From 258401a60c4df39332f30ef57afbc6dbf29a7e84 Mon Sep 17 00:00:00 2001 From: Zlatko Calusic Date: Fri, 22 Feb 2013 16:34:06 -0800 Subject: [PATCH] mm: don't wait on congested zones in balance_pgdat() From: Zlatko Calusic Commit 92df3a723f84 ("mm: vmscan: throttle reclaim if encountering too many dirty pages under writeback") introduced waiting on congested zones based on a sane algorithm in shrink_inactive_list(). What this means is that there's no more need for throttling and additional heuristics in balance_pgdat(). So, let's remove it and tidy up the code. Signed-off-by: Zlatko Calusic Cc: Mel Gorman Cc: Minchan Kim Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vm_event_item.h | 1 - mm/vmscan.c | 29 +---------------------------- mm/vmstat.c | 1 - 3 files changed, 1 insertion(+), 30 deletions(-) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index fce0a2799d43..bd6cf61142be 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -36,7 +36,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, #endif PGINODESTEAL, SLABS_SCANNED, KSWAPD_INODESTEAL, KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY, - KSWAPD_SKIP_CONGESTION_WAIT, PAGEOUTRUN, ALLOCSTALL, PGROTATED, #ifdef CONFIG_NUMA_BALANCING NUMA_PTE_UPDATES, diff --git a/mm/vmscan.c b/mm/vmscan.c index 8fde2fc223d9..b93968b71dc6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2617,7 +2617,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, int *classzone_idx) { bool pgdat_is_balanced = false; - struct zone *unbalanced_zone; int i; int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long total_scanned; @@ -2648,9 +2647,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, do { unsigned long lru_pages = 0; - int has_under_min_watermark_zone = 0; - - unbalanced_zone = NULL; /* * Scan in the highmem->dma direction for the highest @@ -2790,17 +2786,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, continue; } - if (!zone_balanced(zone, testorder, 0, end_zone)) { - unbalanced_zone = zone; - /* - * We are still under min water mark. This - * means that we have a GFP_ATOMIC allocation - * failure risk. Hurry up! - */ - if (!zone_watermark_ok_safe(zone, order, - min_wmark_pages(zone), end_zone, 0)) - has_under_min_watermark_zone = 1; - } else { + if (zone_balanced(zone, testorder, 0, end_zone)) /* * If a zone reaches its high watermark, * consider it to be no longer congested. It's @@ -2809,8 +2795,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, * speculatively avoid congestion waits */ zone_clear_flag(zone, ZONE_CONGESTED); - } - } /* @@ -2827,17 +2811,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, break; /* kswapd: all done */ } - /* - * OK, kswapd is getting into trouble. Take a nap, then take - * another pass across the zones. - */ - if (total_scanned && (sc.priority < DEF_PRIORITY - 2)) { - if (has_under_min_watermark_zone) - count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT); - else if (unbalanced_zone) - wait_iff_congested(unbalanced_zone, BLK_RW_ASYNC, HZ/10); - } - /* * We do this so kswapd doesn't build up large priorities for * example when it is freeing in parallel with allocators. It diff --git a/mm/vmstat.c b/mm/vmstat.c index c9d1f68120cd..57f02fd1768b 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -770,7 +770,6 @@ const char * const vmstat_text[] = { "kswapd_inodesteal", "kswapd_low_wmark_hit_quickly", "kswapd_high_wmark_hit_quickly", - "kswapd_skip_congestion_wait", "pageoutrun", "allocstall",