Messages in this thread |  | | Date | Mon, 23 Nov 2020 00:35:21 +0100 | From | Jiri Olsa <> | Subject | Re: [RFC 1/2] perf: support build BPF skeletons with perf |
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On Wed, Nov 18, 2020 at 08:50:45PM -0800, Song Liu wrote: > BPF programs are useful in perf to profile BPF programs. BPF skeleton is > by far the easiest way to write BPF tools. Enable building BPF skeletons > in util/bpf_skel. A dummy bpf skeleton is added. More bpf skeletons will > be added for different use cases.
I was just in a place adding bpf program to perf as well, so this will save me some time ;-) thanks!
jirka
> > Signed-off-by: Song Liu <songliubraving@fb.com> > --- > tools/build/Makefile.feature | 3 +- > tools/perf/Makefile.config | 7 +++ > tools/perf/Makefile.perf | 15 +++++- > tools/perf/util/bpf_skel/.gitignore | 3 ++ > tools/perf/util/bpf_skel/Makefile | 71 ++++++++++++++++++++++++++++ > tools/perf/util/bpf_skel/dummy.bpf.c | 19 ++++++++ > 6 files changed, 115 insertions(+), 3 deletions(-) > create mode 100644 tools/perf/util/bpf_skel/.gitignore > create mode 100644 tools/perf/util/bpf_skel/Makefile > create mode 100644 tools/perf/util/bpf_skel/dummy.bpf.c > > diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature > index 97cbfb31b7625..95a58b5564218 100644 > --- a/tools/build/Makefile.feature > +++ b/tools/build/Makefile.feature > @@ -70,7 +70,8 @@ FEATURE_TESTS_BASIC := \ > libaio \ > libzstd \ > disassembler-four-args \ > - file-handle > + file-handle \ > + clang-bpf-co-re > > # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list > # of all feature tests > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config > index ce8516e4de34f..1c2c0f4badd85 100644 > --- a/tools/perf/Makefile.config > +++ b/tools/perf/Makefile.config > @@ -619,6 +619,13 @@ ifndef NO_LIBBPF > msg := $(warning BPF API too old. Please install recent kernel headers. BPF support in 'perf record' is disabled.) > NO_LIBBPF := 1 > endif > + > + ifndef NO_BPF_SKEL > + ifeq ($(feature-clang-bpf-co-re), 1) > + BUILD_BPF_SKEL := 1 > + $(call detected,CONFIG_PERF_BPF_SKEL) > + endif > + endif > endif > > dwarf-post-unwind := 1 > diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf > index 7ce3f2e8b9c74..9a9fc71e2ffa4 100644 > --- a/tools/perf/Makefile.perf > +++ b/tools/perf/Makefile.perf > @@ -126,6 +126,8 @@ include ../scripts/utilities.mak > # > # Define NO_LIBDEBUGINFOD if you do not want support debuginfod > # > +# Define NO_BPF_SKEL if you do not want build BPF skeletons > +# > > # As per kernel Makefile, avoid funny character set dependencies > unexport LC_ALL > @@ -735,7 +737,8 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioc > $(x86_arch_prctl_code_array) \ > $(rename_flags_array) \ > $(arch_errno_name_array) \ > - $(sync_file_range_arrays) > + $(sync_file_range_arrays) \ > + bpf-skel > > $(OUTPUT)%.o: %.c prepare FORCE > $(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(build-dir) $@ > @@ -1008,7 +1011,15 @@ config-clean: > python-clean: > $(python-clean) > > +ifdef BUILD_BPF_SKEL > +bpf-skel: > + $(Q)$(MAKE) -C util/bpf_skel > +else > +bpf-skel: > +endif > + > clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean > + $(call descend,util/bpf_skel,clean) > $(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(LANG_BINDINGS) > $(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete > $(Q)$(RM) $(OUTPUT).config-detected > @@ -1071,7 +1082,7 @@ endif > > FORCE: > > -.PHONY: all install clean config-clean strip install-gtk > +.PHONY: all install clean config-clean strip install-gtk bpf-skel > .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell > .PHONY: $(GIT-HEAD-PHONY) TAGS tags cscope FORCE prepare > .PHONY: libtraceevent_plugins archheaders > diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore > new file mode 100644 > index 0000000000000..5263e9e6c5d83 > --- /dev/null > +++ b/tools/perf/util/bpf_skel/.gitignore > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +.tmp > +*.skel.h > \ No newline at end of file > diff --git a/tools/perf/util/bpf_skel/Makefile b/tools/perf/util/bpf_skel/Makefile > new file mode 100644 > index 0000000000000..853bece088f4b > --- /dev/null > +++ b/tools/perf/util/bpf_skel/Makefile > @@ -0,0 +1,71 @@ > +# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) > +SKEL_OUTPUT := $(abspath .) > +TMP_OUTPUT := $(abspath .tmp) > +CLANG ?= clang > +LLC ?= llc > +LLVM_STRIP ?= llvm-strip > +DEFAULT_BPFTOOL := $(TMP_OUTPUT)/sbin/bpftool > +BPFTOOL ?= $(DEFAULT_BPFTOOL) > +LIBBPF_SRC := $(abspath ../../../lib/bpf) > +BPFOBJ := $(TMP_OUTPUT)/libbpf.a > +BPF_INCLUDE := $(TMP_OUTPUT) > +INCLUDES := -I$(TMP_OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../../lib) \ > + -I$(abspath ../../../include/uapi) > +CFLAGS := -g -Wall > + > +# Try to detect best kernel BTF source > +KERNEL_REL := $(shell uname -r) > +VMLINUX_BTF_PATHS := /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL) > +VMLINUX_BTF_PATH := $(or $(VMLINUX_BTF),$(firstword \ > + $(wildcard $(VMLINUX_BTF_PATHS)))) > +ifeq ($(V),1) > +Q = > +msg = > +else > +Q = @ > +msg = @printf ' %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))"; > +MAKEFLAGS += --no-print-directory > +submake_extras := feature_display=0 > +endif > + > +SKELETONS := $(SKEL_OUTPUT)/dummy.skel.h > + > +.DELETE_ON_ERROR: > + > +.PHONY: all clean > +all: $(SKELETONS) > + > +clean: > + $(call msg,CLEAN,bpf_skel) > + $(Q)rm -rf $(TMP_OUTPUT) $(SKELETONS) > + > +$(SKEL_OUTPUT)/%.skel.h: $(TMP_OUTPUT)/%.bpf.o | $(BPFTOOL) > + $(call msg,GEN-SKEL,$@) > + $(Q)$(BPFTOOL) gen skeleton $< > $@ > + > +$(TMP_OUTPUT)/%.bpf.o: %.bpf.c $(TMP_OUTPUT)/vmlinux.h $(BPFOBJ) | $(TMP_OUTPUT) > + $(call msg,BPF,$@) > + $(Q)$(CLANG) -g -O2 -target bpf $(INCLUDES) \ > + -c $(filter %.c,$^) -o $@ && \ > + $(LLVM_STRIP) -g $@ > + > +$(TMP_OUTPUT): > + $(call msg,MKDIR,$@) > + $(Q)mkdir -p $(TMP_OUTPUT) > + > +$(TMP_OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(TMP_OUTPUT) $(BPFTOOL) > + $(call msg,GEN,$@) > + $(Q)if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \ > + echo "Couldn't find kernel BTF; set VMLINUX_BTF to" \ > + "specify its location." >&2; \ > + exit 1;\ > + fi > + $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@ > + > +$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(TMP_OUTPUT) > + $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \ > + OUTPUT=$(abspath $(dir $@))/ $(abspath $@) > + > +$(DEFAULT_BPFTOOL): | $(TMP_OUTPUT) > + $(Q)$(MAKE) $(submake_extras) -C ../../../bpf/bpftool \ > + prefix= OUTPUT=$(TMP_OUTPUT)/ DESTDIR=$(TMP_OUTPUT) install > diff --git a/tools/perf/util/bpf_skel/dummy.bpf.c b/tools/perf/util/bpf_skel/dummy.bpf.c > new file mode 100644 > index 0000000000000..085fcee1f52cf > --- /dev/null > +++ b/tools/perf/util/bpf_skel/dummy.bpf.c > @@ -0,0 +1,19 @@ > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +// Copyright (c) 2020 Facebook > +#include "vmlinux.h" > +#include <bpf/bpf_helpers.h> > +#include <bpf/bpf_tracing.h> > + > +struct { > + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); > + __uint(key_size, sizeof(u32)); > + __uint(value_size, sizeof(u64)); > +} counts SEC(".maps"); > + > +SEC("fentry/dummy") > +int BPF_PROG(fentry_dummy) > +{ > + return 0; > +} > + > +char LICENSE[] SEC("license") = "Dual BSD/GPL"; > -- > 2.24.1 >
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