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From: Michael Opdenacker <michael.opdenacker@free-electrons.com>
To: akpm@linux-foundation.org
Cc: paulmck@linux.vnet.ibm.com, fweisbec@gmail.com,
	josh@joshtriplett.org, eparis@redhat.com,
	paul.gortmaker@windriver.com, vapier@gentoo.org,
	kyungsik.lee@lge.com, jslaby@suse.cz, dwight.engen@oracle.com,
	pefoley2@pefoley.com, linux-kernel@vger.kernel.org,
	Michael Opdenacker <michael.opdenacker@free-electrons.com>
Subject: [PATCH 1/1] init/Kconfig: improve CC_OPTIMIZE_FOR_SIZE documentation
Date: Thu, 24 Apr 2014 14:07:34 +0200	[thread overview]
Message-ID: <1398341254-4626-2-git-send-email-michael.opdenacker@free-electrons.com> (raw)
In-Reply-To: <1398341254-4626-1-git-send-email-michael.opdenacker@free-electrons.com>

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
---
 init/Kconfig | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/init/Kconfig b/init/Kconfig
index 9d3585bb2a7a..b6394a9ddc38 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1251,7 +1251,19 @@ config CC_OPTIMIZE_FOR_SIZE
 	bool "Optimize for size"
 	help
 	  Enabling this option will pass "-Os" instead of "-O2" to gcc
-	  resulting in a smaller kernel.
+	  resulting in a smaller but slower kernel.
+
+	  This option can be useful in very small systems where every
+	  byte counts.
+
+	  A smaller kernel will also be slightly faster to load and start.
+	  However, experiments have shown that such early speedups are
+	  quickly offset by the slower kernel speed. Unless you are running
+	  a very simple user space, the total boot time should be degraded
+	  by this option.
+
+	  Anyway, kernel code will be slower to execute and overall system
+  	  performance will be degraded.
 
 	  If unsure, say N.
 
-- 
1.8.3.2


  reply	other threads:[~2014-04-24 12:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-24 12:07 [PATCH 0/1] " Michael Opdenacker
2014-04-24 12:07 ` Michael Opdenacker [this message]
2014-04-24 15:06   ` [PATCH 1/1] " Josh Triplett
2014-04-24 14:55 ` [PATCH 0/1] " Josh Triplett
2014-04-24 19:34   ` Michael Opdenacker

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