diff options
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 328 |
1 files changed, 157 insertions, 171 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 06b198fa9ab..7a92e418a18 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -16,30 +16,11 @@ #include <linux/sysfs.h> #include "internal.h" +#if defined CONFIG_COMPACTION || defined CONFIG_CMA + #define CREATE_TRACE_POINTS #include <trace/events/compaction.h> -/* - * compact_control is used to track pages being migrated and the free pages - * they are being migrated to during memory compaction. The free_pfn starts - * at the end of a zone and migrate_pfn begins at the start. Movable pages - * are moved to the end of a zone during a compaction run and the run - * completes when free_pfn <= migrate_pfn - */ -struct compact_control { - struct list_head freepages; /* List of free pages to migrate to */ - struct list_head migratepages; /* List of pages being migrated */ - unsigned long nr_freepages; /* Number of isolated free pages */ - unsigned long nr_migratepages; /* Number of pages to migrate */ - unsigned long free_pfn; /* isolate_freepages search base */ - unsigned long migrate_pfn; /* isolate_migratepages search base */ - bool sync; /* Synchronous migration */ - - int order; /* order a direct compactor needs */ - int migratetype; /* MOVABLE, RECLAIMABLE etc */ - struct zone *zone; -}; - static unsigned long release_freepages(struct list_head *freelist) { struct page *page, *next; @@ -54,6 +35,16 @@ static unsigned long release_freepages(struct list_head *freelist) return count; } +static void map_pages(struct list_head *list) +{ + struct page *page; + + list_for_each_entry(page, list, lru) { + arch_alloc_page(page, 0); + kernel_map_pages(page, 1, 1); + } +} + /* * Isolate free pages onto a private freelist. Caller must hold zone->lock. * If @strict is true, will abort returning 0 on any invalid PFNs or non-free @@ -122,7 +113,7 @@ static unsigned long isolate_freepages_block(unsigned long blockpfn, * (which may be greater then end_pfn if end fell in a middle of * a free page). */ -static unsigned long +unsigned long isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn) { unsigned long isolated, pfn, block_end_pfn, flags; @@ -176,127 +167,6 @@ isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn) return pfn; } -/* Returns true if the page is within a block suitable for migration to */ -static bool suitable_migration_target(struct page *page) -{ - - int migratetype = get_pageblock_migratetype(page); - - /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */ - if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE) - return false; - - /* If the page is a large free page, then allow migration */ - if (PageBuddy(page) && page_order(page) >= pageblock_order) - return true; - - /* If the block is MIGRATE_MOVABLE, allow migration */ - if (migratetype == MIGRATE_MOVABLE) - return true; - - /* Otherwise skip the block */ - return false; -} - -static void map_pages(struct list_head *list) -{ - struct page *page; - - list_for_each_entry(page, list, lru) { - arch_alloc_page(page, 0); - kernel_map_pages(page, 1, 1); - } -} - -/* - * Based on information in the current compact_control, find blocks - * suitable for isolating free pages from and then isolate them. - */ -static void isolate_freepages(struct zone *zone, - struct compact_control *cc) -{ - struct page *page; - unsigned long high_pfn, low_pfn, pfn, zone_end_pfn, end_pfn; - unsigned long flags; - int nr_freepages = cc->nr_freepages; - struct list_head *freelist = &cc->freepages; - - /* - * Initialise the free scanner. The starting point is where we last - * scanned from (or the end of the zone if starting). The low point - * is the end of the pageblock the migration scanner is using. - */ - pfn = cc->free_pfn; - low_pfn = cc->migrate_pfn + pageblock_nr_pages; - - /* - * Take care that if the migration scanner is at the end of the zone - * that the free scanner does not accidentally move to the next zone - * in the next isolation cycle. - */ - high_pfn = min(low_pfn, pfn); - - zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; - - /* - * Isolate free pages until enough are available to migrate the - * pages on cc->migratepages. We stop searching if the migrate - * and free page scanners meet or enough free pages are isolated. - */ - for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; - pfn -= pageblock_nr_pages) { - unsigned long isolated; - - if (!pfn_valid(pfn)) - continue; - - /* - * Check for overlapping nodes/zones. It's possible on some - * configurations to have a setup like - * node0 node1 node0 - * i.e. it's possible that all pages within a zones range of - * pages do not belong to a single zone. - */ - page = pfn_to_page(pfn); - if (page_zone(page) != zone) - continue; - - /* Check the block is suitable for migration */ - if (!suitable_migration_target(page)) - continue; - - /* - * Found a block suitable for isolating free pages from. Now - * we disabled interrupts, double check things are ok and - * isolate the pages. This is to minimise the time IRQs - * are disabled - */ - isolated = 0; - spin_lock_irqsave(&zone->lock, flags); - if (suitable_migration_target(page)) { - end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn); - isolated = isolate_freepages_block(pfn, end_pfn, - freelist, false); - nr_freepages += isolated; - } - spin_unlock_irqrestore(&zone->lock, flags); - - /* - * Record the highest PFN we isolated pages from. When next - * looking for free pages, the search will restart here as - * page migration may have returned some pages to the allocator - */ - if (isolated) - high_pfn = max(high_pfn, pfn); - } - - /* split_free_page does not map the pages */ - map_pages(freelist); - - cc->free_pfn = high_pfn; - cc->nr_freepages = nr_freepages; -} - /* Update the number of anon and file isolated pages in the zone */ static void acct_isolated(struct zone *zone, struct compact_control *cc) { @@ -325,13 +195,6 @@ static bool too_many_isolated(struct zone *zone) return isolated > (inactive + active) / 2; } -/* possible outcome of isolate_migratepages */ -typedef enum { - ISOLATE_ABORT, /* Abort compaction now */ - ISOLATE_NONE, /* No pages isolated, continue scanning */ - ISOLATE_SUCCESS, /* Pages isolated, migrate */ -} isolate_migrate_t; - /** * isolate_migratepages_range() - isolate all migrate-able pages in range. * @zone: Zone pages are in. @@ -351,7 +214,7 @@ typedef enum { * does not modify any cc's fields, in particular it does not modify * (or read for that matter) cc->migrate_pfn. */ -static unsigned long +unsigned long isolate_migratepages_range(struct zone *zone, struct compact_control *cc, unsigned long low_pfn, unsigned long end_pfn) { @@ -487,35 +350,118 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, return low_pfn; } +#endif /* CONFIG_COMPACTION || CONFIG_CMA */ +#ifdef CONFIG_COMPACTION + +/* Returns true if the page is within a block suitable for migration to */ +static bool suitable_migration_target(struct page *page) +{ + + int migratetype = get_pageblock_migratetype(page); + + /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */ + if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE) + return false; + + /* If the page is a large free page, then allow migration */ + if (PageBuddy(page) && page_order(page) >= pageblock_order) + return true; + + /* If the block is MIGRATE_MOVABLE, allow migration */ + if (migratetype == MIGRATE_MOVABLE) + return true; + + /* Otherwise skip the block */ + return false; +} + /* - * Isolate all pages that can be migrated from the block pointed to by - * the migrate scanner within compact_control. + * Based on information in the current compact_control, find blocks + * suitable for isolating free pages from and then isolate them. */ -static isolate_migrate_t isolate_migratepages(struct zone *zone, - struct compact_control *cc) +static void isolate_freepages(struct zone *zone, + struct compact_control *cc) { - unsigned long low_pfn, end_pfn; + struct page *page; + unsigned long high_pfn, low_pfn, pfn, zone_end_pfn, end_pfn; + unsigned long flags; + int nr_freepages = cc->nr_freepages; + struct list_head *freelist = &cc->freepages; - /* Do not scan outside zone boundaries */ - low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn); + /* + * Initialise the free scanner. The starting point is where we last + * scanned from (or the end of the zone if starting). The low point + * is the end of the pageblock the migration scanner is using. + */ + pfn = cc->free_pfn; + low_pfn = cc->migrate_pfn + pageblock_nr_pages; - /* Only scan within a pageblock boundary */ - end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages); + /* + * Take care that if the migration scanner is at the end of the zone + * that the free scanner does not accidentally move to the next zone + * in the next isolation cycle. + */ + high_pfn = min(low_pfn, pfn); - /* Do not cross the free scanner or scan within a memory hole */ - if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) { - cc->migrate_pfn = end_pfn; - return ISOLATE_NONE; - } + zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; - /* Perform the isolation */ - low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn); - if (!low_pfn) - return ISOLATE_ABORT; + /* + * Isolate free pages until enough are available to migrate the + * pages on cc->migratepages. We stop searching if the migrate + * and free page scanners meet or enough free pages are isolated. + */ + for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; + pfn -= pageblock_nr_pages) { + unsigned long isolated; - cc->migrate_pfn = low_pfn; + if (!pfn_valid(pfn)) + continue; - return ISOLATE_SUCCESS; + /* + * Check for overlapping nodes/zones. It's possible on some + * configurations to have a setup like + * node0 node1 node0 + * i.e. it's possible that all pages within a zones range of + * pages do not belong to a single zone. + */ + page = pfn_to_page(pfn); + if (page_zone(page) != zone) + continue; + + /* Check the block is suitable for migration */ + if (!suitable_migration_target(page)) + continue; + + /* + * Found a block suitable for isolating free pages from. Now + * we disabled interrupts, double check things are ok and + * isolate the pages. This is to minimise the time IRQs + * are disabled + */ + isolated = 0; + spin_lock_irqsave(&zone->lock, flags); + if (suitable_migration_target(page)) { + end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn); + isolated = isolate_freepages_block(pfn, end_pfn, + freelist, false); + nr_freepages += isolated; + } + spin_unlock_irqrestore(&zone->lock, flags); + + /* + * Record the highest PFN we isolated pages from. When next + * looking for free pages, the search will restart here as + * page migration may have returned some pages to the allocator + */ + if (isolated) + high_pfn = max(high_pfn, pfn); + } + + /* split_free_page does not map the pages */ + map_pages(freelist); + + cc->free_pfn = high_pfn; + cc->nr_freepages = nr_freepages; } /* @@ -564,6 +510,44 @@ static void update_nr_listpages(struct compact_control *cc) cc->nr_freepages = nr_freepages; } +/* possible outcome of isolate_migratepages */ +typedef enum { + ISOLATE_ABORT, /* Abort compaction now */ + ISOLATE_NONE, /* No pages isolated, continue scanning */ + ISOLATE_SUCCESS, /* Pages isolated, migrate */ +} isolate_migrate_t; + +/* + * Isolate all pages that can be migrated from the block pointed to by + * the migrate scanner within compact_control. + */ +static isolate_migrate_t isolate_migratepages(struct zone *zone, + struct compact_control *cc) +{ + unsigned long low_pfn, end_pfn; + + /* Do not scan outside zone boundaries */ + low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn); + + /* Only scan within a pageblock boundary */ + end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages); + + /* Do not cross the free scanner or scan within a memory hole */ + if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) { + cc->migrate_pfn = end_pfn; + return ISOLATE_NONE; + } + + /* Perform the isolation */ + low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn); + if (!low_pfn) + return ISOLATE_ABORT; + + cc->migrate_pfn = low_pfn; + + return ISOLATE_SUCCESS; +} + static int compact_finished(struct zone *zone, struct compact_control *cc) { @@ -910,3 +894,5 @@ void compaction_unregister_node(struct node *node) return device_remove_file(&node->dev, &dev_attr_compact); } #endif /* CONFIG_SYSFS && CONFIG_NUMA */ + +#endif /* CONFIG_COMPACTION */ |