Re: [discuss] 2.6.19-rc6: known regressions (v4)

On Wed, Nov 22, 2006 at 05:05:49PM +0100, Andre Noll wrote:
> Unfortunately, yes. I tried rc6, current git, and currrent git + David
> Rientjes' patch. They all show the same behaviour.

I must have missed that patch.
> 
> > It's probably another bug in the memmap parsing rewrite (Mel cc'ed) 
> > but the debugging information in the standard kernel unfortunately
> > doesn't give enough output to find out where it happens.
> 
> Feel free to send me a debugging patch..

Here's one. Please send output (unless Mel finds the problem first..)

-Andi

Index: linux-2.6.19-rc6-hack/mm/page_alloc.c
===================================================================
--- linux-2.6.19-rc6-hack/mm/page_alloc.c
+++ linux-2.6.19-rc6-hack/mm/page_alloc.c
@@ -188,6 +188,10 @@ static inline int bad_range(struct zone 
 
 static void bad_page(struct page *page)
 {
+       static int warned; 
+       if (!warned) { 
+       warned = 1;
+       printk(KERN_EMERG "page address %lx\n", page_address(page));
        printk(KERN_EMERG "Bad page state in process '%s'\n"
                KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d 
count:%d\n"
                KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
@@ -196,6 +200,7 @@ static void bad_page(struct page *page)
                (unsigned long)page->flags, page->mapping,
                page_mapcount(page), page_count(page));
        dump_stack();
+       }
        page->flags &= ~(1 << PG_lru    |
                        1 << PG_private |
                        1 << PG_locked  |