From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120205220949.536346997@pcw.home.local> Date: Sun, 05 Feb 2012 23:09:51 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Rientjes , Pekka Enberg , James Bottomley , Greg KH Subject: [PATCH 02/91] slub: fix panic with DISCONTIGMEM In-Reply-To: <0635750f5f06ed2ca212b91fcb5c4483@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.27-longterm review patch. If anyone has any objections, please let us know. ------------------ 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 Acked-by: Pekka Enberg Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- init/Kconfig | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) Index: longterm-2.6.27/init/Kconfig =================================================================== --- longterm-2.6.27.orig/init/Kconfig 2012-02-05 22:34:35.012915163 +0100 +++ longterm-2.6.27/init/Kconfig 2012-02-05 22:34:35.225915821 +0100 @@ -747,6 +747,7 @@ a slab allocator. config SLUB + depends on BROKEN || NUMA || !DISCONTIGMEM bool "SLUB (Unqueued Allocator)" help SLUB is a slab allocator that minimizes cache line usage