[PATCH] Disable slow duplicate object tracking in ACPI_DEBUG

[Andi Kleen <ak-l3A5Bk7waGM@public.gmane.org>]

The current SUSE 10.0 beta has CONFIG_ACPI_DEBUG enabled. That lead
to severe slowdowns on several machines. One issue was the different
default for ec_burst_mode. Another one was that the object tracking
would always walk the full list of all objects, which lead to kacpid
needing up to 25% of the total CPU time.

This patch disables the slow list walking. It could be probably
replaced with a hash or similar too, but I don't think the duplicate
object tracking is too useful anaywys so I just disabled it.

-Andi

From: ak-l3A5Bk7waGM@public.gmane.org
Subject: Disable linear search in ACPI debugging
Suse-bugzilla: 102565

Looking through all the memory objects all the time is just too slow.
Don't do it.


Signed-off-by: Andi Kleen <ak-l3A5Bk7waGM@public.gmane.org>

Index: linux-2.6.13rc5/drivers/acpi/utilities/utalloc.c
===================================================================
--- linux-2.6.13rc5.orig/drivers/acpi/utilities/utalloc.c
+++ linux-2.6.13rc5/drivers/acpi/utilities/utalloc.c
@@ -674,6 +674,9 @@ acpi_ut_find_allocation (
 {
 	struct acpi_debug_mem_block     *element;
 
+	/* too slow to be usable */
+	return NULL;
+
 
 	ACPI_FUNCTION_ENTRY ();
 


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