From 23b9da55c5b0feb484bd5e8615f4eb1ce4169453 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 29 May 2012 15:06:20 -0700 Subject: mm: vmscan: remove reclaim_mode_t There is little motiviation for reclaim_mode_t once RECLAIM_MODE_[A]SYNC and lumpy reclaim have been removed. This patch gets rid of reclaim_mode_t as well and improves the documentation about what reclaim/compaction is and when it is triggered. Signed-off-by: Mel Gorman Acked-by: Rik van Riel Acked-by: KOSAKI Motohiro Cc: Konstantin Khlebnikov Cc: Hugh Dickins Cc: Ying Han Cc: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 72 +++++++++++++++++++------------------------------------------ 1 file changed, 22 insertions(+), 50 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index e27f27d4cc19..68e5819d0f1b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -53,16 +53,6 @@ #define CREATE_TRACE_POINTS #include -/* - * reclaim_mode determines how the inactive list is shrunk - * RECLAIM_MODE_SINGLE: Reclaim only order-0 pages - * RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of - * order-0 pages and then compact the zone - */ -typedef unsigned __bitwise__ reclaim_mode_t; -#define RECLAIM_MODE_SINGLE ((__force reclaim_mode_t)0x01u) -#define RECLAIM_MODE_COMPACTION ((__force reclaim_mode_t)0x10u) - struct scan_control { /* Incremented by the number of inactive pages that were scanned */ unsigned long nr_scanned; @@ -88,12 +78,6 @@ struct scan_control { int order; - /* - * Intend to reclaim enough continuous memory rather than reclaim - * enough amount of memory. i.e, mode for high order allocation. - */ - reclaim_mode_t reclaim_mode; - /* * The memory cgroup that hit its limit and as a result is the * primary target of this reclaim invocation. @@ -356,25 +340,6 @@ out: return ret; } -static void set_reclaim_mode(int priority, struct scan_control *sc) -{ - /* - * Restrict reclaim/compaction to costly allocations or when - * under memory pressure - */ - if (COMPACTION_BUILD && sc->order && - (sc->order > PAGE_ALLOC_COSTLY_ORDER || - priority < DEF_PRIORITY - 2)) - sc->reclaim_mode = RECLAIM_MODE_COMPACTION; - else - sc->reclaim_mode = RECLAIM_MODE_SINGLE; -} - -static void reset_reclaim_mode(struct scan_control *sc) -{ - sc->reclaim_mode = RECLAIM_MODE_SINGLE; -} - static inline int is_page_cache_freeable(struct page *page) { /* @@ -497,8 +462,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping, /* synchronous write or broken a_ops? */ ClearPageReclaim(page); } - trace_mm_vmscan_writepage(page, - trace_reclaim_flags(page, sc->reclaim_mode)); + trace_mm_vmscan_writepage(page, trace_reclaim_flags(page)); inc_zone_page_state(page, NR_VMSCAN_WRITE); return PAGE_SUCCESS; } @@ -953,7 +917,6 @@ cull_mlocked: try_to_free_swap(page); unlock_page(page); putback_lru_page(page); - reset_reclaim_mode(sc); continue; activate_locked: @@ -1348,8 +1311,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, return SWAP_CLUSTER_MAX; } - set_reclaim_mode(priority, sc); - lru_add_drain(); if (!sc->may_unmap) @@ -1433,7 +1394,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, zone_idx(zone), nr_scanned, nr_reclaimed, priority, - trace_shrink_flags(file, sc->reclaim_mode)); + trace_shrink_flags(file)); return nr_reclaimed; } @@ -1512,8 +1473,6 @@ static void shrink_active_list(unsigned long nr_to_scan, lru_add_drain(); - reset_reclaim_mode(sc); - if (!sc->may_unmap) isolate_mode |= ISOLATE_UNMAPPED; if (!sc->may_writepage) @@ -1826,23 +1785,35 @@ out: } } +/* Use reclaim/compaction for costly allocs or under memory pressure */ +static bool in_reclaim_compaction(int priority, struct scan_control *sc) +{ + if (COMPACTION_BUILD && sc->order && + (sc->order > PAGE_ALLOC_COSTLY_ORDER || + priority < DEF_PRIORITY - 2)) + return true; + + return false; +} + /* - * Reclaim/compaction depends on a number of pages being freed. To avoid - * disruption to the system, a small number of order-0 pages continue to be - * rotated and reclaimed in the normal fashion. However, by the time we get - * back to the allocator and call try_to_compact_zone(), we ensure that - * there are enough free pages for it to be likely successful + * Reclaim/compaction is used for high-order allocation requests. It reclaims + * order-0 pages before compacting the zone. should_continue_reclaim() returns + * true if more pages should be reclaimed such that when the page allocator + * calls try_to_compact_zone() that it will have enough free pages to succeed. + * It will give up earlier than that if there is difficulty reclaiming pages. */ static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz, unsigned long nr_reclaimed, unsigned long nr_scanned, + int priority, struct scan_control *sc) { unsigned long pages_for_compaction; unsigned long inactive_lru_pages; /* If not in reclaim/compaction mode, stop */ - if (!(sc->reclaim_mode & RECLAIM_MODE_COMPACTION)) + if (!in_reclaim_compaction(priority, sc)) return false; /* Consider stopping depending on scan and reclaim activity */ @@ -1944,7 +1915,8 @@ restart: /* reclaim/compaction might need reclaim to continue */ if (should_continue_reclaim(mz, nr_reclaimed, - sc->nr_scanned - nr_scanned, sc)) + sc->nr_scanned - nr_scanned, + priority, sc)) goto restart; throttle_vm_writeout(sc->gfp_mask); -- cgit v1.2.3-59-g8ed1b