From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 20 Jul 2002 16:21:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 20 Jul 2002 16:20:03 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:43764 "EHLO hermes.mvista.com") by vger.kernel.org with ESMTP id ; Sat, 20 Jul 2002 16:19:22 -0400 Subject: [PATCH] for_each_zone From: Robert Love To: akpm@zip.com.au, torvalds@transmeta.com Cc: riel@conectiva.com.br, linux-kernel@vger.kernel.org, linux-mm@kvack.org, wli@holomorphy.com Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 Date: 20 Jul 2002 13:22:23 -0700 Message-Id: <1027196543.1555.775.camel@sinai> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Attached patch implements for_each_zone(zont_t *) which is a helper macro to cleanup code of the form: for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next) { for (i = 0; i < MAX_NR_ZONES; ++i) { zone_t * z = pgdat->node_zones + i; /* ... */ } } and replace it with: for_each_zone(zone) { /* ... */ } This patch only replaces one use of the above loop with the new macro. Pending code, however, currently in the full rmap patch uses for_each_zone more extensively. This is from Rik's 2.4-rmap patch and by William Irwin. This patch requires the previous for_each_pgdat patch, but only to apply cleanly. Robert Love diff -urN linux-2.5.27/include/linux/mmzone.h linux/include/linux/mmzone.h --- linux-2.5.27/include/linux/mmzone.h Sat Jul 20 12:11:05 2002 +++ linux/include/linux/mmzone.h Sat Jul 20 13:00:48 2002 @@ -163,6 +163,43 @@ extern pg_data_t contig_page_data; +/* + * next_zone - helper magic for for_each_zone() + * Thanks to William Lee Irwin III for this piece of ingenuity. + */ +static inline zone_t * next_zone(zone_t * zone) +{ + pg_data_t *pgdat = zone->zone_pgdat; + + if (zone - pgdat->node_zones < MAX_NR_ZONES - 1) + zone++; + else if (pgdat->node_next) { + pgdat = pgdat->node_next; + zone = pgdat->node_zones; + } else + zone = NULL; + + return zone; +} + +/** + * for_each_zone - helper macro to iterate over all memory zones + * @zone - pointer to zone_t variable + * + * The user only needs to declare the zone variable, for_each_zone + * fills it in. This basically means for_each_zone() is an + * easier to read version of this piece of code: + * + * for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next) + * for (i = 0; i < MAX_NR_ZONES; ++i) { + * zone_t * z = pgdat->node_zones + i; + * ... + * } + * } + */ +#define for_each_zone(zone) \ + for (zone = pgdat_list->node_zones; zone; zone = next_zone(zone)) + #ifndef CONFIG_DISCONTIGMEM #define NODE_DATA(nid) (&contig_page_data) diff -urN linux-2.5.27/mm/page_alloc.c linux/mm/page_alloc.c --- linux-2.5.27/mm/page_alloc.c Sat Jul 20 12:11:07 2002 +++ linux/mm/page_alloc.c Sat Jul 20 13:00:48 2002 @@ -477,12 +477,12 @@ */ unsigned int nr_free_pages(void) { - unsigned int i, sum = 0; - pg_data_t *pgdat; + unsigned int sum; + zone_t *zone; - for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next) - for (i = 0; i < MAX_NR_ZONES; ++i) - sum += pgdat->node_zones[i].free_pages; + sum = 0; + for_each_zone(zone) + sum += zone->free_pages; return sum; }