Re: 2.6.24-rc8-mm1

Venki Pallipadi
2008-01-17T23:34:12Z

On Thu, Jan 17, 2008 at 11:40:32AM -0800, Andrew Morton wrote:
> On Thu, 17 Jan 2008 11:22:19 -0800 "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> wrote:
>
> >
> > The problem is
> > >> modprobe:2584 conflicting cache attribute 50000000-50001000
> > >> uncached<->default
> >
> > Some address range here is being mapped with conflicting types.
> > Somewhere the range was mapped with default (write-back). Later
> > pci_iomap() is mapping that region as uncacheable which is basically
> > aliasing. PAT code detects the aliasing and fails the second uncacheable
> > request which leads in the failure.
>
> It sounds to me like you need considerably more runtime debugging and
> reporting support in that code. Ensure that it generates enough output
> both during regular operation and during failures for you to be able to
> diagnose things in a single iteration.
>
> We can always take it out later.
>
>

Patch below makes the interesting printks from PAT non DEBUG.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

Index: linux-2.6.git/arch/x86/mm/ioremap.c
===================================================================
--- linux-2.6.git.orig/arch/x86/mm/ioremap.c 2008-01-17 03:18:59.000000000 -0800
+++ linux-2.6.git/arch/x86/mm/ioremap.c 2008-01-17 08:11:51.000000000 -0800
@@ -25,10 +25,13 @@
*/
void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size)
{
- if (pat_wc_enabled)
+ if (pat_wc_enabled) {
+ printk(KERN_INFO "ioremap_wc: addr %lx, size %lx\n",
+ phys_addr, size);
return __ioremap(phys_addr, size, _PAGE_WC);
- else
+ } else {
return ioremap_nocache(phys_addr, size);
+ }
}
EXPORT_SYMBOL(ioremap_wc);

Index: linux-2.6.git/arch/x86/mm/ioremap_32.c
===================================================================
--- linux-2.6.git.orig/arch/x86/mm/ioremap_32.c 2008-01-17 03:18:59.000000000 -0800
+++ linux-2.6.git/arch/x86/mm/ioremap_32.c 2008-01-17 08:10:58.000000000 -0800
@@ -164,6 +164,8 @@

void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
{
+ printk(KERN_INFO "ioremap_nocache: addr %lx, size %lx\n",
+ phys_addr, size);
return __ioremap(phys_addr, size, _PAGE_UC);
}
EXPORT_SYMBOL(ioremap_nocache);
Index: linux-2.6.git/arch/x86/mm/ioremap_64.c
===================================================================
--- linux-2.6.git.orig/arch/x86/mm/ioremap_64.c 2008-01-17 03:18:59.000000000 -0800
+++ linux-2.6.git/arch/x86/mm/ioremap_64.c 2008-01-17 08:10:13.000000000 -0800
@@ -144,7 +144,7 @@

void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
{
- printk(KERN_DEBUG "ioremap_nocache: addr %lx, size %lx\n",
+ printk(KERN_INFO "ioremap_nocache: addr %lx, size %lx\n",
phys_addr, size);
return __ioremap(phys_addr, size, _PAGE_UC);
}
Index: linux-2.6.git/arch/x86/mm/pat.c
===================================================================
--- linux-2.6.git.orig/arch/x86/mm/pat.c 2008-01-17 03:18:59.000000000 -0800
+++ linux-2.6.git/arch/x86/mm/pat.c 2008-01-17 08:06:23.000000000 -0800
@@ -170,7 +170,7 @@

if (!fattr && attr != ml->attr) {
printk(
- KERN_DEBUG "%s:%d conflicting cache attribute %Lx-%Lx %s<->%s\n",
+ KERN_WARNING "%s:%d conflicting cache attribute %Lx-%Lx %s<->%s\n",
current->comm, current->pid,
start, end,
cattr_name(attr), cattr_name(ml->attr));
@@ -205,7 +205,7 @@
list_for_each_entry(ml, &mattr_list, nd) {
if (ml->start == start && ml->end == end) {
if (ml->attr != attr)
- printk(KERN_DEBUG
+ printk(KERN_WARNING
"%s:%d conflicting cache attributes on free %Lx-%Lx %s<->%s\n",
current->comm, current->pid, start, end,
cattr_name(attr), cattr_name(ml->attr));
@@ -217,7 +217,7 @@
}
spin_unlock(&mattr_lock);
if (err)
- printk(KERN_DEBUG "%s:%d freeing invalid mattr %Lx-%Lx %s\n",
+ printk(KERN_WARNING "%s:%d freeing invalid mattr %Lx-%Lx %s\n",
current->comm, current->pid,
start, end, cattr_name(attr));
return err;
Index: linux-2.6.git/include/asm-x86/io_32.h
===================================================================
--- linux-2.6.git.orig/include/asm-x86/io_32.h 2008-01-17 06:28:06.000000000 -0800
+++ linux-2.6.git/include/asm-x86/io_32.h 2008-01-17 08:09:30.000000000 -0800
@@ -113,6 +113,8 @@

static inline void __iomem * ioremap(unsigned long offset, unsigned long size)
{
+ printk(KERN_INFO "ioremap: addr %lx, size %lx\n",
+ offset, size);
return __ioremap(offset, size, 0);
}

Index: linux-2.6.git/include/asm-x86/io_64.h
===================================================================
--- linux-2.6.git.orig/include/asm-x86/io_64.h 2008-01-17 08:08:23.000000000 -0800
+++ linux-2.6.git/include/asm-x86/io_64.h 2008-01-17 08:08:44.000000000 -0800
@@ -154,7 +154,7 @@

static inline void __iomem * ioremap (unsigned long offset, unsigned long size)
{
- printk(KERN_DEBUG "ioremap: addr %lx, size %lx\n",
+ printk(KERN_INFO "ioremap: addr %lx, size %lx\n",
offset, size);
return __ioremap(offset, size, 0);
}