From 49ea7eb65e7c5060807fb9312b1ad4c3eab82e2c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 31 Oct 2011 17:07:59 -0700 Subject: [PATCH] mm: vmscan: immediately reclaim end-of-LRU dirty pages when writeback completes When direct reclaim encounters a dirty page, it gets recycled around the LRU for another cycle. This patch marks the page PageReclaim similar to deactivate_page() so that the page gets reclaimed almost immediately after the page gets cleaned. This is to avoid reclaiming clean pages that are younger than a dirty page encountered at the end of the LRU that might have been something like a use-once page. Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Cc: Dave Chinner Cc: Christoph Hellwig Cc: Wu Fengguang Cc: Jan Kara Cc: Minchan Kim Cc: Rik van Riel Cc: Mel Gorman Cc: Alex Elder Cc: Theodore Ts'o Cc: Chris Mason Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 2 +- mm/vmscan.c | 10 +++++++++- mm/vmstat.c | 2 +- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 2c41b2c1943b..188cb2ffe8db 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -100,7 +100,7 @@ enum zone_stat_item { NR_UNSTABLE_NFS, /* NFS unstable pages */ NR_BOUNCE, NR_VMSCAN_WRITE, - NR_VMSCAN_WRITE_SKIP, + NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ diff --git a/mm/vmscan.c b/mm/vmscan.c index 7b0573f33a27..a297603d35bc 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -866,7 +866,15 @@ static unsigned long shrink_page_list(struct list_head *page_list, */ if (page_is_file_cache(page) && (!current_is_kswapd() || priority >= DEF_PRIORITY - 2)) { - inc_zone_page_state(page, NR_VMSCAN_WRITE_SKIP); + /* + * Immediately reclaim when written back. + * Similar in principal to deactivate_page() + * except we already have the page isolated + * and know it's dirty + */ + inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE); + SetPageReclaim(page); + goto keep_locked; } diff --git a/mm/vmstat.c b/mm/vmstat.c index 210bd8ff3a6e..56e529a40517 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -702,7 +702,7 @@ const char * const vmstat_text[] = { "nr_unstable", "nr_bounce", "nr_vmscan_write", - "nr_vmscan_write_skip", + "nr_vmscan_immediate_reclaim", "nr_writeback_temp", "nr_isolated_anon", "nr_isolated_file", -- 2.39.2