More parallelism in makefile

Andreas Schwab (schwab@issan.informatik.uni-dortmund.de)
28 Jan 1998 10:54:22 +0100

This patch improves the makefiles by making all subdirectories separate
targets that can be built in parallel. Additionally make -k works better
because the build process is not just aborted if an error occurs in one
directory, instead it continues to build the other directories. Please
tell me what you think about this.

Now if you have *very* much memory to waste you might want to try `make
-j'. :-)

--- linux-2.1.81/Makefile.~1~ Mon Jan 26 17:33:16 1998
+++ linux-2.1.81/Makefile Tue Jan 27 00:29:10 1998
@@ -227,8 +227,14 @@
$(CONFIG_SHELL) scripts/Configure arch/$(ARCH)/config.in
scripts/split-include include/linux/autoconf.h include/config

-linuxsubdirs: dummy
- set -e; for i in $(SUBDIRS); do $(MAKE) -C $$i; done
+.PHONY: linuxsubdirs
+linuxsubdirs: $(SUBDIRS)
+
+ifdef SUBDIRS
+.PHONY: $(SUBDIRS)
+$(SUBDIRS):
+ $(MAKE) -C $@
+endif

$(TOPDIR)/include/linux/version.h: include/linux/version.h
$(TOPDIR)/include/linux/compile.h: include/linux/compile.h
@@ -270,38 +276,19 @@
init/main.o: init/main.c
$(CC) $(CFLAGS) $(PROFILING) -c -o $*.o $<

-fs: dummy
- $(MAKE) linuxsubdirs SUBDIRS=fs
-
-lib: dummy
- $(MAKE) linuxsubdirs SUBDIRS=lib
-
-mm: dummy
- $(MAKE) linuxsubdirs SUBDIRS=mm
-
-ipc: dummy
- $(MAKE) linuxsubdirs SUBDIRS=ipc
-
-kernel: dummy
- $(MAKE) linuxsubdirs SUBDIRS=kernel
-
-drivers: dummy
- $(MAKE) linuxsubdirs SUBDIRS=drivers
-
-net: dummy
- $(MAKE) linuxsubdirs SUBDIRS=net
-
MODFLAGS = -DMODULE
ifdef CONFIG_MODULES
ifdef CONFIG_MODVERSIONS
MODFLAGS += -DMODVERSIONS -include $(HPATH)/linux/modversions.h
endif

-modules: include/linux/version.h
- @set -e; \
- for i in $(SUBDIRS); \
- do $(MAKE) -C $$i CFLAGS="$(CFLAGS) $(MODFLAGS)" MAKING_MODULES=1 modules; \
- done
+modules: $(addsuffix _modules,$(SUBDIRS))
+
+ifdef SUBDIRS
+.PHONY: $(addsuffix _modules,$(SUBDIRS))
+$(addsuffix _modules,$(SUBDIRS)): %_modules: include/linux/version.h
+ $(MAKE) -C $* CFLAGS="$(CFLAGS) $(MODFLAGS)" MAKING_MODULES=1 modules
+endif

modules_install:
@( \
@@ -324,7 +311,7 @@
if [ -f HAM_MODULES ]; then inst_mod HAM_MODULES net; fi; \
\
ls *.o > .allmods; \
- echo $$MODULES | tr ' ' '\n' | sort | comm -23 .allmods - > .misc; \
+ ls $$MODULES | comm -23 .allmods - > .misc; \
if [ -s .misc ]; then inst_mod .misc misc; fi; \
rm -f .misc .allmods; \
)
--- linux-2.1.81/Rules.make.~1~ Wed Jan 21 18:22:26 1998
+++ linux-2.1.81/Rules.make Tue Jan 27 00:38:07 1998
@@ -111,9 +111,14 @@
#
# A rule to make subdirectories
#
-sub_dirs: dummy
-ifdef SUB_DIRS
- set -e; for i in $(SUB_DIRS); do $(MAKE) -C $$i; done
+sub_dirs: $(SUB_DIRS)
+
+ifdef ALL_SUB_DIRS
+.PHONY: $(ALL_SUB_DIRS) $(addsuffix _modules,$(ALL_SUB_DIRS))
+$(ALL_SUB_DIRS):
+ $(MAKE) -C $@
+$(addsuffix _modules,$(ALL_SUB_DIRS)): %_modules:
+ $(MAKE) -C $* modules
endif

#
@@ -123,30 +128,23 @@
ifneq "$(strip $(ALL_MOBJS))" ""
PDWN=$(shell $(CONFIG_SHELL) $(TOPDIR)/scripts/pathdown.sh)
endif
-modules: $(ALL_MOBJS) $(MIX_OBJS) $(MI_OBJS) dummy
-ifdef MOD_SUB_DIRS
- set -e; for i in $(MOD_SUB_DIRS); do $(MAKE) -C $$i modules; done
-endif
-ifdef MOD_IN_SUB_DIRS
- set -e; for i in $(MOD_IN_SUB_DIRS); do $(MAKE) -C $$i modules; done
-endif
+.PHONY: modules
+modules: $(ALL_MOBJS) $(MIX_OBJS) $(MI_OBJS) \
+ $(addsuffix _modules,$(MOD_SUB_DIRS) $(MOD_IN_SUB_DIRS))
ifneq "$(strip $(MOD_LIST_NAME))" ""
- rm -f $$TOPDIR/modules/$(MOD_LIST_NAME)
+ rm -f $(TOPDIR)/modules/$(MOD_LIST_NAME)
ifdef MOD_SUB_DIRS
- for i in $(MOD_SUB_DIRS); do \
- echo `basename $$i`.o >> $$TOPDIR/modules/$(MOD_LIST_NAME); done
+ echo $(addsuffix .o,$(notdir $(MOD_SUB_DIRS))) >> $(TOPDIR)/modules/$(MOD_LIST_NAME)
endif
ifneq "$(strip $(ALL_MOBJS))" ""
- echo $(ALL_MOBJS) >> $$TOPDIR/modules/$(MOD_LIST_NAME)
+ echo $(ALL_MOBJS) >> $(TOPDIR)/modules/$(MOD_LIST_NAME)
endif
ifneq "$(strip $(MOD_TO_LIST))" ""
- echo $(MOD_TO_LIST) >> $$TOPDIR/modules/$(MOD_LIST_NAME)
+ echo $(MOD_TO_LIST) >> $(TOPDIR)/modules/$(MOD_LIST_NAME)
endif
endif
ifneq "$(strip $(ALL_MOBJS))" ""
- echo $(PDWN)
- cd $$TOPDIR/modules; for i in $(ALL_MOBJS); do \
- ln -sf ../$(PDWN)/$$i $$i; done
+ ln -sf $(addprefix ../$(PDWN),$(ALL_MOBJS)) $(TOPDIR)/modules
endif

#
@@ -212,7 +210,7 @@
endif # CONFIG_MODVERSIONS

ifneq "$(strip $(SYMTAB_OBJS))" ""
-$(SYMTAB_OBJS): $(TOPDIR)/include/linux/modversions.h $(SYMTAB_OBJS:.o=.c)
+$(SYMTAB_OBJS): $(TOPDIR)/include/linux/modversions.h
$(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -DEXPORT_SYMTAB -c $(@:.o=.c)
@ ( \
echo 'ifeq ($(strip $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -DEXPORT_SYMTAB),$$(strip $$(CFLAGS) $$(EXTRA_CFLAGS) $$(CFLAGS_$@) -DEXPORT_SYMTAB))' ; \

-- 
Andreas Schwab                                      "And now for something
schwab@issan.informatik.uni-dortmund.de              completely different"
schwab@gnu.org