Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751560AbWEEOeK (ORCPT ); Fri, 5 May 2006 10:34:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751565AbWEEOeK (ORCPT ); Fri, 5 May 2006 10:34:10 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:1971 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751560AbWEEOeJ (ORCPT ); Fri, 5 May 2006 10:34:09 -0400 Subject: Re: assert/crash in __rmqueue() when enabling CONFIG_NUMA From: Dave Hansen To: Bob Picco Cc: Andy Whitcroft , Ingo Molnar , Nick Piggin , "Martin J. Bligh" , Andi Kleen , linux-kernel@vger.kernel.org, Andrew Morton , Linux Memory Management In-Reply-To: <20060505135503.GA5708@localhost> References: <20060502070618.GA10749@elte.hu> <200605020905.29400.ak@suse.de> <44576688.6050607@mbligh.org> <44576BF5.8070903@yahoo.com.au> <20060504013239.GG19859@localhost> <1146756066.22503.17.camel@localhost.localdomain> <20060504154652.GA4530@localhost> <20060504192528.GA26759@elte.hu> <20060504194334.GH19859@localhost> <445A7725.8030401@shadowen.org> <20060505135503.GA5708@localhost> Content-Type: text/plain Date: Fri, 05 May 2006 07:33:10 -0700 Message-Id: <1146839590.22503.48.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1198 Lines: 28 On Fri, 2006-05-05 at 09:55 -0400, Bob Picco wrote: > - if (!page_is_buddy(buddy, order)) > + if (page_in_zone_hole(buddy)) > + break; > + else if (page_zonenum(buddy) != page_zonenum(page)) > + break; > + else if (!page_is_buddy(buddy, order)) > break; /* Move the buddy up one level. */ The page_zonenum() checks look good, but I'm not sure I understand the page_in_zone_hole() part. If a page is in a hole in a zone, it will still have a valid mem_map entry, right? It should also never have been put into the allocator, so it also won't ever be coalesced. I'm a bit confused. :( BTW, I like the idea of just aligning HIGHMEM's start because it has no runtime cost. Buuuuut, it is still just a shift and compare of the two page->flags, which should already be (or will soon anyway be) in the cache. -- Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/