From c9404c6650d8f58ce8cf98d4c5581fc5c9e37faf Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 1 Oct 2013 17:17:22 +0200 Subject: [PATCH] tools/perf/build: Speed up the final link 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 Cc: Peter Zijlstra Cc: Namhyung Kim Cc: David Ahern Cc: Jiri Olsa Link: http://lkml.kernel.org/n/tip-wvmlrurufuk6mo1ovtNigguT@git.kernel.org Signed-off-by: Ingo Molnar --- tools/perf/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/perf/Makefile b/tools/perf/Makefile index 6b5452a120af..df76198d45d4 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