From 9a234a2e384349f21afac8d718aa294a668ad4fa Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:34 +0900 Subject: kbuild: create directory for make cache only when necessary Currently, the existence of $(dir $(make-cache)) is always checked, and created if it is missing. We can avoid unnecessary system calls by some tricks. [1] If KBUILD_SRC is unset, we are building in the source tree. The output directory checks can be entirely skipped. [2] If at least one cache data is found, it means the cache file was included. Obviously its directory exists. Skip "mkdir -p". [3] If Makefile does not contain any call of __run-and-store, it will not create a cache file. No need to create its directory. [4] The "mkdir -p" should be only invoked by the first call of __run-and-store Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- scripts/Kbuild.include | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index be1c9d65eaf4..065324a8046f 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -99,18 +99,19 @@ cc-cross-prefix = \ # Include values from last time make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk -ifeq ($(wildcard $(dir $(make-cache))),) -$(shell mkdir -p '$(dir $(make-cache))') -endif $(make-cache): ; -include $(make-cache) +cached-data := $(filter __cached_%, $(.VARIABLES)) + # If cache exceeds 1000 lines, shrink it down to 500. -ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),) +ifneq ($(word 1000,$(cached-data)),) $(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ mv $(make-cache).tmp $(make-cache)) endif +create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1)) + # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) # # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' @@ -136,6 +137,10 @@ __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$ define __run-and-store ifeq ($(origin $(1)),undefined) $$(eval $(1) := $$(shell $$(2))) +ifeq ($(create-cache-dir),1) + $$(shell mkdir -p $(dir $(make-cache))) + $$(eval create-cache-dir :=) +endif $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) endif endef -- cgit v1.2.3