Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656AbZAENuL (ORCPT ); Mon, 5 Jan 2009 08:50:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752156AbZAENt6 (ORCPT ); Mon, 5 Jan 2009 08:49:58 -0500 Received: from E23SMTP06.au.ibm.com ([202.81.18.175]:47146 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751718AbZAENt6 (ORCPT ); Mon, 5 Jan 2009 08:49:58 -0500 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 Cc: Paul Mackerras , Andrew Morton , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Benjamin Herrenschmidt 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-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200901051919.52327.chandru@in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2857 Lines: 68 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); } -- 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/