I noticed that a patch I did causes the time for a clean rebuild to go up significantly, from 13 to 18 seconds on ARM defconfig, and in the worst case forcing a rebuild of every file each time.
The fix is very simple, using a ':=' assignment instead of '=' to force the cc-disable-warning call to only be evaluated once instead of every time. Signed-off-by: Arnd Bergmann <[email protected]> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 3a964fa3a787..e7d4d20deb4e 100644 --- a/Makefile +++ b/Makefile @@ -381,7 +381,7 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) ifeq ($(COMPILER),clang) -- 2.9.0
