From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Jul 2005 18:17:24 -0700 From: Andrew Morton Subject: Re: [patch] mm: Ensure proper alignment for node_remap_start_pfn Message-Id: <20050727181724.36bd28ed.akpm@osdl.org> In-Reply-To: <20050728004241.GA16073@localhost.localdomain> References: <20050728004241.GA16073@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ravikiran G Thirumalai Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, shai@scalex86.org List-ID: Ravikiran G Thirumalai wrote: > > While reserving KVA for lmem_maps of node, we have to make sure that > node_remap_start_pfn[] is aligned to a proper pmd boundary. > (node_remap_start_pfn[] gets its value from node_end_pfn[]) > What are the effects of not having this patch applied? Does someone's computer crash, or what? IOW: what problem is this fixing, precisely? > > Index: linux-2.6.13-rc3/arch/i386/mm/discontig.c > =================================================================== > --- linux-2.6.13-rc3.orig/arch/i386/mm/discontig.c 2005-07-26 15:10:25.000000000 -0700 > +++ linux-2.6.13-rc3/arch/i386/mm/discontig.c 2005-07-26 16:27:43.000000000 -0700 > @@ -243,6 +243,14 @@ > /* now the roundup is correct, convert to PAGE_SIZE pages */ > size = size * PTRS_PER_PTE; > > + if (node_end_pfn[nid] & (PTRS_PER_PTE-1)) { > + /* > + * Adjust size if node_end_pfn is not on a proper > + * pmd boundary. remap_numa_kva will barf otherwise. > + */ > + size += node_end_pfn[nid] & (PTRS_PER_PTE-1); > + } > + > /* > * Validate the region we are allocating only contains valid > * pages. -- 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/ . Don't email: email@kvack.org