From 8fdb4a9b1ee852f9df42578621c3809c04a97fa4 Mon Sep 17 00:00:00 2001
From: Ferruh Yigit <ferruh.yigit@intel.com>
Date: Mon, 30 Jan 2017 10:21:15 +0000
Subject: [PATCH] mk: parallelize make config

make config dependency resolving was always running serial,
parallelize it for better performance.

$ time make T=x86_64-native-linuxapp-gcc config
real    0m12.633s

$ time make -j8 T=x86_64-native-linuxapp-gcc config
real    0m1.826s

When config creation done under a single make target, using a for loop,
make has no control on the action, and it needs to run as implemented in
the rule. But if for loop converted into multiple targets, make can
detect independent targets and run them parallel based on -j parameter.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
 devtools/test-build.sh          |  2 +-
 mk/internal/rte.depdirs-post.mk | 11 ++++++-----
 mk/rte.sdkdepdirs.mk            | 21 ++++++++++-----------
 mk/rte.subdir.mk                | 17 +++++++----------
 4 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/devtools/test-build.sh b/devtools/test-build.sh
index 680d79bd8f..0f131fcc67 100755
--- a/devtools/test-build.sh
+++ b/devtools/test-build.sh
@@ -146,7 +146,7 @@ config () # <directory> <target> <options>
 	fi
 	if [ ! -e $1/.config ] || $reconfig ; then
 		echo "================== Configure $1"
-		make T=$2 O=$1 config
+		make -j$J T=$2 O=$1 config
 
 		echo 'Customize configuration'
 		# Built-in options (lowercase)
diff --git a/mk/internal/rte.depdirs-post.mk b/mk/internal/rte.depdirs-post.mk
index 102a369df7..eb73ad3362 100644
--- a/mk/internal/rte.depdirs-post.mk
+++ b/mk/internal/rte.depdirs-post.mk
@@ -29,11 +29,12 @@
 #   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 #   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-.PHONY: depdirs
-depdirs:
-	@for d in $(DEPDIRS-y); do \
-		$(RTE_SDK)/buildtools/depdirs-rule.sh $(S) $$d ; \
-	done
+.PHONY: depdirs $(DEPDIRS-y)
+depdirs: $(DEPDIRS-y)
+	@echo ""
+
+$(DEPDIRS-y):
+	@$(RTE_SDK)/buildtools/depdirs-rule.sh $(S) $@
 
 .PHONY: depgraph
 depgraph:
diff --git a/mk/rte.sdkdepdirs.mk b/mk/rte.sdkdepdirs.mk
index bebaf2a297..38fd863681 100644
--- a/mk/rte.sdkdepdirs.mk
+++ b/mk/rte.sdkdepdirs.mk
@@ -36,19 +36,18 @@ ifeq (,$(wildcard $(RTE_OUTPUT)/Makefile))
   $(error "need a make config first")
 endif
 
-# use a "for" in a shell to process dependencies: we don't want this
-# task to be run in parallel.
+DEPDIR_FILES = $(addsuffix /.depdirs, $(addprefix $(BUILDDIR)/,$(ROOTDIRS-y)))
+
 .PHONY: depdirs
 depdirs: $(RTE_OUTPUT)/.depdirs
-$(RTE_OUTPUT)/.depdirs: $(RTE_OUTPUT)/.config
-	@rm -f $(RTE_OUTPUT)/.depdirs ; \
-	for d in $(ROOTDIRS-y); do \
-		if [ -f $(RTE_SRCDIR)/$$d/Makefile ]; then \
-			[ -d $(BUILDDIR)/$$d ] || mkdir -p $(BUILDDIR)/$$d ; \
-			$(MAKE) S=$$d -f $(RTE_SRCDIR)/$$d/Makefile depdirs \
-				>> $(RTE_OUTPUT)/.depdirs ; \
-		fi ; \
-	done
+$(RTE_OUTPUT)/.depdirs: $(DEPDIR_FILES)
+	@rm -f $@
+	@sort -u -o $@ $(DEPDIR_FILES)
+
+$(DEPDIR_FILES): $(RTE_OUTPUT)/.config
+	@dir=$(notdir $(@D)); \
+	[ -d $(BUILDDIR)/$$dir ] || mkdir -p $(BUILDDIR)/$$dir; \
+	$(MAKE) S=$$dir -f $(RTE_SRCDIR)/$$dir/Makefile depdirs > $@
 
 .PHONY: depgraph
 depgraph:
diff --git a/mk/rte.subdir.mk b/mk/rte.subdir.mk
index 256e64e762..5341f1feb8 100644
--- a/mk/rte.subdir.mk
+++ b/mk/rte.subdir.mk
@@ -76,7 +76,7 @@ clean: _postclean
 # include .depdirs and define rules to order priorities between build
 # of directories.
 #
-include $(RTE_OUTPUT)/.depdirs
+-include $(RTE_OUTPUT)/.depdirs
 
 define depdirs_rule
 $(1): $(sort $(patsubst $(S)/%,%,$(LOCAL_DEPDIRS-$(S)/$(1))))
@@ -84,16 +84,13 @@ endef
 
 $(foreach d,$(DIRS-y),$(eval $(call depdirs_rule,$(d))))
 
+DEPDIRS = $(wildcard $(addprefix $(S)/,$(DIRS-y)))
 
-# use a "for" in a shell to process dependencies: we don't want this
-# task to be run in parallel.
-.PHONY: depdirs
-depdirs:
-	@for d in $(DIRS-y); do \
-		if [ -f $(SRCDIR)/$$d/Makefile ]; then \
-			$(MAKE) S=$S/$$d -f $(SRCDIR)/$$d/Makefile depdirs ; \
-		fi ; \
-	done
+.PHONY: depdirs $(DEPDIRS)
+depdirs: $(DEPDIRS)
+
+$(DEPDIRS):
+	@$(MAKE) S=$@ -f $(RTE_SRCDIR)/$@/Makefile depdirs
 
 .PHONY: depgraph
 depgraph:
-- 
2.20.1