From ee64fc9354e515a79c7232cfde65c88ec627308b Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 13 Jan 2011 15:45:55 -0800 Subject: mm: vmscan: convert lumpy_mode into a bitmask Currently lumpy_mode is an enum and determines if lumpy reclaim is off, syncronous or asyncronous. In preparation for using compaction instead of lumpy reclaim, this patch converts the flags into a bitmap. Signed-off-by: Mel Gorman Cc: Andrea Arcangeli Cc: KOSAKI Motohiro Cc: Rik van Riel Cc: Johannes Weiner Cc: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index cacdf6684971..3464312bde07 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -51,11 +51,20 @@ #define CREATE_TRACE_POINTS #include -enum lumpy_mode { - LUMPY_MODE_NONE, - LUMPY_MODE_ASYNC, - LUMPY_MODE_SYNC, -}; +/* + * lumpy_mode determines how the inactive list is shrunk + * LUMPY_MODE_SINGLE: Reclaim only order-0 pages + * LUMPY_MODE_ASYNC: Do not block + * LUMPY_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback + * LUMPY_MODE_CONTIGRECLAIM: For high-order allocations, take a reference + * page from the LRU and reclaim all pages within a + * naturally aligned range + */ +typedef unsigned __bitwise__ lumpy_mode; +#define LUMPY_MODE_SINGLE ((__force lumpy_mode)0x01u) +#define LUMPY_MODE_ASYNC ((__force lumpy_mode)0x02u) +#define LUMPY_MODE_SYNC ((__force lumpy_mode)0x04u) +#define LUMPY_MODE_CONTIGRECLAIM ((__force lumpy_mode)0x08u) struct scan_control { /* Incremented by the number of inactive pages that were scanned */ @@ -88,7 +97,7 @@ struct scan_control { * Intend to reclaim enough continuous memory rather than reclaim * enough amount of memory. i.e, mode for high order allocation. */ - enum lumpy_mode lumpy_reclaim_mode; + lumpy_mode lumpy_reclaim_mode; /* Which cgroup do we reclaim from */ struct mem_cgroup *mem_cgroup; @@ -274,13 +283,13 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask, static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc, bool sync) { - enum lumpy_mode mode = sync ? LUMPY_MODE_SYNC : LUMPY_MODE_ASYNC; + lumpy_mode syncmode = sync ? LUMPY_MODE_SYNC : LUMPY_MODE_ASYNC; /* * Some reclaim have alredy been failed. No worth to try synchronous * lumpy reclaim. */ - if (sync && sc->lumpy_reclaim_mode == LUMPY_MODE_NONE) + if (sync && sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE) return; /* @@ -288,17 +297,18 @@ static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc, * trouble getting a small set of contiguous pages, we * will reclaim both active and inactive pages. */ + sc->lumpy_reclaim_mode = LUMPY_MODE_CONTIGRECLAIM; if (sc->order > PAGE_ALLOC_COSTLY_ORDER) - sc->lumpy_reclaim_mode = mode; + sc->lumpy_reclaim_mode |= syncmode; else if (sc->order && priority < DEF_PRIORITY - 2) - sc->lumpy_reclaim_mode = mode; + sc->lumpy_reclaim_mode |= syncmode; else - sc->lumpy_reclaim_mode = LUMPY_MODE_NONE; + sc->lumpy_reclaim_mode = LUMPY_MODE_SINGLE | LUMPY_MODE_ASYNC; } static void disable_lumpy_reclaim_mode(struct scan_control *sc) { - sc->lumpy_reclaim_mode = LUMPY_MODE_NONE; + sc->lumpy_reclaim_mode = LUMPY_MODE_SINGLE | LUMPY_MODE_ASYNC; } static inline int is_page_cache_freeable(struct page *page) @@ -429,7 +439,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping, * first attempt to free a range of pages fails. */ if (PageWriteback(page) && - sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC) + (sc->lumpy_reclaim_mode & LUMPY_MODE_SYNC)) wait_on_page_writeback(page); if (!PageWriteback(page)) { @@ -622,7 +632,7 @@ static enum page_references page_check_references(struct page *page, referenced_page = TestClearPageReferenced(page); /* Lumpy reclaim - ignore references */ - if (sc->lumpy_reclaim_mode != LUMPY_MODE_NONE) + if (sc->lumpy_reclaim_mode & LUMPY_MODE_CONTIGRECLAIM) return PAGEREF_RECLAIM; /* @@ -739,7 +749,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, * for any page for which writeback has already * started. */ - if (sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC && + if ((sc->lumpy_reclaim_mode & LUMPY_MODE_SYNC) && may_enter_fs) wait_on_page_writeback(page); else { @@ -1324,7 +1334,7 @@ static inline bool should_reclaim_stall(unsigned long nr_taken, return false; /* Only stall on lumpy reclaim */ - if (sc->lumpy_reclaim_mode == LUMPY_MODE_NONE) + if (sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE) return false; /* If we have relaimed everything on the isolated list, no stall */ @@ -1375,7 +1385,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, if (scanning_global_lru(sc)) { nr_taken = isolate_pages_global(nr_to_scan, &page_list, &nr_scanned, sc->order, - sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ? + sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE ? ISOLATE_INACTIVE : ISOLATE_BOTH, zone, 0, file); zone->pages_scanned += nr_scanned; @@ -1388,7 +1398,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, } else { nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list, &nr_scanned, sc->order, - sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ? + sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE ? ISOLATE_INACTIVE : ISOLATE_BOTH, zone, sc->mem_cgroup, 0, file); -- cgit v1.2.3