From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755106Ab0DORVq (ORCPT ); Thu, 15 Apr 2010 13:21:46 -0400 Received: from gir.skynet.ie ([193.1.99.77]:49748 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754922Ab0DORVl (ORCPT ); Thu, 15 Apr 2010 13:21:41 -0400 From: Mel Gorman To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Chris Mason , Dave Chinner , KOSAKI Motohiro , Andi Kleen , Johannes Weiner , Mel Gorman Subject: [PATCH 01/10] vmscan: kill prev_priority completely Date: Thu, 15 Apr 2010 18:21:34 +0100 Message-Id: <1271352103-2280-2-git-send-email-mel@csn.ul.ie> X-Mailer: git-send-email 1.6.5 In-Reply-To: <1271352103-2280-1-git-send-email-mel@csn.ul.ie> References: <1271352103-2280-1-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: KOSAKI Motohiro Since 2.6.28 zone->prev_priority is unused. Then it can be removed safely. It reduce stack usage slightly. Now I have to say that I'm sorry. 2 years ago, I thghout prev_priority can be integrate again, it's useful. but four (or more) times trying haven't got good performance number. thus I give up such approach. Signed-off-by: KOSAKI Motohiro --- include/linux/mmzone.h | 15 ------------- mm/page_alloc.c | 2 - mm/vmscan.c | 54 ++--------------------------------------------- mm/vmstat.c | 2 - 4 files changed, 3 insertions(+), 70 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index cf9e458..ad76962 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -339,21 +339,6 @@ struct zone { atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; /* - * prev_priority holds the scanning priority for this zone. It is - * defined as the scanning priority at which we achieved our reclaim - * target at the previous try_to_free_pages() or balance_pgdat() - * invocation. - * - * We use prev_priority as a measure of how much stress page reclaim is - * under - it drives the swappiness decision: whether to unmap mapped - * pages. - * - * Access to both this field is quite racy even on uniprocessor. But - * it is expected to average out OK. - */ - int prev_priority; - - /* * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on * this zone's LRU. Maintained by the pageout code. */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d03c946..88513c0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3862,8 +3862,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, zone_seqlock_init(zone); zone->zone_pgdat = pgdat; - zone->prev_priority = DEF_PRIORITY; - zone_pcp_init(zone); for_each_lru(l) { INIT_LIST_HEAD(&zone->lru[l].list); diff --git a/mm/vmscan.c b/mm/vmscan.c index 3ff3311..1db19f8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1277,20 +1277,6 @@ done: } /* - * We are about to scan this zone at a certain priority level. If that priority - * level is smaller (ie: more urgent) than the previous priority, then note - * that priority level within the zone. This is done so that when the next - * process comes in to scan this zone, it will immediately start out at this - * priority level rather than having to build up its own scanning priority. - * Here, this priority affects only the reclaim-mapped threshold. - */ -static inline void note_zone_scanning_priority(struct zone *zone, int priority) -{ - if (priority < zone->prev_priority) - zone->prev_priority = priority; -} - -/* * This moves pages from the active list to the inactive list. * * We move them the other way if the page is referenced by one or more @@ -1726,20 +1712,15 @@ static void shrink_zones(int priority, struct zonelist *zonelist, if (scanning_global_lru(sc)) { if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; - note_zone_scanning_priority(zone, priority); - if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ sc->all_unreclaimable = 0; - } else { + } else /* * Ignore cpuset limitation here. We just want to reduce * # of used pages by us regardless of memory shortage. */ sc->all_unreclaimable = 0; - mem_cgroup_note_reclaim_priority(sc->mem_cgroup, - priority); - } shrink_zone(priority, zone, sc); } @@ -1845,17 +1826,11 @@ out: if (priority < 0) priority = 0; - if (scanning_global_lru(sc)) { - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { - + if (scanning_global_lru(sc)) + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; - zone->prev_priority = priority; - } - } else - mem_cgroup_record_reclaim_priority(sc->mem_cgroup, priority); - delayacct_freepages_end(); return ret; @@ -2008,22 +1983,12 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order) .mem_cgroup = NULL, .isolate_pages = isolate_pages_global, }; - /* - * temp_priority is used to remember the scanning priority at which - * this zone was successfully refilled to - * free_pages == high_wmark_pages(zone). - */ - int temp_priority[MAX_NR_ZONES]; - loop_again: total_scanned = 0; sc.nr_reclaimed = 0; sc.may_writepage = !laptop_mode; count_vm_event(PAGEOUTRUN); - for (i = 0; i < pgdat->nr_zones; i++) - temp_priority[i] = DEF_PRIORITY; - for (priority = DEF_PRIORITY; priority >= 0; priority--) { int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long lru_pages = 0; @@ -2091,9 +2056,7 @@ loop_again: if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; - temp_priority[i] = priority; sc.nr_scanned = 0; - note_zone_scanning_priority(zone, priority); nid = pgdat->node_id; zid = zone_idx(zone); @@ -2166,16 +2129,6 @@ loop_again: break; } out: - /* - * Note within each zone the priority level at which this zone was - * brought into a happy state. So that the next thread which scans this - * zone will start out at that priority level. - */ - for (i = 0; i < pgdat->nr_zones; i++) { - struct zone *zone = pgdat->node_zones + i; - - zone->prev_priority = temp_priority[i]; - } if (!all_zones_ok) { cond_resched(); @@ -2593,7 +2546,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) */ priority = ZONE_RECLAIM_PRIORITY; do { - note_zone_scanning_priority(zone, priority); shrink_zone(priority, zone, &sc); priority--; } while (priority >= 0 && sc.nr_reclaimed < nr_pages); diff --git a/mm/vmstat.c b/mm/vmstat.c index fa12ea3..2db0a0f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -761,11 +761,9 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, } seq_printf(m, "\n all_unreclaimable: %u" - "\n prev_priority: %i" "\n start_pfn: %lu" "\n inactive_ratio: %u", zone->all_unreclaimable, - zone->prev_priority, zone->zone_start_pfn, zone->inactive_ratio); seq_putc(m, '\n'); -- 1.6.5