Make was reevaluating the shell commands in CFLAGS for every recipe because CFLAGS was defined as a recursively-expanded variable. Doing a simple expansion before putting the command output in CFLAGS prevents this reevaluation. The difference this change makes for the x86 build is stark: BEFORE: make -j 6.17s user 5.74s system 167% cpu 7.117 total make 6.52s user 5.70s system 89% cpu 13.664 total AFTER: make -j 4.03s user 1.47s system 1036% cpu 0.530 total make 3.69s user 2.16s system 92% cpu 6.310 total Signed-off-by: Peter Feiner <pfeiner@xxxxxxxxxx> --- Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 09999c6..2a2d942 100644 --- a/Makefile +++ b/Makefile @@ -42,9 +42,13 @@ cc-option = $(shell if $(CC) $(1) -S -o /dev/null -xc /dev/null \ CFLAGS += -g CFLAGS += $(autodepend-flags) -Wall -Werror -CFLAGS += $(call cc-option, -fomit-frame-pointer, "") -CFLAGS += $(call cc-option, -fno-stack-protector, "") -CFLAGS += $(call cc-option, -fno-stack-protector-all, "") + +fomit_frame_pointer := $(call cc-option, -fomit-frame-pointer, "") +fnostack_protector := $(call cc-option, -fno-stack-protector, "") +fnostack_protector_all := $(call cc-option, -fno-stack-protector-all, "") +CFLAGS += $(fomit_frame_pointer) +CFLAGS += $(fno_stack_protector) +CFLAGS += $(fno_stack_protector_all) CXXFLAGS += $(CFLAGS) -- 2.7.0.rc3.207.g0ac5344 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
