From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 94BB08D003B for ; Tue, 19 Apr 2011 18:04:35 -0400 (EDT) Date: Tue, 19 Apr 2011 17:04:31 -0500 (CDT) From: Christoph Lameter Subject: Re: slub: fix panic with DISCONTIGMEM In-Reply-To: <1303249970.11237.30.camel@mulgrave.site> Message-ID: References: <1303248576.11237.23.camel@mulgrave.site> <1303249970.11237.30.camel@mulgrave.site> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: James Bottomley Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, "hugh.dickins@tiscali.co.uk" , Parisc List On Tue, 19 Apr 2011, James Bottomley wrote: > On Tue, 2011-04-19 at 16:38 -0500, Christoph Lameter wrote: > > On Tue, 19 Apr 2011, James Bottomley wrote: > > > > > Slub makes assumptions about page_to_nid() which are violated by > > > DISCONTIGMEM and !NUMA. This violation results in a panic because > > > > Fix this by stating correctly by saying "The kernel makes assumptions in > > various subsystems ..." > > Slub is a subset of the kernel, so the original wording is a bit more > precise. F.e. hugepage support does the same thing. So it not slub specific. > Well, we can discuss how to proceed going forwards. The current fact is > that any prior kernel that enables SLUB with DISCONTIGMEM and !NUMA will > eventually go boom when the page allocator returns a page not in the > first pfn array. That has to be fixed in -stable. I don't really think > a DISCONTIGMEM re-engineering effort would be the best thing for the > -stable series. As far as I can tell: It will go boom even with other subsystems. I am surprised that we have never seen this before. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org