is enabled for both targets and disabled for make_no_bpf_skel. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/tests/make | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/perf/tests/make b/tools/perf/tests/make index 7524de522802..4e66b93cf12c 100644 --- a/tools/perf/tests/make +++ b/tools/perf/tests/make @@ -78,6 +78,8 @@ make_extra_tests := EXTRA_TESTS=1 make_no_jevents := NO_JEVENTS=1 make_jevents_all := JEVENTS_ARCH=all make_no_bpf_skel := BUILD_BPF_SKEL=0 +make_bpf_skel_clang := CLANG=clang BPF_GCC= +make_bpf_skel_bpf_gcc := BPF_GCC=bpf-gcc CLANG= make_gen_vmlinux_h := GEN_VMLINUX_H=1 make_no_python_module := NO_PYTHON_MODULE=1 make_no_scripts := NO_PYTHON_MODULE=1 @@ -142,6 +144,20 @@ have_libllvm := $(shell printf '#include <llvm/Support/ManagedStatic.h>\n#includ $(shell $(LLVM_CONFIG) --system-libs 2>/dev/null) >/dev/null 2>&1 && echo y) endif +have_bpf_skel_deps := $(shell printf '#include <libelf.h>\n#include <zlib.h>\n#include <linux/bpf.h>\n#include <openssl/opensslv.h>\nint main(){return 0;}\n' | \ + $(CC) -x c -I$(srctree)/tools/include/uapi - -o /dev/null -lelf -lz -lcrypto >/dev/null 2>&1 && echo y) + +ifneq ($(have_bpf_skel_deps),) +ifneq ($(call has,clang),) +have_clang_bpf := $(shell printf '#if (__clang_major__ < 12) || (__clang_major__ == 12 && __clang_minor__ == 0 && __clang_patchlevel__ < 1)\n#error "old"\n#endif\n' | \ + clang -S -g --target=bpf -x c - -o /dev/null >/dev/null 2>&1 && echo y) +endif +ifneq ($(call has,bpf-gcc),) +have_bpf_gcc := $(shell printf '#if __GNUC__ < 14\n#error "old"\n#endif\n' | \ + bpf-gcc -E -x c - >/dev/null 2>&1 && echo y) +endif +endif + # $(run) contains all available tests run := make_pure # Targets 'clean all' can be run together only through top level @@ -173,6 +189,12 @@ run += make_extra_tests run += make_no_jevents run += make_jevents_all run += make_no_bpf_skel +ifneq ($(have_clang_bpf),) +run += make_bpf_skel_clang +endif +ifneq ($(have_bpf_gcc),) +run += make_bpf_skel_bpf_gcc +endif run += make_gen_vmlinux_h run += make_no_python_module run += make_no_scripts @@ -313,6 +335,13 @@ test_make_clang_nondistro := $(test_make_clang) test_make_clang_nondistro_O := $(test_make_clang_O) endif +test_make_no_bpf_skel := test -x $(PERF_O)/perf && ! $(PERF_O)/perf check -q feature bpf_skeletons +test_make_no_bpf_skel_O := test -x $$TMP_O/perf && ! $$TMP_O/perf check -q feature bpf_skeletons +test_make_bpf_skel_clang := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons +test_make_bpf_skel_clang_O := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons +test_make_bpf_skel_bpf_gcc := test -x $(PERF_O)/perf && $(PERF_O)/perf check -q feature bpf_skeletons +test_make_bpf_skel_bpf_gcc_O := test -x $$TMP_O/perf && $$TMP_O/perf check -q feature bpf_skeletons + test_make_python_perf_so_O := test -f $$TMP_O/python/perf.so test_make_perf_o_O := test -f $$TMP_O/perf.o test_make_util_map_o_O := test -f $$TMP_O/util/map.o -- 2.56.0.385.gd3acb90ef8-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-10-13 23:14 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2026-10-13 22:16 [PATCH v1 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2026-10-13 22:16 ` [PATCH v1 1/2] " Ian Rogers 2026-10-13 22:16 ` [PATCH v1 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers 2026-10-13 23:14 ` [PATCH v2 0/2] perf build: Support building BPF skeletons with bpf-gcc Ian Rogers 2026-10-13 23:14 ` [PATCH v2 1/2] " Ian Rogers 2026-10-13 23:14 ` [PATCH v2 2/2] perf test make: Add BPF skeleton build tests for clang and bpf-gcc Ian Rogers
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