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authorMasahiro Yamada <masahiroy@kernel.org>2020-06-01 14:57:00 +0900
committerMasahiro Yamada <masahiroy@kernel.org>2020-06-03 13:22:17 +0900
commitb2c88554912267483baf8b4f5ae0a1bff529f6a3 (patch)
treeaf11987104ffb472eb6fa279204bcc2eb18d71ed /scripts
parentf0d50ca045e44dd7b423c2ae69f6a598f07d93e3 (diff)
downloadlinux-b2c88554912267483baf8b4f5ae0a1bff529f6a3.tar.bz2
kbuild: update modules.order only when contained modules are updated
Make modules.order depend on $(obj-m), and use if_changed to build it. This will avoid unneeded update of modules.order, which will be useful to optimize the modpost stage. Currently, the second pass of modpost is always invoked. By checking the timestamp of modules.order, we can avoid the unneeded modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'scripts')
-rw-r--r--scripts/Makefile.build21
-rw-r--r--scripts/Makefile.lib27
2 files changed, 27 insertions, 21 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a1f09bec8c70..2e8810b7e5ed 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -71,7 +71,7 @@ endif
# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
-subdir-modorder := $(sort $(filter %/modules.order, $(modorder)))
+subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
targets-for-builtin := $(extra-y)
@@ -83,8 +83,7 @@ ifdef need-builtin
targets-for-builtin += $(obj)/built-in.a
endif
-targets-for-modules := $(obj-m)
-targets-for-modules += $(patsubst %.o, %.mod, $(obj-m))
+targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
ifdef need-modorder
targets-for-modules += $(obj)/modules.order
@@ -361,8 +360,9 @@ endif
$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
$(call if_changed_rule,as_o_S)
-targets += $(filter-out $(subdir-builtin), $(real-obj-y)) $(real-obj-m) $(lib-y)
-targets += $(always-y) $(MAKECMDGOALS)
+targets += $(filter-out $(subdir-builtin), $(real-obj-y))
+targets += $(filter-out $(subdir-modorder), $(real-obj-m))
+targets += $(lib-y) $(always-y) $(MAKECMDGOALS)
# Linker scripts preprocessor (.lds.S -> .lds)
# ---------------------------------------------------------------------------
@@ -404,11 +404,16 @@ $(obj)/built-in.a: $(real-obj-y) FORCE
#
# Create commands to either record .ko file or cat modules.order from
# a subdirectory
-$(obj)/modules.order: $(subdir-modorder) FORCE
- $(Q){ $(foreach m, $(modorder), \
- $(if $(filter $^, $m), cat $m, echo $m);) :; } \
+# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
+# modules.order unless contained modules are updated.
+
+cmd_modules_order = { $(foreach m, $(real-prereqs), \
+ $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
| $(AWK) '!x[$$0]++' - > $@
+$(obj)/modules.order: $(obj-m) FORCE
+ $(call if_changed,modules_order)
+
#
# Rule to compile a set of .o files into one .a file (with symbol table)
#
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 748e44d5a1e3..e598b07e6de4 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -32,27 +32,29 @@ obj-m := $(filter-out $(obj-y),$(obj-m))
# Filter out objects already built-in
lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
-# Determine modorder.
-# Unfortunately, we don't have information about ordering between -y
-# and -m subdirs. Just put -y's first.
-ifdef need-modorder
-modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
-endif
-
# Subdirectories we need to descend into
subdir-ym := $(sort $(subdir-y) $(subdir-m) \
$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
-# Handle objects in subdirs
-# ---------------------------------------------------------------------------
-# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.a
-# o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
+# Handle objects in subdirs:
+# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
+# foo/modules.order
+# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
+#
+# Generate modules.order to determine modorder. Unfortunately, we don't have
+# information about ordering between -y and -m subdirs. Just put -y's first.
+
+ifdef need-modorder
+obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
+else
+obj-m := $(filter-out %/, $(obj-m))
+endif
+
ifdef need-builtin
obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
else
obj-y := $(filter-out %/, $(obj-y))
endif
-obj-m := $(filter-out %/, $(obj-m))
# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m))))
@@ -81,7 +83,6 @@ endif
extra-y := $(addprefix $(obj)/,$(extra-y))
always-y := $(addprefix $(obj)/,$(always-y))
targets := $(addprefix $(obj)/,$(targets))
-modorder := $(addprefix $(obj)/,$(modorder))
obj-m := $(addprefix $(obj)/,$(obj-m))
lib-y := $(addprefix $(obj)/,$(lib-y))
real-obj-y := $(addprefix $(obj)/,$(real-obj-y))