| Message ID | 20191126121253.28253-1-jolsa@kernel.org |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | perf tools: Allow to link with libbpf dynamicaly | expand |
Em Tue, Nov 26, 2019 at 01:12:53PM +0100, Jiri Olsa escreveu: > Currently we support only static linking with kernel's > libbpf (tools/lib/bpf). This patch adds libbpf package > detection and support to link perf with it dynamically. > > The libbpf package status is displayed with: > > $ make VF=1 > Auto-detecting system features: > ... > ... libbpf: [ on ] > > It's not checked by default, because it's quite new. > Once it's on most distros we can switch it on. > > For the same reason it's not added to the test-all check. > > Perf does not need advanced version of libbpf, so we can > check just for the base bpf_object__open function. > > Adding new compile variable to detect libbpf package and > link bpf dynamically: > > $ make LIBBPF_DYNAMIC=1 > ... > LINK perf > $ ldd perf | grep bpf > libbpf.so.0 => /lib64/libbpf.so.0 (0x00007f46818bc000) > > If libbpf is not installed, build stops with: > > Makefile.config:486: *** Error: No libbpf devel library found,\ > please install libbpf-devel. Stop. Thanks, tested with how I build it: $ make LIBBPF_DYNAMIC=1 -C tools/perf O=/tmp/build/perf make: Entering directory '/home/acme/git/perf/tools/perf' BUILD: Doing 'make -j8' parallel build Makefile.config:493: *** Error: No libbpf devel library found, please install libbpf-devel. Stop. make[1]: *** [Makefile.perf:225: sub-make] Error 2 make: *** [Makefile:70: all] Error 2 make: Leaving directory '/home/acme/git/perf/tools/perf' $ works as well as advertised, applied. - Arnaldo
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 8a19753cc26a..574c2e0b9d20 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -96,7 +96,8 @@ FEATURE_TESTS_EXTRA := \ cxx \ llvm \ llvm-version \ - clang + clang \ + libbpf FEATURE_TESTS ?= $(FEATURE_TESTS_BASIC) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 8499385365c0..f30a89046aa3 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -53,6 +53,7 @@ FILES= \ test-zlib.bin \ test-lzma.bin \ test-bpf.bin \ + test-libbpf.bin \ test-get_cpuid.bin \ test-sdt.bin \ test-cxx.bin \ @@ -270,6 +271,9 @@ $(OUTPUT)test-get_cpuid.bin: $(OUTPUT)test-bpf.bin: $(BUILD) +$(OUTPUT)test-libbpf.bin: + $(BUILD) -lbpf + $(OUTPUT)test-sdt.bin: $(BUILD) diff --git a/tools/build/feature/test-libbpf.c b/tools/build/feature/test-libbpf.c new file mode 100644 index 000000000000..a508756cf4cc --- /dev/null +++ b/tools/build/feature/test-libbpf.c @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <bpf/libbpf.h> + +int main(void) +{ + return bpf_object__open("test") ? 0 : -1; +} diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 1783427da9b0..c90f4146e5a2 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -483,6 +483,16 @@ ifndef NO_LIBELF ifeq ($(feature-bpf), 1) CFLAGS += -DHAVE_LIBBPF_SUPPORT $(call detected,CONFIG_LIBBPF) + + # detecting libbpf without LIBBPF_DYNAMIC, so make VF=1 shows libbpf detection status + $(call feature_check,libbpf) + ifdef LIBBPF_DYNAMIC + ifeq ($(feature-libbpf), 1) + EXTLIBS += -lbpf + else + dummy := $(error Error: No libbpf devel library found, please install libbpf-devel); + endif + endif endif ifndef NO_DWARF diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 1cd294468a1f..eae5d5e95952 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -116,6 +116,8 @@ include ../scripts/utilities.mak # # Define TCMALLOC to enable tcmalloc heap profiling. # +# Define LIBBPF_DYNAMIC to enable libbpf dynamic linking. +# # As per kernel Makefile, avoid funny character set dependencies unexport LC_ALL @@ -360,7 +362,9 @@ export PERL_PATH PERFLIBS = $(LIBAPI) $(LIBTRACEEVENT) $(LIBSUBCMD) $(LIBPERF) ifndef NO_LIBBPF - PERFLIBS += $(LIBBPF) + ifndef LIBBPF_DYNAMIC + PERFLIBS += $(LIBBPF) + endif endif # We choose to avoid "if .. else if .. else .. endif endif"
Currently we support only static linking with kernel's libbpf (tools/lib/bpf). This patch adds libbpf package detection and support to link perf with it dynamically. The libbpf package status is displayed with: $ make VF=1 Auto-detecting system features: ... ... libbpf: [ on ] It's not checked by default, because it's quite new. Once it's on most distros we can switch it on. For the same reason it's not added to the test-all check. Perf does not need advanced version of libbpf, so we can check just for the base bpf_object__open function. Adding new compile variable to detect libbpf package and link bpf dynamically: $ make LIBBPF_DYNAMIC=1 ... LINK perf $ ldd perf | grep bpf libbpf.so.0 => /lib64/libbpf.so.0 (0x00007f46818bc000) If libbpf is not installed, build stops with: Makefile.config:486: *** Error: No libbpf devel library found,\ please install libbpf-devel. Stop. Link: http://lkml.kernel.org/n/tip-kjdr6k37nuoiwbl0yltla1nh@git.kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/build/Makefile.feature | 3 ++- tools/build/feature/Makefile | 4 ++++ tools/build/feature/test-libbpf.c | 7 +++++++ tools/perf/Makefile.config | 10 ++++++++++ tools/perf/Makefile.perf | 6 +++++- 5 files changed, 28 insertions(+), 2 deletions(-) create mode 100644 tools/build/feature/test-libbpf.c