From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 7 Feb 2012 07:13:57 +0100 From: Willy Tarreau To: David Rientjes Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Pekka Enberg , James Bottomley , Greg KH Subject: Re: [PATCH 02/91] slub: fix panic with DISCONTIGMEM Message-ID: <20120207061357.GA26009@1wt.eu> References: <20120205220949.536346997@pcw.home.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 > > Acked-by: Pekka Enberg > > Signed-off-by: James Bottomley > > Signed-off-by: Greg Kroah-Hartman > > 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, Willy