* [PATCH 15/22] perf tools: Allow to link with libbpf dynamicaly
[not found] <20191128134027.23726-1-acme@kernel.org>
@ 2019-11-28 13:40 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; only message in thread
From: Arnaldo Carvalho de Melo @ 2019-11-28 13:40 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner
Cc: Jiri Olsa, Namhyung Kim, Clark Williams, linux-kernel,
linux-perf-users, Arnaldo Carvalho de Melo,
Toke Høiland-Jørgensen, Alexander Shishkin,
Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann,
Jesper Dangaard Brouer, Martin KaFai Lau, Michael Petlan,
Peter Zijlstra, Song Liu, Yonghong Song, bpf, netdev
From: Jiri Olsa <jolsa@kernel.org>
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.
Committer testing:
$ 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'
$
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191126121253.28253-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
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
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"
--
2.21.0
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