[PATCH 4.4 164/168] Revert "kbuild: use -Oz instead of -Os when using clang"

From: Greg Kroah-Hartman
Date: Wed Apr 24 2019 - 13:23:28 EST


commit a75bb4eb9e565b9f5115e2e8c07377ce32cbe69a upstream.

The clang option -Oz enables *aggressive* optimization for size,
which doesn't necessarily result in smaller images, but can have
negative impact on performance. Switch back to the less aggressive
-Os.

This reverts commit 6748cb3c299de1ffbe56733647b01dbcc398c419.

Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 7bf3fb717921..cc621fbe6c62 100644
--- a/Makefile
+++ b/Makefile
@@ -639,7 +639,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
KBUILD_CFLAGS += $(call cc-disable-warning, attribute-alias)

ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
+KBUILD_CFLAGS += -Os
else
ifdef CONFIG_PROFILE_ALL_BRANCHES
KBUILD_CFLAGS += -O2
--
2.19.1