From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <476B9000.2090707@de.ibm.com> Date: Fri, 21 Dec 2007 11:05:52 +0100 From: Carsten Otte Reply-To: carsteno@de.ibm.com MIME-Version: 1.0 Subject: Re: [rfc][patch 2/2] xip: support non-struct page memory References: <20071214133817.GB28555@wotan.suse.de> <20071214134106.GC28555@wotan.suse.de> <476A73F0.4070704@de.ibm.com> <476A7D21.7070607@de.ibm.com> <20071221004556.GB31040@wotan.suse.de> In-Reply-To: <20071221004556.GB31040@wotan.suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: carsteno@de.ibm.com, Jared Hulbert , Linux Memory Management List , Martin Schwidefsky , Heiko Carstens List-ID: Nick Piggin wrote: > So then you're back to needing struct pages again. Do you allocate > them at hotplug time? They get allocated by cathing kernel page faults when accessing the mem_map array and filling in pages on demand. This happens at hotplug time, where we initialize the content of struct page. > AFAIK, sparsemem keeps track of all sections for pfn_valid(), which would > work. Any plans to convert s390 to it? ;) I think vmem_map is superior to sparsemem, because a single-dimensional mem_map array is faster work with (single step lookup). And we've got plenty of virtual address space for the vmem_map array on 64bit. -- 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