Re: [PATCH] kmemcheck: Disable SLUB and SLAB debugging whenkmemcheck is enabled

From: Pekka Enberg
Date: Thu Feb 26 2009 - 02:17:39 EST


On Wed, 25 Feb 2009, Vegard Nossum wrote:
> > Can you rethink whether SLUB_DEBUG or SLUB_DEBUG_ON is the one we
> > really want to depend on !KMEMCHECK, and either submit a new patch or
> > convince me that this is sufficient?

On Wed, 2009-02-25 at 16:23 -0500, Christoph Lameter wrote:
> !SLUB_DEBUG_ON is the right thing to depend on.

Here's a patch to do that.

Pekka

>From bae2afd233c24d766e20e09bb92c67c0e5ea16e3 Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Date: Mon, 23 Feb 2009 11:35:13 +0200
Subject: [PATCH] kmemcheck: Disable SLUB and SLAB debugging when kmemcheck is enabled

Enabling kmemcheck in Kconfig is a painful experience. Lets make it a
tad bit easier by inverting the dependencies to SLUB and SLAB debugging.
As kmemcheck is more powerful than slab debugging, disable the latter
functionality if an user enables kmemcheck.

Cc: Vegard Nossum <vegard.nossum@xxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
---
arch/x86/Kconfig.debug | 2 +-
lib/Kconfig.debug | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index de186c5..3d1d593 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -276,7 +276,7 @@ menuconfig KMEMCHECK
bool "kmemcheck: trap use of uninitialized memory"
depends on X86
depends on !X86_USE_3DNOW
- depends on (SLUB && !SLUB_DEBUG_ON) || (SLAB && !DEBUG_SLAB)
+ depends on SLUB || SLAB
depends on !CC_OPTIMIZE_FOR_SIZE
depends on !DEBUG_PAGEALLOC
depends on !FUNCTION_TRACER
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 29044f5..e9a930c 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -262,7 +262,7 @@ config DEBUG_OBJECTS_ENABLE_DEFAULT

config DEBUG_SLAB
bool "Debug slab memory allocations"
- depends on DEBUG_KERNEL && SLAB
+ depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
help
Say Y here to have the kernel do limited verification on memory
allocation as well as poisoning memory on free to catch use of freed
@@ -274,7 +274,7 @@ config DEBUG_SLAB_LEAK

config SLUB_DEBUG_ON
bool "SLUB debugging on by default"
- depends on SLUB && SLUB_DEBUG
+ depends on SLUB && SLUB_DEBUG && !KMEMCHECK
default n
help
Boot with debugging on by default. SLUB boots by default with
--
1.5.4.3



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