Re: [BUG] sysrq-m oops

["Bob Picco" <bob.picco@hp.com>]

Chuck Ebbert wrote:	[Thu Jun 07 2007, 11:42:38AM EDT]
> On 06/06/2007 08:27 PM, john stultz wrote:
> > Hey All,
> > 	With 2.6.21 and the current -git, we're seeing the following oops when
> > we try sysrq-m:
> > 
> 
> It's here in arch/x86_64/mm/init.c::show_mem():
> 
>         for_each_online_pgdat(pgdat) {
>                for (i = 0; i < pgdat->node_spanned_pages; ++i) {
This is probably with sparsemem? I'm working with acme@redhat.com to
test a patch. Basically you need to validate the pfn because it
could be in a hole. Most arches which support sparsemem perform this
check.

			if (!pfn_valid(pgdat->node_start_pfn + i))
				continue;
bob
>                         page = pfn_to_page(pgdat->node_start_pfn + i);
>                         total++;
>  ======>                if (PageReserved(page))
>                                 reserved++;
>                         else if (PageSwapCache(page))
>                                 cached++;
>                         else if (page_count(page))
>                                 shared += page_count(page) - 1;
>                }
>         }
> 
> page is completely bogus (it's 0x0000000003480000)
> -
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