From 22fba33545b731408deab6e96b6e231ee05fd10b Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 14 Dec 2009 17:59:10 -0800 Subject: [PATCH] vmscan: separate sc.swap_cluster_max and sc.nr_max_reclaim Currently, sc.scap_cluster_max has double meanings. 1) reclaim batch size as isolate_lru_pages()'s argument 2) reclaim baling out thresolds The two meanings pretty unrelated. Thus, Let's separate it. this patch doesn't change any behavior. Signed-off-by: KOSAKI Motohiro Reviewed-by: Rik van Riel Reviewed-by: Minchan Kim Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index cb69f717799f..7b0d5c784c7e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -55,6 +55,9 @@ struct scan_control { /* Number of pages freed so far during a call to shrink_zones() */ unsigned long nr_reclaimed; + /* How many pages shrink_list() should reclaim */ + unsigned long nr_to_reclaim; + /* This context's GFP mask */ gfp_t gfp_mask; @@ -1595,6 +1598,7 @@ static void shrink_zone(int priority, struct zone *zone, enum lru_list l; unsigned long nr_reclaimed = sc->nr_reclaimed; unsigned long swap_cluster_max = sc->swap_cluster_max; + unsigned long nr_to_reclaim = sc->nr_to_reclaim; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); int noswap = 0; @@ -1639,8 +1643,7 @@ static void shrink_zone(int priority, struct zone *zone, * with multiple processes reclaiming pages, the total * freeing target can get unreasonably large. */ - if (nr_reclaimed > swap_cluster_max && - priority < DEF_PRIORITY && !current_is_kswapd()) + if (nr_reclaimed > nr_to_reclaim && priority < DEF_PRIORITY) break; } @@ -1738,6 +1741,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct zoneref *z; struct zone *zone; enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); + unsigned long writeback_threshold; delayacct_freepages_start(); @@ -1773,7 +1777,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, } } total_scanned += sc->nr_scanned; - if (sc->nr_reclaimed >= sc->swap_cluster_max) { + if (sc->nr_reclaimed >= sc->nr_to_reclaim) { ret = sc->nr_reclaimed; goto out; } @@ -1785,8 +1789,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, * that's undesirable in laptop mode, where we *want* lumpy * writeout. So in laptop mode, write out the whole world. */ - if (total_scanned > sc->swap_cluster_max + - sc->swap_cluster_max / 2) { + writeback_threshold = sc->nr_to_reclaim + sc->nr_to_reclaim / 2; + if (total_scanned > writeback_threshold) { wakeup_flusher_threads(laptop_mode ? 0 : total_scanned); sc->may_writepage = 1; } @@ -1832,6 +1836,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, .gfp_mask = gfp_mask, .may_writepage = !laptop_mode, .swap_cluster_max = SWAP_CLUSTER_MAX, + .nr_to_reclaim = SWAP_CLUSTER_MAX, .may_unmap = 1, .may_swap = 1, .swappiness = vm_swappiness, @@ -1890,6 +1895,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont, .may_unmap = 1, .may_swap = !noswap, .swap_cluster_max = SWAP_CLUSTER_MAX, + .nr_to_reclaim = SWAP_CLUSTER_MAX, .swappiness = swappiness, .order = 0, .mem_cgroup = mem_cont, @@ -1961,6 +1967,11 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order) .may_unmap = 1, .may_swap = 1, .swap_cluster_max = SWAP_CLUSTER_MAX, + /* + * kswapd doesn't want to be bailed out while reclaim. because + * we want to put equal scanning pressure on each zone. + */ + .nr_to_reclaim = ULONG_MAX, .swappiness = vm_swappiness, .order = order, .mem_cgroup = NULL, @@ -2630,7 +2641,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP), .may_swap = 1, .swap_cluster_max = max_t(unsigned long, nr_pages, - SWAP_CLUSTER_MAX), + SWAP_CLUSTER_MAX), + .nr_to_reclaim = max_t(unsigned long, nr_pages, + SWAP_CLUSTER_MAX), .gfp_mask = gfp_mask, .swappiness = vm_swappiness, .order = order, -- 2.30.2