From: Arjan van de Ven <arjan@infradead.org>
To: mingo@elte.hu
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] x86: Don't use the strict copy checks when branch profiling is in use
Date: Tue, 6 Oct 2009 07:04:52 -0700 [thread overview]
Message-ID: <20091006070452.5e1fc119@infradead.org> (raw)
>From 3719b55e3091ad2cf8c2cfc358223c2b749ff3fd Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Tue, 6 Oct 2009 07:02:10 -0700
Subject: [PATCH] x86: Don't use the strict copy checks when branch profiling is in use
The branch profiling creates very complex code for each if statement,
to the point that gcc has trouble even analyzing something as simple
as
if (count > 5)
count = 5;
This then means that causing an error on code that gcc cannot analyze
for copy_from_user() and co is not very productive.
This patch excludes the strict copy checks in the case of branch
profiling being enabled.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
arch/x86/Kconfig.debug | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 1bd2e36..fb772b6 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -289,7 +289,7 @@ config OPTIMIZE_INLINING
config DEBUG_STRICT_USER_COPY_CHECKS
bool "Strict copy size checks"
- depends on DEBUG_KERNEL
+ depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
---help---
Enabling this option turns a certain set of sanity checks for user
copy operations into compile time failures.
--
1.6.2.5
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next reply other threads:[~2009-10-06 14:05 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-06 14:04 Arjan van de Ven [this message]
2009-10-12 20:43 ` [tip:x86/asm] " tip-bot for Arjan van de Ven
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20091006070452.5e1fc119@infradead.org \
--to=arjan@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®