From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <43FBD995.20601@jp.fujitsu.com> Date: Wed, 22 Feb 2006 12:25:09 +0900 From: KAMEZAWA Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH] remove zone_mem_map References: <43FBAEBA.2020300@jp.fujitsu.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Linux Kernel Mailing List , linux-mm , Dave Hansen , Andrew Morton List-ID: Christoph Lameter wrote: > On Wed, 22 Feb 2006, KAMEZAWA Hiroyuki wrote: > >> This patch removes zone_mem_map. > > Note that IA64 does not seem to depend on zone_mem_map... > Oh, yes. ia64 doesn't includes asm-generic/memory_model.h when DISCONTIGMEM. >> Index: test/include/asm-generic/memory_model.h >> =================================================================== >> --- test.orig/include/asm-generic/memory_model.h >> +++ test/include/asm-generic/memory_model.h >> @@ -47,9 +47,9 @@ extern unsigned long page_to_pfn(struct >> >> #define page_to_pfn(pg) \ >> ({ struct page *__pg = (pg); \ >> - struct zone *__zone = page_zone(__pg); \ >> - (unsigned long)(__pg - __zone->zone_mem_map) + \ >> - __zone->zone_start_pfn; \ >> + struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \ >> + (unsigned long)(__pg - __pgdat->node_mem_map) + \ >> + __pgdat->node_start_pfn; \ >> }) > > NODE_DATA is an arch specific lookup, If it always is a table lookup > then the performance will be comparable to page_zone because that also > involves one table lookup. > There are several types of NODE_DATA definitions. 1. #define NODE_DATA(node) (&node_data[node]) alpha,arm, 2. #define NODE_DATA(node) (node_data[node]) i386,powerpc,x86_64,m32r 3. #define NODE_DATA(node) (&node_data[node]->pgdat) parisc,mips 4. #define NODE_DATA(node) (per-cpu-page has node_data[nid] pointer array) ia64 BTW, ia64 looks very special. Does it make sensible performance gain ? -- Kame -- 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