[PATCH v3 1/4] perf: Enable libtracefs dynamic linking

From: Ian Rogers
Date: Wed Sep 22 2021 - 20:10:35 EST


Currently libtracefs isn't used by perf, but there are potential
improvements by using it as identified Steven Rostedt's e-mail:
https://lore.kernel.org/lkml/20210610154759.1ef958f0@xxxxxxxxxxxxxxxx/

This change is modelled on the dynamic libtraceevent patch by Michael
Petlan:
https://lore.kernel.org/linux-perf-users/20210428092023.4009-1-mpetlan@xxxxxxxxxx/

v3. Adds file missed in v1 and v2 spotted by Jiri Olsa.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/build/Makefile.feature | 1 +
tools/build/feature/Makefile | 4 ++++
tools/build/feature/test-libtracefs.c | 10 ++++++++++
tools/perf/Makefile.config | 9 +++++++++
tools/perf/Makefile.perf | 2 ++
5 files changed, 26 insertions(+)
create mode 100644 tools/build/feature/test-libtracefs.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 3dd2f68366f9..45a9a59828c3 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -52,6 +52,7 @@ FEATURE_TESTS_BASIC := \
libslang \
libslang-include-subdir \
libtraceevent \
+ libtracefs \
libcrypto \
libunwind \
pthread-attr-setaffinity-np \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index eff55d287db1..d024b5204ba0 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -36,6 +36,7 @@ FILES= \
test-libslang.bin \
test-libslang-include-subdir.bin \
test-libtraceevent.bin \
+ test-libtracefs.bin \
test-libcrypto.bin \
test-libunwind.bin \
test-libunwind-debug-frame.bin \
@@ -199,6 +200,9 @@ $(OUTPUT)test-libslang-include-subdir.bin:
$(OUTPUT)test-libtraceevent.bin:
$(BUILD) -ltraceevent

+$(OUTPUT)test-libtracefs.bin:
+ $(BUILD) -ltracefs
+
$(OUTPUT)test-libcrypto.bin:
$(BUILD) -lcrypto

diff --git a/tools/build/feature/test-libtracefs.c b/tools/build/feature/test-libtracefs.c
new file mode 100644
index 000000000000..8eff16c0c10b
--- /dev/null
+++ b/tools/build/feature/test-libtracefs.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <tracefs/tracefs.h>
+
+int main(void)
+{
+ struct tracefs_instance *inst = tracefs_instance_create("dummy");
+
+ tracefs_instance_destroy(inst);
+ return 0;
+}
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 446180401e26..00ec900ddbca 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -1098,6 +1098,15 @@ ifdef LIBTRACEEVENT_DYNAMIC
endif
endif

+ifdef LIBTRACEFS_DYNAMIC
+ $(call feature_check,libtracefs)
+ ifeq ($(feature-libtracefs), 1)
+ EXTLIBS += -ltracefs
+ else
+ dummy := $(error Error: No libtracefs devel library found, please install libtracefs-dev);
+ endif
+endif
+
# Among the variables below, these:
# perfexecdir
# perf_include_dir
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index e04313c4d840..7df13e74450c 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -130,6 +130,8 @@ include ../scripts/utilities.mak
#
# Define LIBTRACEEVENT_DYNAMIC to enable libtraceevent dynamic linking
#
+# Define LIBTRACEFS_DYNAMIC to enable libtracefs dynamic linking
+#

# As per kernel Makefile, avoid funny character set dependencies
unexport LC_ALL
--
2.33.0.464.g1972c5931b-goog