From: Nathan Chancellor <natechancellor@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
stable@vger.kernel.org
Cc: Nick Desaulniers <ndesaulniers@google.com>,
clang-built-linux@googlegroups.com,
Matthias Kaehlcke <mka@chromium.org>,
Peter Zijlstra <peterz@infradead.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Nathan Chancellor <natechancellor@gmail.com>
Subject: [PATCH 4.19] Revert "kbuild: use -Oz instead of -Os when using clang"
Date: Tue, 23 Apr 2019 12:04:23 -0700 [thread overview]
Message-ID: <20190423190426.18720-3-natechancellor@gmail.com> (raw)
In-Reply-To: <20190423190426.18720-1-natechancellor@gmail.com>
From: Matthias Kaehlcke <mka@chromium.org>
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@infradead.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
Makefile | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 3fac08f6a11e..91e265ca0ca5 100644
--- a/Makefile
+++ b/Makefile
@@ -661,8 +661,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
-KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
+KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,)
else
ifdef CONFIG_PROFILE_ALL_BRANCHES
KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
--
2.21.0
next prev parent reply other threads:[~2019-04-23 19:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 19:04 Backport of commit a75bb4eb9e565b9f5115e2e8c07377ce32cbe69a Nathan Chancellor
2019-04-23 19:04 ` [PATCH 4.14] Revert "kbuild: use -Oz instead of -Os when using clang" Nathan Chancellor
2019-04-23 19:04 ` Nathan Chancellor [this message]
2019-04-23 19:04 ` [PATCH 4.4] " Nathan Chancellor
2019-04-23 19:04 ` [PATCH 4.9] " Nathan Chancellor
2019-04-23 19:04 ` [PATCH 5.0] " Nathan Chancellor
2019-04-23 19:35 ` Backport of commit a75bb4eb9e565b9f5115e2e8c07377ce32cbe69a Sasha Levin
2019-04-23 19:42 ` Nick Desaulniers
2019-04-23 19:45 ` Nathan Chancellor
2019-04-23 19:56 ` Matthias Kaehlcke
2019-04-23 20:03 ` Nathan Chancellor
2019-04-23 23:46 ` Sasha Levin
2019-04-24 5:58 ` Sedat Dilek
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