Re: [Bugme-new] [Bug 36192] New: Kernel panic when boot the 2.6.39+ kernel based off of 2.6.32 kernel

[Mel Gorman <mgorman@suse.de>]

On Wed, Jun 08, 2011 at 05:45:05PM +0900, KAMEZAWA Hiroyuki wrote:
> > > <SNIP>
> > > +			/*
> > > +			 * Nodes can be overlapped
> > > +			 * We know some arch can have nodes layout as
> > > +			 * -------------pfn-------------->
> > > +			 * N0 | N1 | N2 | N0 | N1 | N2 |.....
> > > +			 */
> > > +			if (pfn_to_nid(pfn) != node)
> > > +				continue;
> > > +			fail = init_section_page_cgroup(pfn, node);
> > > +		}
> > >  	}
> > >  	if (fail) {
> > >  		printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
> > > 
> > 
> > FWIW, overall I think this is heading in the right direction.
> > 
> Thank you. and I noticed I misunderstood what ALIGN() does.
> 

And I missed it :/

> This patch is made agaisnt the latest mainline git tree.
> Tested on my host, at least.
> ==
> From 0485201fec6a9bbfabc4c2674756360c05080155 Mon Sep 17 00:00:00 2001
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Date: Wed, 8 Jun 2011 17:13:37 +0900
> Subject: [PATCH] [BUGFIX] Avoid getting nid from invalid struct page at page_cgroup allocation.
> 
> With sparsemem, page_cgroup_init scans pfn from 0 to max_pfn.
> But this may scan a pfn which is not on any node and can access
> memmap which is not initialized.
> 
> This makes page_cgroup_init() for SPARSEMEM node aware and remove
> a code to get nid from page->flags. (Then, we'll use valid NID
> always.)
> 
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> 

I do not see any problems now. Thanks!

Acked-by: Mel Gorman <mgorman@suse.de>

-- 
Mel Gorman
SUSE Labs

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