From patchwork Mon Jan 5 13:49:52 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandru X-Patchwork-Id: 16613 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id F127DDE272 for ; Tue, 6 Jan 2009 00:50:17 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from e23smtp04.au.ibm.com (E23SMTP04.au.ibm.com [202.81.18.173]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp04.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 8A0D6DE001 for ; Tue, 6 Jan 2009 00:49:57 +1100 (EST) Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp04.au.ibm.com (8.13.1/8.13.1) with ESMTP id n05DmHEJ005181 for ; Tue, 6 Jan 2009 00:48:17 +1100 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id n05Dns95223440 for ; Tue, 6 Jan 2009 00:49:54 +1100 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n05DnrCs006802 for ; Tue, 6 Jan 2009 00:49:53 +1100 Received: from [9.124.35.51] ([9.124.35.51]) by d23av02.au.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id n05Dnqeo006784; Tue, 6 Jan 2009 00:49:52 +1100 From: Chandru Organization: ibm To: Dave Hansen Subject: Re: 2.6.28-rc9 panics with crashkernel=256M while booting Date: Mon, 5 Jan 2009 19:19:52 +0530 User-Agent: KMail/1.9.10 References: <200812241325.49404.chandru@in.ibm.com> <18772.11376.339295.42622@cargo.ozlabs.ibm.com> <1230586567.19452.100.camel@nimitz> In-Reply-To: <1230586567.19452.100.camel@nimitz> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200901051919.52327.chandru@in.ibm.com> Cc: linuxppc-dev@ozlabs.org, Andrew Morton , Paul Mackerras , linux-kernel@vger.kernel.org X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org On Tuesday 30 December 2008 03:06:07 Dave Hansen wrote: > On Fri, 2008-12-26 at 11:59 +1100, Paul Mackerras wrote: > > > + } > > > + > > > + for_each_online_node(nid) { > > > /* > > > - * Be very careful about moving this around. Future > > > - * calls to careful_allocation() depend on this getting > > > - * done correctly. > > > + * Be very careful about moving this around. > > > */ > > > mark_reserved_regions_for_nid(nid); > > > sparse_memory_present_with_active_regions(nid); > > I think this reintroduces one of the bugs that I squashed. You *have* > to call mark_reserved_regions_for_nid() right after you do > free_bootmem_with_active_regions(). Otherwise, someone else can > bootmem_alloc() a reserved region from that node. Thanks for the review comments Dave. With the commit:a4c74ddd5ea3db53fc73d29c222b22656a7d05be, I see this has been taken care in mark_reserved_regions_for_nid(). In that case we may only need the change made in reserve_bootmem_node(). Hello Andrew, Could you please consider the following patch instead of the original patch in this thread. Thanks, When booted with crashkernel=224M@32M or any memory size less than this, the system boots properly. The system comes up with two nodes (0-256M and 256M-4GB). The crashkernel memory reservation spans across these two nodes. The mark_reserved_regions_for_nid() in arch/powerpc/numa.c resizes the reserved part of the memory within it as... if (end_pfn > node_ar.end_pfn) reserve_size = (node_ar.end_pfn << PAGE_SHIFT) - (start_pfn << PAGE_SHIFT); but the reserve_bootmem_node() in mm/bootmem.c raises the pfn value of end end = PFN_UP(physaddr + size); This causes end to get a value past the last page in the 0-256M node. The following change restricts the value of end if it exceeds the last pfn in a given node. Signed-off-by: Chandru S Cc: Dave Hansen --- mm/bootmem.c | 4 ++++ 1 file changed, 4 insertions(+) --- linux-2.6.28/mm/bootmem.c.orig 2009-01-05 20:42:12.000000000 +0530 +++ linux-2.6.28/mm/bootmem.c 2009-01-05 20:43:53.000000000 +0530 @@ -375,10 +375,14 @@ int __init reserve_bootmem_node(pg_data_ unsigned long size, int flags) { unsigned long start, end; + bootmem_data_t *bdata = pgdat->bdata; start = PFN_DOWN(physaddr); end = PFN_UP(physaddr + size); + if (end > bdata->node_low_pfn) + end = bdata->node_low_pfn; + return mark_bootmem_node(pgdat->bdata, start, end, 1, flags); }