Messages in this thread Patch in this message | | | From | Ingo Molnar <> | Subject | [PATCH 34/52] tools/perf/build: Speed up the final link | Date | Tue, 8 Oct 2013 12:11:04 +0200 |
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libtraceevent.a and liblk.a rules have always-missed dependencies, which causes python.so to be relinked at every build attempt - even if none of the affected code changes.
This slows down re-builds unnecessarily, by adding more than a second to the build time:
comet:~/tip/tools/perf> time make
...
SUBDIR /fast/mingo/tip/tools/lib/lk/ make[1]: `liblk.a' is up to date. SUBDIR /fast/mingo/tip/tools/lib/traceevent/ LINK perf GEN python/perf.so
real 0m1.701s user 0m1.338s sys 0m0.301s
Add the (trivial) dependencies to not force a re-link.
This speeds up an empty re-build enormously:
comet:~/tip/tools/perf> time make
...
real 0m0.207s user 0m0.134s sys 0m0.028s
[ This adds some coupling between the build dependencies of libtraceevent and liblk - but until those stay relatively simple this should not be an issue. ]
Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Namhyung Kim <namhyung@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/n/tip-wvmlrurufuk6mo1ovtNigguT@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- tools/perf/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/tools/perf/Makefile b/tools/perf/Makefile index 6b5452a..df76198 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -669,15 +669,19 @@ $(LIB_FILE): $(LIB_OBJS) $(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS) # libtraceevent.a -$(LIBTRACEEVENT): +TE_SOURCES = $(wildcard $(TRACE_EVENT_DIR)*.[ch]) + +$(LIBTRACEEVENT): $(TE_SOURCES) $(QUIET_SUBDIR0)$(TRACE_EVENT_DIR) $(QUIET_SUBDIR1) O=$(OUTPUT) libtraceevent.a $(LIBTRACEEVENT)-clean: $(QUIET_SUBDIR0)$(TRACE_EVENT_DIR) $(QUIET_SUBDIR1) O=$(OUTPUT) clean +LIBLK_SOURCES = $(wildcard $(LK_PATH)*.[ch]) + # if subdir is set, we've been called from above so target has been built # already -$(LIBLK): +$(LIBLK): $(LIBLK_SOURCES) ifeq ($(subdir),) $(QUIET_SUBDIR0)$(LK_DIR) $(QUIET_SUBDIR1) O=$(OUTPUT) liblk.a endif @@ -825,6 +829,6 @@ else GIT-HEAD-PHONY = endif -.PHONY: all install clean strip $(LIBTRACEEVENT) $(LIBLK) +.PHONY: all install clean strip .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell .PHONY: $(GIT-HEAD-PHONY) TAGS tags cscope .FORCE-PERF-CFLAGS -- 1.8.3.1
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