[v1,1/2] perf: support build BPF skeletons with perf
diff mbox series

Message ID 20201202093709.3374099-2-songliubraving@fb.com
State New, archived
Headers show
Series
  • Introduce perf-stat -b for BPF programs
Related show

Commit Message

Song Liu Dec. 2, 2020, 9:37 a.m. UTC
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.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/bpf/bpftool/Makefile           |  2 ++
 tools/build/Makefile.feature         |  4 ++-
 tools/perf/Makefile.config           | 10 ++++++
 tools/perf/Makefile.perf             | 46 ++++++++++++++++++++++++++--
 tools/perf/util/bpf_skel/.gitignore  |  3 ++
 tools/perf/util/bpf_skel/dummy.bpf.c | 19 ++++++++++++
 tools/scripts/Makefile.include       |  1 +
 7 files changed, 82 insertions(+), 3 deletions(-)
 create mode 100644 tools/perf/util/bpf_skel/.gitignore
 create mode 100644 tools/perf/util/bpf_skel/dummy.bpf.c

Comments

Jiri Olsa Dec. 3, 2020, 11:31 p.m. UTC | #1
On Wed, Dec 02, 2020 at 01:37:08AM -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.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/bpf/bpftool/Makefile           |  2 ++
>  tools/build/Makefile.feature         |  4 ++-
>  tools/perf/Makefile.config           | 10 ++++++
>  tools/perf/Makefile.perf             | 46 ++++++++++++++++++++++++++--
>  tools/perf/util/bpf_skel/.gitignore  |  3 ++
>  tools/perf/util/bpf_skel/dummy.bpf.c | 19 ++++++++++++
>  tools/scripts/Makefile.include       |  1 +
>  7 files changed, 82 insertions(+), 3 deletions(-)
>  create mode 100644 tools/perf/util/bpf_skel/.gitignore
>  create mode 100644 tools/perf/util/bpf_skel/dummy.bpf.c
> 
> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index f60e6ad3a1dff..a01407ec78dc5 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -120,6 +120,8 @@ endif
>  
>  BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap)
>  
> +bootstrap: $(BPFTOOL_BOOTSTRAP)
> +
>  BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o)
>  OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
>  
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 97cbfb31b7625..4eeeabbaa2947 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -99,7 +99,9 @@ FEATURE_TESTS_EXTRA :=                  \
>           clang                          \
>           libbpf                         \
>           libpfm4                        \
> -         libdebuginfod
> +         libdebuginfod			\
> +	 clang-bpf-co-re

do not use tabs in here

> +
>  
>  FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC)
>  
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index ce8516e4de34f..c8ff82b4fc1b2 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -621,6 +621,16 @@ ifndef NO_LIBBPF
>    endif
>  endif
>  
> +$(call feature_check,clang-bpf-co-re)
> +ifeq ($(feature-clang-bpf-co-re), 0)
> +  undefine BUILD_BPF_SKEL

we compile with 'make BUILD_BPF_SKEL=1' so we should fail here
with the standard 'please install..' message we use

> +endif
> +
> +ifdef BUILD_BPF_SKEL
> +    $(call detected,CONFIG_PERF_BPF_SKEL)
> +    CFLAGS += -DBUILD_BPF_SKEL
> +endif
> +
>  dwarf-post-unwind := 1
>  dwarf-post-unwind-text := BUG
>  
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 7ce3f2e8b9c74..f46f0cd012b2d 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 BUILD_BPF_SKEL to enable BPF skeletons
> +#
>  
>  # As per kernel Makefile, avoid funny character set dependencies
>  unexport LC_ALL
> @@ -178,6 +180,8 @@ LD += $(EXTRA_LDFLAGS)
>  HOSTCC  ?= gcc
>  HOSTLD  ?= ld
>  HOSTAR  ?= ar
> +CLANG ?= clang

please keep the indent with other ?= when possible

> +LLVM_STRIP ?= llvm-strip
>  
>  PKG_CONFIG = $(CROSS_COMPILE)pkg-config
>  LLVM_CONFIG ?= llvm-config
> @@ -735,7 +739,8 @@ 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 +1013,44 @@ config-clean:
>  python-clean:
>  	$(python-clean)
>  
> -clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean
> +SKEL_OUT := $(abspath util/bpf_skel)
> +SKEL_TMP_OUT := $(abspath util/bpf_skel/.tmp)

hum, actualy we use $(OUTPUT) and if it's not defined we build
directly in the tree, this should follow the same


> +SKELETONS := $(SKEL_OUT)/dummy.skel.h
> +
> +ifdef BUILD_BPF_SKEL
> +BPFTOOL := $(SKEL_TMP_OUT)/bpftool-bootstrap
> +LIBBPF_SRC := $(abspath ../lib/bpf)
> +BPF_INCLUDE := -I$(SKEL_TMP_OUT)/..
> +submake_extras := feature_display=0

there's no need for the variable, is there?
also why do we want to hide it?

thanks,
jirka
Song Liu Dec. 4, 2020, 4:13 a.m. UTC | #2
> On Dec 3, 2020, at 3:31 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Dec 02, 2020 at 01:37:08AM -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.
>> 
>> Signed-off-by: Song Liu <songliubraving@fb.com>
>> 
[...]
>> index 97cbfb31b7625..4eeeabbaa2947 100644
>> --- a/tools/build/Makefile.feature
>> +++ b/tools/build/Makefile.feature
>> @@ -99,7 +99,9 @@ FEATURE_TESTS_EXTRA :=                  \
>>          clang                          \
>>          libbpf                         \
>>          libpfm4                        \
>> -         libdebuginfod
>> +         libdebuginfod			\
>> +	 clang-bpf-co-re
> 
> do not use tabs in here

Will fix. 

> 
>> +
>> 
>> FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC)
>> 
>> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
>> index ce8516e4de34f..c8ff82b4fc1b2 100644
>> --- a/tools/perf/Makefile.config
>> +++ b/tools/perf/Makefile.config
>> @@ -621,6 +621,16 @@ ifndef NO_LIBBPF
>>   endif
>> endif
>> 
>> +$(call feature_check,clang-bpf-co-re)
>> +ifeq ($(feature-clang-bpf-co-re), 0)
>> +  undefine BUILD_BPF_SKEL
> 
> we compile with 'make BUILD_BPF_SKEL=1' so we should fail here
> with the standard 'please install..' message we use

Yeah, that makes sense. Will fix it in the next version. 

> 
>> +endif
>> +
>> +ifdef BUILD_BPF_SKEL
>> +    $(call detected,CONFIG_PERF_BPF_SKEL)
>> +    CFLAGS += -DBUILD_BPF_SKEL
>> +endif
>> +
>> dwarf-post-unwind := 1
>> dwarf-post-unwind-text := BUG
>> 
>> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
>> index 7ce3f2e8b9c74..f46f0cd012b2d 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 BUILD_BPF_SKEL to enable BPF skeletons
>> +#
>> 
>> # As per kernel Makefile, avoid funny character set dependencies
>> unexport LC_ALL
>> @@ -178,6 +180,8 @@ LD += $(EXTRA_LDFLAGS)
>> HOSTCC  ?= gcc
>> HOSTLD  ?= ld
>> HOSTAR  ?= ar
>> +CLANG ?= clang
> 
> please keep the indent with other ?= when possible

Will fix. 
> 
>> +LLVM_STRIP ?= llvm-strip
>> 
>> PKG_CONFIG = $(CROSS_COMPILE)pkg-config
>> LLVM_CONFIG ?= llvm-config
>> @@ -735,7 +739,8 @@ 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 +1013,44 @@ config-clean:
>> python-clean:
>> 	$(python-clean)
>> 
>> -clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean
>> +SKEL_OUT := $(abspath util/bpf_skel)
>> +SKEL_TMP_OUT := $(abspath util/bpf_skel/.tmp)
> 
> hum, actualy we use $(OUTPUT) and if it's not defined we build
> directly in the tree, this should follow the same

Good catch! I tested with OUTPUT in earlier version, missed it 
later on. Will fix it in the next version. 

>> +SKELETONS := $(SKEL_OUT)/dummy.skel.h
>> +
>> +ifdef BUILD_BPF_SKEL
>> +BPFTOOL := $(SKEL_TMP_OUT)/bpftool-bootstrap
>> +LIBBPF_SRC := $(abspath ../lib/bpf)
>> +BPF_INCLUDE := -I$(SKEL_TMP_OUT)/..
>> +submake_extras := feature_display=0
> 
> there's no need for the variable, is there?
> also why do we want to hide it?

I guess no need to hide it. I copied this pattern from bpftool. 
Let me remove it in v2. 

Thanks,
Song

Patch
diff mbox series

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index f60e6ad3a1dff..a01407ec78dc5 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -120,6 +120,8 @@  endif
 
 BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap)
 
+bootstrap: $(BPFTOOL_BOOTSTRAP)
+
 BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o)
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
 
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 97cbfb31b7625..4eeeabbaa2947 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -99,7 +99,9 @@  FEATURE_TESTS_EXTRA :=                  \
          clang                          \
          libbpf                         \
          libpfm4                        \
-         libdebuginfod
+         libdebuginfod			\
+	 clang-bpf-co-re
+
 
 FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC)
 
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index ce8516e4de34f..c8ff82b4fc1b2 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -621,6 +621,16 @@  ifndef NO_LIBBPF
   endif
 endif
 
+$(call feature_check,clang-bpf-co-re)
+ifeq ($(feature-clang-bpf-co-re), 0)
+  undefine BUILD_BPF_SKEL
+endif
+
+ifdef BUILD_BPF_SKEL
+    $(call detected,CONFIG_PERF_BPF_SKEL)
+    CFLAGS += -DBUILD_BPF_SKEL
+endif
+
 dwarf-post-unwind := 1
 dwarf-post-unwind-text := BUG
 
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 7ce3f2e8b9c74..f46f0cd012b2d 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 BUILD_BPF_SKEL to enable BPF skeletons
+#
 
 # As per kernel Makefile, avoid funny character set dependencies
 unexport LC_ALL
@@ -178,6 +180,8 @@  LD += $(EXTRA_LDFLAGS)
 HOSTCC  ?= gcc
 HOSTLD  ?= ld
 HOSTAR  ?= ar
+CLANG ?= clang
+LLVM_STRIP ?= llvm-strip
 
 PKG_CONFIG = $(CROSS_COMPILE)pkg-config
 LLVM_CONFIG ?= llvm-config
@@ -735,7 +739,8 @@  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 +1013,44 @@  config-clean:
 python-clean:
 	$(python-clean)
 
-clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean
+SKEL_OUT := $(abspath util/bpf_skel)
+SKEL_TMP_OUT := $(abspath util/bpf_skel/.tmp)
+SKELETONS := $(SKEL_OUT)/dummy.skel.h
+
+ifdef BUILD_BPF_SKEL
+BPFTOOL := $(SKEL_TMP_OUT)/bpftool-bootstrap
+LIBBPF_SRC := $(abspath ../lib/bpf)
+BPF_INCLUDE := -I$(SKEL_TMP_OUT)/..
+submake_extras := feature_display=0
+
+$(SKEL_TMP_OUT):
+	$(Q)$(MKDIR) -p $@
+
+$(BPFTOOL): | $(SKEL_TMP_OUT)
+	CFLAGS= $(MAKE) $(submake_extras) -C ../bpf/bpftool \
+		OUTPUT=$(SKEL_TMP_OUT)/ bootstrap
+
+$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) | $(SKEL_TMP_OUT)
+	$(call QUIET_CLANG, $@)
+	$(Q)$(CLANG) -g -O2 -target bpf $(BPF_INCLUDE) -c $(filter util/bpf_skel/%.bpf.c,$^) \
+	-o $@ && $(LLVM_STRIP) -g $@
+
+$(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o | $(BPFTOOL)
+	$(call QUIET_GENSKEL, $@)
+	$(Q)$(BPFTOOL) gen skeleton $< > $@
+
+bpf-skel: $(SKELETONS)
+
+else # BUILD_BPF_SKEL
+
+bpf-skel:
+
+endif # BUILD_BPF_SKEL
+
+bpf-skel-clean:
+	$(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TMP_OUT) $(SKELETONS)
+
+clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean 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) $(OUTPUT).config-detected
diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore
new file mode 100644
index 0000000000000..5263e9e6c5d83
--- /dev/null
+++ b/tools/perf/util/bpf_skel/.gitignore
@@ -0,0 +1,3 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+.tmp
+*.skel.h
\ No newline at end of file
diff --git a/tools/perf/util/bpf_skel/dummy.bpf.c b/tools/perf/util/bpf_skel/dummy.bpf.c
new file mode 100644
index 0000000000000..492a43a851deb
--- /dev/null
+++ b/tools/perf/util/bpf_skel/dummy.bpf.c
@@ -0,0 +1,19 @@ 
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2020 Facebook
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u64));
+} counts SEC(".maps");
+
+SEC("fentry/dummy")
+int BPF_PROG(fentry_dummy)
+{
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index a7974638561ca..ed1720dc12194 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -126,6 +126,7 @@  ifneq ($(silent),1)
 	QUIET_CLEAN    = @printf '  CLEAN    %s\n' $1;
 	QUIET_INSTALL  = @printf '  INSTALL  %s\n' $1;
 	QUIET_UNINST   = @printf '  UNINST   %s\n' $1;
+	QUIET_GENSKEL  = @printf '  GEN-SKEL   %s\n' $1;
   endif
 endif