Re: [PATCH 02/91] slub: fix panic with DISCONTIGMEM

From: Willy Tarreau
Date: Tue Feb 07 2012 - 01:14:13 EST

On Mon, Feb 06, 2012 at 01:58:56PM -0800, David Rientjes wrote:
> On Sun, 5 Feb 2012, Willy Tarreau wrote:
> > 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.
> >
> > Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
> > Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
> > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
> The problem that this patch initially addressed is fixed by the next patch
> in your series, "set memory ranges in N_NORMAL_MEMORY when onlined", so I
> don't think this one should be merged.

Perfect, I'm dropping it then.

Thank you David,

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