From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: slub: fix panic with DISCONTIGMEM Date: Tue, 19 Apr 2011 16:29:36 -0500 Message-ID: <1303248576.11237.23.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Christoph Lameter To: linux-arch@vger.kernel.org, linux-mm@vger.kernel.org, Parisc List Return-path: List-ID: List-Id: linux-parisc.vger.kernel.org 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. Cc: stable@kernel.org Signed-off-by: James Bottomley --- diff --git a/init/Kconfig b/init/Kconfig index 56240e7..a7ad8fb 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1226,6 +1226,7 @@ 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