From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 18 Sep 2006 18:20:32 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH] Get rid of zone_table V2 In-Reply-To: <20060918173134.d3850903.akpm@osdl.org> Message-ID: References: <20060918132818.603196e2.akpm@osdl.org> <20060918161528.9714c30c.akpm@osdl.org> <20060918165808.c410d1d4.akpm@osdl.org> <20060918173134.d3850903.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org, Andy Whitcroft , Dave Hansen List-ID: On Mon, 18 Sep 2006, Andrew Morton wrote: > Which is pretty much the same thing. I assume your objdump was of > an unlinked .o file, so contig_page_data shows up as 0x0. Correct. > The code looks OK though. > > It would be nice to be able to reclaim a few bits from page->flags - we're > awfully short on them. With the zone reduction patchset we already have an additional bit. If you look at the i386 code it does an "and 1,ax". With the optional zone dma patch we will have an additional bit because then there are no zones anymore for SMP and UP. At that point page_zone() becomes a constant. The node id is essential for NUMA locality and we cannot easily remove that from the page flags without additional lookups. Configurations using DISCONTIG do not need the section bits that sparsemem requires. Sparsemem is tunable though. If you configure coarser granularity then more bits can be recovered. -- 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