From: Arnd Bergmann <arnd@arndb.de>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <mmarek@suse.com>, Arnd Bergmann <arnd@arndb.de>,
linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] kbuild: fix compile time regression
Date: Thu, 16 Mar 2017 15:31:09 +0100 [thread overview]
Message-ID: <20170316143124.1513546-1-arnd@arndb.de> (raw)
In-Reply-To: <CAK8P3a0792yTULUhMi2Tj0KzA_nRznnZ2-vVa9Ga_8pNe5UbNg@mail.gmail.com>
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 <arnd@arndb.de>
---
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
next prev parent reply other threads:[~2017-03-16 15:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-13 10:40 cc1: error: unrecognized command line option "-Wno-maybe-uninitialized" kbuild test robot
2017-01-13 15:40 ` [PATCH] Kbuild: use cc-disable-warning consistently for maybe-uninitialized Arnd Bergmann
2017-01-27 16:03 ` Arnd Bergmann
2017-03-14 16:17 ` Masahiro Yamada
2017-03-14 20:52 ` Arnd Bergmann
2017-03-16 14:23 ` Arnd Bergmann
2017-03-16 14:31 ` Arnd Bergmann [this message]
2017-03-16 17:41 ` [PATCH] kbuild: fix compile time regression Masahiro Yamada
2017-03-16 17:38 ` [PATCH] Kbuild: use cc-disable-warning consistently for maybe-uninitialized Masahiro Yamada
2017-03-16 17:35 ` Masahiro Yamada
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