From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 8 May 2002 04:06:58 -0700 (PDT) From: Samuel Ortiz Subject: Re: [PATCH] rmap 13a In-Reply-To: <20020507183741.A25245@infradead.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Hellwig Cc: Rik van Riel , linux-mm@kvack.org List-ID: On Tue, 7 May 2002, Christoph Hellwig wrote: > On Mon, May 06, 2002 at 11:17:26PM -0300, Rik van Riel wrote: > > rmap 13a: > > - NUMA changes for page_address (Samuel Ortiz) > > I don't think the changes makes sense. If calculating page_address is > complicated and slow enough to place it out-of-lin using page->virtual > is much better. This is right for machines who don't care about the struct page size, like SGI ones, and big NUMA machines in general. > I'd suggest backing this patch out and instead always maintain page->virtual > for discontigmem. While at this as a little cleanup you might want to > define WANT_PAGE_VIRTUAL based on CONFIG_HIGHMEM || CONFIG_DISCONTIGMEM > at the top of mm.h instead of cluttering it up. Some discontiguous architectures (ARM, for example) may be interested in getting rid of page->virtual, and thus shrinking the struct page size. So you may want to get the possibility of having (!CONFIG_HIGHMEM)&&CONFIG_DISCONTIGMEM and not wanting page->virtual. So, WANT_PAGE_VIRTUAL can not be defined with CONFIG_HIGHMEM || CONFIG_DISCONTIGMEM. However, I should modify my patch in order for the changes to take place only if (!CONFIG_HIGHMEM)&&(CONFIG_DISCONTIG_MEM)&&(!WANT_PAGE_VIRTUAL). I can come back with the right changes if that makes sense to you. Cheers, Samuel. -- 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/