perf build: Introduce FEATURES_DUMP make variable
Introducing FEATURES_DUMP make variable to provide features
detection dump file and bypass the feature detection.
The intention is to use this during build tests to skip
repeated features detection, like:
Get feature dump static build into /tmp/fd file:
$ make feature-dump FEATURE_DUMP_COPY=/tmp/fd LDFLAGS=-static
BUILD: Doing 'make -j4' parallel build
Auto-detecting system features:
... dwarf: [ OFF ]
SNIP
FEATURE-DUMP file copied into /tmp/fd
Use /tmp/fd to build perf:
$ make FEATURES_DUMP=/tmp/fd LDFLAGS=-static
$ file perf
perf: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for ...
Suggested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index f758a72..5d34815 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -77,6 +77,9 @@
# Define NO_AUXTRACE if you do not want AUX area tracing support
#
# Define NO_LIBBPF if you do not want BPF support
+#
+# Define FEATURES_DUMP to provide features detection dump file
+# and bypass the feature detection
# As per kernel Makefile, avoid funny character set dependencies
unexport LC_ALL
@@ -166,6 +169,15 @@
include config/Makefile
endif
+# The FEATURE_DUMP_EXPORT holds location of the actual
+# FEATURE_DUMP file to be used to bypass feature detection
+# (for bpf or any other subproject)
+ifeq ($(FEATURES_DUMP),)
+FEATURE_DUMP_EXPORT := $(realpath $(OUTPUT)FEATURE-DUMP)
+else
+FEATURE_DUMP_EXPORT := $(FEATURES_DUMP)
+endif
+
export prefix bindir sharedir sysconfdir DESTDIR
# sparse is architecture-neutral, which means that we need to tell it
@@ -436,7 +448,7 @@
$(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) clean >/dev/null
$(LIBBPF): fixdep FORCE
- $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(realpath $(OUTPUT)FEATURE-DUMP)
+ $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(FEATURE_DUMP_EXPORT)
$(LIBBPF)-clean:
$(call QUIET_CLEAN, libbpf)