slub: fix panic with DISCONTIGMEM

commit 4a5fa3590f 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@google.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
James Bottomley 2011-04-19 16:29:36 -05:00 committed by Greg Kroah-Hartman
parent 69c74edcf1
commit 19074fe067

View File

@ -1070,6 +1070,7 @@ config SLAB
per cpu and per node queues.
config SLUB
depends on BROKEN || NUMA || !DISCONTIGMEM
bool "SLUB (Unqueued Allocator)"
help
SLUB is a slab allocator that minimizes cache line usage