Re: [2.6.25-git18 => 2.6.26-rc1-git1] Xorg crash with xf86MapVidMem error

[Ingo Molnar <mingo@elte.hu>]

* Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:

> Below is the patch to enable debug messages by a boot option 
> "debugpat".

ok, i have applied the patch with some modifications - see below.

Since we build in this code unconditionally also make the flag 
switchable from a sysctl, so that users do not have to reboot to see PAT 
debug messages ...

i have renamed PAT_PRINTK to dprintk.

	Ingo

------------>
Subject: x86: add "debugpat" boot option
From: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Mon, 5 May 2008 19:09:10 -0700

enable debug messages by a boot option "debugpat".

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/mm/pat.c |   27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

Index: linux-x86.q/arch/x86/mm/pat.c
===================================================================
--- linux-x86.q.orig/arch/x86/mm/pat.c
+++ linux-x86.q/arch/x86/mm/pat.c
@@ -38,6 +38,19 @@ static int nopat(char *str)
 }
 early_param("nopat", nopat);
 
+
+static int debug_enable;
+static int __init pat_debug_setup(char *str)
+{
+	debug_enable = 1;
+	return 0;
+}
+__setup("debugpat", pat_debug_setup);
+
+#define dprintk(fmt, arg...) \
+	do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0)
+
+
 static int pat_known_cpu(void)
 {
 	if (!pat_wc_enabled)
@@ -285,7 +298,7 @@ int reserve_memtype(u64 start, u64 end, 
 		struct memtype *saved_ptr;
 
 		if (parse->start >= end) {
-			pr_debug("New Entry\n");
+			dprintk("New Entry\n");
 			list_add(&new_entry->nd, parse->nd.prev);
 			new_entry = NULL;
 			break;
@@ -335,7 +348,7 @@ int reserve_memtype(u64 start, u64 end, 
 				break;
 			}
 
-			pr_debug("Overlap at 0x%Lx-0x%Lx\n",
+			dprintk("Overlap at 0x%Lx-0x%Lx\n",
 			       saved_ptr->start, saved_ptr->end);
 			/* No conflict. Go ahead and add this new entry */
 			list_add(&new_entry->nd, saved_ptr->nd.prev);
@@ -387,7 +400,7 @@ int reserve_memtype(u64 start, u64 end, 
 				break;
 			}
 
-			pr_debug(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n",
+			dprintk("Overlap at 0x%Lx-0x%Lx\n",
 				 saved_ptr->start, saved_ptr->end);
 			/* No conflict. Go ahead and add this new entry */
 			list_add(&new_entry->nd, &saved_ptr->nd);
@@ -409,16 +422,16 @@ int reserve_memtype(u64 start, u64 end, 
 	if (new_entry) {
 		/* No conflict. Not yet added to the list. Add to the tail */
 		list_add_tail(&new_entry->nd, &memtype_list);
-		pr_debug("New Entry\n");
+		dprintk("New Entry\n");
 	}
 
 	if (ret_type) {
-		pr_debug(
+		dprintk(
 	"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
 			start, end, cattr_name(actual_type),
 			cattr_name(req_type), cattr_name(*ret_type));
 	} else {
-		pr_debug(
+		dprintk(
 	"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
 			start, end, cattr_name(actual_type),
 			cattr_name(req_type));
@@ -459,7 +472,7 @@ int free_memtype(u64 start, u64 end)
 			current->comm, current->pid, start, end);
 	}
 
-	pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end);
+	dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
 	return err;
 }