On Thu, 2011-08-11 at 13:30 +0200, Tim Sander wrote:

The error does not occur  when configured with 
CONFIG_PREEMPT_RT_FULL=y
but with 
CONFIG_PREEMPT_RTB=y.
The same error also happens with
CONFIG_PREEMPT_LL=y. (A log is appended after the other log just
search for CONFIG_PREEMPT_LL 
for starting point). 

Does the below (on top of -rt8) cure things for you? Shouldn't make a
difference for PREEMPT_LL though, so maybe there's something else busted
as well. But from what I can tell PREEMPT_BASE should be fine with such
things disabling preemption..



---
Index: linux-2.6/include/linux/uaccess.h
===================================================================

--- linux-2.6.orig/include/linux/uaccess.h
+++ linux-2.6/include/linux/uaccess.h

@@ -22,7 +22,7 @@ static inline void raw_pagefault_enable(
 	preempt_check_resched();
 }
 
-#ifndef CONFIG_PREEMPT_RT_FULL
+#ifndef CONFIG_PREEMPT_RT_BASE
 static inline void pagefault_disable(void)
 {
 	raw_pagefault_disable();

Index: linux-2.6/mm/memory.c
===================================================================

--- linux-2.6.orig/mm/memory.c
+++ linux-2.6/mm/memory.c

@@ -3438,7 +3438,7 @@ int handle_pte_fault(struct mm_struct *m
 	return 0;
 }
 
-#ifdef CONFIG_PREEMPT_RT_FULL
+#ifdef CONFIG_PREEMPT_RT_BASE
 void pagefault_disable(void)
 {
 	migrate_disable();