Re: New debugging patch was Re: x86-64 bad pmds in 2.6.11.6 II

[Dave Jones <davej@redhat.com>]

On Wed, Apr 27, 2005 at 04:23:44PM +0200, Andi Kleen wrote:
 > 
 > Could someone who reproduces this problem apply the following
 > patch and see if the WARN_ON triggers?
 > 
 > 
 > diff -u linux-2.6.11/mm/memory.c-o linux-2.6.11/mm/memory.c
 > --- linux-2.6.11/mm/memory.c-o	2005-03-02 08:38:08.000000000 +0100
 > +++ linux-2.6.11/mm/memory.c	2005-04-27 15:48:19.777104735 +0200
 > @@ -94,6 +94,7 @@
 >  	if (pmd_none(*pmd))
 >  		return;
 >  	if (unlikely(pmd_bad(*pmd))) {
 > +		printk("%s:%d: ", current->comm, current->pid);
 >  		pmd_ERROR(*pmd);
 >  		pmd_clear(pmd);
 >  		return;
 > @@ -113,6 +114,7 @@
 >  	unsigned long addr = start, next;
 >  	pmd_t *pmd, *__pmd;
 >  
 > +	WARN_ON(start == end);
 >  	if (pud_none(*pud))
 >  		return;
 >  	if (unlikely(pud_bad(*pud))) {

I'm up to my eyeballs in other stuff right now, so probably won't
get a chance to test this personally. I'll add it to the Fedora
testing rpm however, as 1-2 users are also hitting it.

I'll let you know if I hear anything back.

		Dave