Re: [BUG?] numa required on x86_64?

[Ian Kumlien <pomac@vapor.com>]

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On fre, 2011-06-24 at 15:23 -0700, Randy Dunlap wrote:
> On Sat, 25 Jun 2011 00:00:58 +0200 Ian Kumlien wrote:
> 
> > Hi all,
> > 
> > Just found this when wanting to play with development kernels again.
> > Since there is no -gitXX snapshots anymore, I cloned the git =)...
> > 
> > But, it failed to build properly with my config:
> > 
> > mm/page_cgroup.c line 308: node_start_pfn and node_end_pfn is only
> > defined under NUMA on x86_64.
> > 
> > The commit that changed the use of this was introduced recently while
> > the mmzone_64.h hasn't been changed since april.
> 
> You should have cc-ed the commit Author (I did so).

Sorry, tired and i was upgrading systems at work when i found this =)

> > commit 37573e8c718277103f61f03741bdc5606d31b07e
> > Author: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> > Date:   Wed Jun 15 15:08:42 2011 -0700
> > 
> >     memcg: fix init_page_cgroup nid with sparsemem
> >     
> >     Commit 21a3c9646873 ("memcg: allocate memory cgroup structures in local
> >     nodes") makes page_cgroup allocation as NUMA aware.  But that caused a
> >     problem https://bugzilla.kernel.org/show_bug.cgi?id=36192.
> >     
> >     The problem was getting a NID from invalid struct pages, which was not
> >     initialized because it was out-of-node, out of [node_start_pfn,
> >     node_end_pfn)
> >     
> >     Now, 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.)
> >     
> >     [akpm@linux-foundation.org: try to fix up comments]
> >     Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> >     Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> >     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> 
> A patch for this has been posted at least 2 times.
> It's here:  http://marc.info/?l=linux-mm&m=130827204306775&w=2
> 
> Andrew, please merge this (^that^) patch.

Damn, i haven't been following LKML that closely recently =/

> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***

-- 
Ian Kumlien  -- http://demius.net || http://pomac.netswarm.net

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