Re: [Stable-review] [36/55] [PARISC] slub: fix panic with DISCONTIGMEM

[Ben Hutchings <ben@decadent.org.uk>]

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On Fri, 2011-04-29 at 11:55 -0700, Greg KH wrote:
> 2.6.38-stable review patch.  If anyone has any objections, please let us know.
> 
> ------------------
> 
> From: James Bottomley <James.Bottomley@HansenPartnership.com>
> 
> commit 4a5fa3590f09999f6db41bc386bce40848fa9f63 upstream.
> 
> Slub makes assumptions about page_to_nid() which are violated by
> DISCONTIGMEM and !NUMA.  This violation results in a panic because
> page_to_nid() can be non-zero for pages in the discontiguous ranges and
> this leads to a null return by get_node().  The assertion by the
> maintainer is that DISCONTIGMEM should only be allowed when NUMA is also
> defined.  However, at least six architectures: alpha, ia64, m32r, m68k,
> mips, parisc violate this.  The panic is a regression against slab, so
> just mark slub broken in the problem configuration to prevent users
> reporting these panics.

This stable series also included the patches:

commit 6a682f634ba9615d3498d1e20a23e9d4fcb39f16
Author: David Rientjes <rientjes@google.com>
Date:   Wed Apr 20 19:27:13 2011 -0700

    set memory ranges in N_NORMAL_MEMORY when onlined
    
    commit d9b41e0b54fd7e164daf1e9c539c1070398aa02e upstream.

commit 8858587af25efc06d5cce42676786b3d7a9160f2
Author: Michael Schmitz <schmitzmic@googlemail.com>
Date:   Tue Apr 26 14:51:53 2011 +1200

    m68k/mm: Set all online nodes in N_NORMAL_MEMORY
    
    commit 4aac0b4815ba592052758f4b468f253d383dc9d6 upstream.

which look like they're supposed to make slub work on these two
architectures (parisc and m68k).  Do they?  If not, do they fix a
different problem?

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.

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