diff options
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 571 |
1 files changed, 315 insertions, 256 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 9eef55838fc..21bf292b642 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -14,8 +14,25 @@ #include <linux/backing-dev.h> #include <linux/sysctl.h> #include <linux/sysfs.h> +#include <linux/balloon_compaction.h> +#include <linux/page-isolation.h> #include "internal.h" +#ifdef CONFIG_COMPACTION +static inline void count_compact_event(enum vm_event_item item) +{ + count_vm_event(item); +} + +static inline void count_compact_events(enum vm_event_item item, long delta) +{ + count_vm_events(item, delta); +} +#else +#define count_compact_event(item) do { } while (0) +#define count_compact_events(item, delta) do { } while (0) +#endif + #if defined CONFIG_COMPACTION || defined CONFIG_CMA #define CREATE_TRACE_POINTS @@ -69,10 +86,11 @@ static inline bool isolation_suitable(struct compact_control *cc, static void __reset_isolation_suitable(struct zone *zone) { unsigned long start_pfn = zone->zone_start_pfn; - unsigned long end_pfn = zone->zone_start_pfn + zone->spanned_pages; + unsigned long end_pfn = zone_end_pfn(zone); unsigned long pfn; - zone->compact_cached_migrate_pfn = start_pfn; + zone->compact_cached_migrate_pfn[0] = start_pfn; + zone->compact_cached_migrate_pfn[1] = start_pfn; zone->compact_cached_free_pfn = end_pfn; zone->compact_blockskip_flush = false; @@ -114,26 +132,43 @@ void reset_isolation_suitable(pg_data_t *pgdat) */ static void update_pageblock_skip(struct compact_control *cc, struct page *page, unsigned long nr_isolated, - bool migrate_scanner) + bool set_unsuitable, bool migrate_scanner) { struct zone *zone = cc->zone; + unsigned long pfn; + + if (cc->ignore_skip_hint) + return; + if (!page) return; - if (!nr_isolated) { - unsigned long pfn = page_to_pfn(page); + if (nr_isolated) + return; + + /* + * Only skip pageblocks when all forms of compaction will be known to + * fail in the near future. + */ + if (set_unsuitable) set_pageblock_skip(page); - /* Update where compaction should restart */ - if (migrate_scanner) { - if (!cc->finished_update_migrate && - pfn > zone->compact_cached_migrate_pfn) - zone->compact_cached_migrate_pfn = pfn; - } else { - if (!cc->finished_update_free && - pfn < zone->compact_cached_free_pfn) - zone->compact_cached_free_pfn = pfn; - } + pfn = page_to_pfn(page); + + /* Update where async and sync compaction should restart */ + if (migrate_scanner) { + if (cc->finished_update_migrate) + return; + if (pfn > zone->compact_cached_migrate_pfn[0]) + zone->compact_cached_migrate_pfn[0] = pfn; + if (cc->mode != MIGRATE_ASYNC && + pfn > zone->compact_cached_migrate_pfn[1]) + zone->compact_cached_migrate_pfn[1] = pfn; + } else { + if (cc->finished_update_free) + return; + if (pfn < zone->compact_cached_free_pfn) + zone->compact_cached_free_pfn = pfn; } } #else @@ -145,7 +180,7 @@ static inline bool isolation_suitable(struct compact_control *cc, static void update_pageblock_skip(struct compact_control *cc, struct page *page, unsigned long nr_isolated, - bool migrate_scanner) + bool set_unsuitable, bool migrate_scanner) { } #endif /* CONFIG_COMPACTION */ @@ -174,7 +209,7 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, } /* async aborts if taking too long or contended */ - if (!cc->sync) { + if (cc->mode == MIGRATE_ASYNC) { cc->contended = true; return false; } @@ -187,92 +222,49 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, return true; } -static inline bool compact_trylock_irqsave(spinlock_t *lock, - unsigned long *flags, struct compact_control *cc) +/* + * Aside from avoiding lock contention, compaction also periodically checks + * need_resched() and either schedules in sync compaction or aborts async + * compaction. This is similar to what compact_checklock_irqsave() does, but + * is used where no lock is concerned. + * + * Returns false when no scheduling was needed, or sync compaction scheduled. + * Returns true when async compaction should abort. + */ +static inline bool compact_should_abort(struct compact_control *cc) { - return compact_checklock_irqsave(lock, flags, false, cc); + /* async compaction aborts if contended */ + if (need_resched()) { + if (cc->mode == MIGRATE_ASYNC) { + cc->contended = true; + return true; + } + + cond_resched(); + } + + return false; } /* 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 the page is a large free page, then disallow migration */ if (PageBuddy(page) && page_order(page) >= pageblock_order) - return true; + return false; /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */ - if (migrate_async_suitable(migratetype)) + if (migrate_async_suitable(get_pageblock_migratetype(page))) return true; /* Otherwise skip the block */ return false; } -static void compact_capture_page(struct compact_control *cc) -{ - unsigned long flags; - int mtype, mtype_low, mtype_high; - - if (!cc->page || *cc->page) - return; - - /* - * For MIGRATE_MOVABLE allocations we capture a suitable page ASAP - * regardless of the migratetype of the freelist is is captured from. - * This is fine because the order for a high-order MIGRATE_MOVABLE - * allocation is typically at least a pageblock size and overall - * fragmentation is not impaired. Other allocation types must - * capture pages from their own migratelist because otherwise they - * could pollute other pageblocks like MIGRATE_MOVABLE with - * difficult to move pages and making fragmentation worse overall. - */ - if (cc->migratetype == MIGRATE_MOVABLE) { - mtype_low = 0; - mtype_high = MIGRATE_PCPTYPES; - } else { - mtype_low = cc->migratetype; - mtype_high = cc->migratetype + 1; - } - - /* Speculatively examine the free lists without zone lock */ - for (mtype = mtype_low; mtype < mtype_high; mtype++) { - int order; - for (order = cc->order; order < MAX_ORDER; order++) { - struct page *page; - struct free_area *area; - area = &(cc->zone->free_area[order]); - if (list_empty(&area->free_list[mtype])) - continue; - - /* Take the lock and attempt capture of the page */ - if (!compact_trylock_irqsave(&cc->zone->lock, &flags, cc)) - return; - if (!list_empty(&area->free_list[mtype])) { - page = list_entry(area->free_list[mtype].next, - struct page, lru); - if (capture_free_page(page, cc->order, mtype)) { - spin_unlock_irqrestore(&cc->zone->lock, - flags); - *cc->page = page; - return; - } - } - spin_unlock_irqrestore(&cc->zone->lock, flags); - } - } -} - /* - * 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 - * pages inside of the pageblock (even though it may still end up isolating - * some pages). + * Isolate free pages onto a private freelist. If @strict is true, will abort + * returning 0 on any invalid PFNs or non-free pages inside of the pageblock + * (even though it may still end up isolating some pages). */ static unsigned long isolate_freepages_block(struct compact_control *cc, unsigned long blockpfn, @@ -282,9 +274,9 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, { int nr_scanned = 0, total_isolated = 0; struct page *cursor, *valid_page = NULL; - unsigned long nr_strict_required = end_pfn - blockpfn; unsigned long flags; bool locked = false; + bool checked_pageblock = false; cursor = pfn_to_page(blockpfn); @@ -295,11 +287,12 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, nr_scanned++; if (!pfn_valid_within(blockpfn)) - continue; + goto isolate_fail; + if (!valid_page) valid_page = page; if (!PageBuddy(page)) - continue; + goto isolate_fail; /* * The zone lock must be held to isolate freepages. @@ -315,17 +308,23 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, break; /* Recheck this is a suitable migration target under lock */ - if (!strict && !suitable_migration_target(page)) - break; + if (!strict && !checked_pageblock) { + /* + * We need to check suitability of pageblock only once + * and this isolate_freepages_block() is called with + * pageblock range, so just check once is sufficient. + */ + checked_pageblock = true; + if (!suitable_migration_target(page)) + break; + } /* Recheck this is a buddy page under lock */ if (!PageBuddy(page)) - continue; + goto isolate_fail; /* Found a free page, break it into order-0 pages */ isolated = split_free_page(page); - if (!isolated && strict) - break; total_isolated += isolated; for (i = 0; i < isolated; i++) { list_add(&page->lru, freelist); @@ -336,7 +335,15 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, if (isolated) { blockpfn += isolated - 1; cursor += isolated - 1; + continue; } + +isolate_fail: + if (strict) + break; + else + continue; + } trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated); @@ -346,7 +353,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, * pages requested were isolated. If there were any failures, 0 is * returned and CMA will fail. */ - if (strict && nr_strict_required > total_isolated) + if (strict && blockpfn < end_pfn) total_isolated = 0; if (locked) @@ -354,8 +361,12 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, /* Update the pageblock-skip if the whole pageblock was scanned */ if (blockpfn == end_pfn) - update_pageblock_skip(cc, valid_page, total_isolated, false); + update_pageblock_skip(cc, valid_page, total_isolated, true, + false); + count_compact_events(COMPACTFREE_SCANNED, nr_scanned); + if (total_isolated) + count_compact_events(COMPACTISOLATED, total_isolated); return total_isolated; } @@ -482,11 +493,14 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, unsigned long last_pageblock_nr = 0, pageblock_nr; unsigned long nr_scanned = 0, nr_isolated = 0; struct list_head *migratelist = &cc->migratepages; - isolate_mode_t mode = 0; struct lruvec *lruvec; unsigned long flags; bool locked = false; struct page *page = NULL, *valid_page = NULL; + bool set_unsuitable = true; + const isolate_mode_t mode = (cc->mode == MIGRATE_ASYNC ? + ISOLATE_ASYNC_MIGRATE : 0) | + (unevictable ? ISOLATE_UNEVICTABLE : 0); /* * Ensure that there are not too many pages isolated from the LRU @@ -495,7 +509,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, */ while (unlikely(too_many_isolated(zone))) { /* async migration should just abort */ - if (!cc->sync) + if (cc->mode == MIGRATE_ASYNC) return 0; congestion_wait(BLK_RW_ASYNC, HZ/10); @@ -504,11 +518,13 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, return 0; } + if (compact_should_abort(cc)) + return 0; + /* Time to isolate some pages for migration */ - cond_resched(); for (; low_pfn < end_pfn; low_pfn++) { /* give a chance to irqs before checking need_resched() */ - if (locked && !((low_pfn+1) % SWAP_CLUSTER_MAX)) { + if (locked && !(low_pfn % SWAP_CLUSTER_MAX)) { if (should_release_lock(&zone->lru_lock)) { spin_unlock_irqrestore(&zone->lru_lock, flags); locked = false; @@ -547,27 +563,47 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, /* If isolation recently failed, do not retry */ pageblock_nr = low_pfn >> pageblock_order; - if (!isolation_suitable(cc, page)) - goto next_pageblock; + if (last_pageblock_nr != pageblock_nr) { + int mt; - /* Skip if free */ + last_pageblock_nr = pageblock_nr; + if (!isolation_suitable(cc, page)) + goto next_pageblock; + + /* + * For async migration, also only scan in MOVABLE + * blocks. Async migration is optimistic to see if + * the minimum amount of work satisfies the allocation + */ + mt = get_pageblock_migratetype(page); + if (cc->mode == MIGRATE_ASYNC && + !migrate_async_suitable(mt)) { + set_unsuitable = false; + goto next_pageblock; + } + } + + /* + * Skip if free. page_order cannot be used without zone->lock + * as nothing prevents parallel allocations or buddy merging. + */ if (PageBuddy(page)) continue; /* - * For async migration, also only scan in MOVABLE blocks. Async - * migration is optimistic to see if the minimum amount of work - * satisfies the allocation + * Check may be lockless but that's ok as we recheck later. + * It's possible to migrate LRU pages and balloon pages + * Skip any other type of page */ - if (!cc->sync && last_pageblock_nr != pageblock_nr && - !migrate_async_suitable(get_pageblock_migratetype(page))) { - cc->finished_update_migrate = true; - goto next_pageblock; - } - - /* Check may be lockless but that's ok as we recheck later */ - if (!PageLRU(page)) + if (!PageLRU(page)) { + if (unlikely(balloon_page_movable(page))) { + if (locked && balloon_page_isolate(page)) { + /* Successfully isolated */ + goto isolate_success; + } + } continue; + } /* * PageLRU is set. lru_lock normally excludes isolation @@ -586,6 +622,15 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, continue; } + /* + * Migration will fail if an anonymous page is pinned in memory, + * so avoid taking lru_lock and isolating it unnecessarily in an + * admittedly racy check. + */ + if (!page_mapping(page) && + page_count(page) > page_mapcount(page)) + continue; + /* Check if it is ok to still hold the lock */ locked = compact_checklock_irqsave(&zone->lru_lock, &flags, locked, cc); @@ -600,23 +645,19 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, continue; } - if (!cc->sync) - mode |= ISOLATE_ASYNC_MIGRATE; - - if (unevictable) - mode |= ISOLATE_UNEVICTABLE; - lruvec = mem_cgroup_page_lruvec(page, zone); /* Try isolate the page */ if (__isolate_lru_page(page, mode) != 0) continue; - VM_BUG_ON(PageTransCompound(page)); + VM_BUG_ON_PAGE(PageTransCompound(page), page); /* Successfully isolated */ - cc->finished_update_migrate = true; del_page_from_lru_list(page, lruvec, page_lru(page)); + +isolate_success: + cc->finished_update_migrate = true; list_add(&page->lru, migratelist); cc->nr_migratepages++; nr_isolated++; @@ -630,9 +671,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, continue; next_pageblock: - low_pfn += pageblock_nr_pages; - low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1; - last_pageblock_nr = pageblock_nr; + low_pfn = ALIGN(low_pfn + 1, pageblock_nr_pages) - 1; } acct_isolated(zone, locked, cc); @@ -640,12 +679,20 @@ next_pageblock: if (locked) spin_unlock_irqrestore(&zone->lru_lock, flags); - /* Update the pageblock-skip if the whole pageblock was scanned */ + /* + * Update the pageblock-skip information and cached scanner pfn, + * if the whole pageblock was scanned without isolating any page. + */ if (low_pfn == end_pfn) - update_pageblock_skip(cc, valid_page, nr_isolated, true); + update_pageblock_skip(cc, valid_page, nr_isolated, + set_unsuitable, true); trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated); + count_compact_events(COMPACTMIGRATE_SCANNED, nr_scanned); + if (nr_isolated) + count_compact_events(COMPACTISOLATED, nr_isolated); + return low_pfn; } @@ -659,37 +706,48 @@ 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 block_start_pfn; /* start of current pageblock */ + unsigned long block_end_pfn; /* end of current pageblock */ + unsigned long low_pfn; /* lowest pfn scanner is able to scan */ 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. + * successfully isolated from, zone-cached value, or the end of the + * zone when isolating for the first time. We need this aligned to + * the pageblock boundary, because we do + * block_start_pfn -= pageblock_nr_pages in the for loop. + * For ending point, take care when isolating in last pageblock of a + * a zone which ends in the middle of a pageblock. + * The low boundary 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; + block_start_pfn = cc->free_pfn & ~(pageblock_nr_pages-1); + block_end_pfn = min(block_start_pfn + pageblock_nr_pages, + zone_end_pfn(zone)); + low_pfn = ALIGN(cc->migrate_pfn + 1, pageblock_nr_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) { + for (; block_start_pfn >= low_pfn && cc->nr_migratepages > nr_freepages; + block_end_pfn = block_start_pfn, + block_start_pfn -= pageblock_nr_pages) { unsigned long isolated; - if (!pfn_valid(pfn)) + /* + * This can iterate a massively long zone without finding any + * suitable migration targets, so periodically check if we need + * to schedule, or even abort async compaction. + */ + if (!(block_start_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages)) + && compact_should_abort(cc)) + break; + + if (!pfn_valid(block_start_pfn)) continue; /* @@ -699,7 +757,7 @@ static void isolate_freepages(struct zone *zone, * 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); + page = pfn_to_page(block_start_pfn); if (page_zone(page) != zone) continue; @@ -712,27 +770,38 @@ static void isolate_freepages(struct zone *zone, continue; /* Found a block suitable for isolating free pages from */ - isolated = 0; - end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn); - isolated = isolate_freepages_block(cc, pfn, end_pfn, - freelist, false); + cc->free_pfn = block_start_pfn; + isolated = isolate_freepages_block(cc, block_start_pfn, + block_end_pfn, freelist, false); nr_freepages += isolated; /* - * 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 + * Set a flag that we successfully isolated in this pageblock. + * In the next loop iteration, zone->compact_cached_free_pfn + * will not be updated and thus it will effectively contain the + * highest pageblock we isolated pages from. */ - if (isolated) { + if (isolated) cc->finished_update_free = true; - high_pfn = max(high_pfn, pfn); - } + + /* + * isolate_freepages_block() might have aborted due to async + * compaction being contended + */ + if (cc->contended) + break; } /* split_free_page does not map the pages */ map_pages(freelist); - cc->free_pfn = high_pfn; + /* + * If we crossed the migrate scanner, we want to keep it that way + * so that compact_finished() may detect this + */ + if (block_start_pfn < low_pfn) + cc->free_pfn = cc->migrate_pfn; + cc->nr_freepages = nr_freepages; } @@ -747,9 +816,13 @@ static struct page *compaction_alloc(struct page *migratepage, struct compact_control *cc = (struct compact_control *)data; struct page *freepage; - /* Isolate free pages if necessary */ + /* + * Isolate free pages if necessary, and if we are not aborting due to + * contention. + */ if (list_empty(&cc->freepages)) { - isolate_freepages(cc->zone, cc); + if (!cc->contended) + isolate_freepages(cc->zone, cc); if (list_empty(&cc->freepages)) return NULL; @@ -763,23 +836,16 @@ static struct page *compaction_alloc(struct page *migratepage, } /* - * We cannot control nr_migratepages and nr_freepages fully when migration is - * running as migrate_pages() has no knowledge of compact_control. When - * migration is complete, we count the number of pages on the lists by hand. + * This is a migrate-callback that "frees" freepages back to the isolated + * freelist. All pages on the freelist are from the same zone, so there is no + * special handling needed for NUMA. */ -static void update_nr_listpages(struct compact_control *cc) +static void compaction_free(struct page *page, unsigned long data) { - int nr_migratepages = 0; - int nr_freepages = 0; - struct page *page; - - list_for_each_entry(page, &cc->migratepages, lru) - nr_migratepages++; - list_for_each_entry(page, &cc->freepages, lru) - nr_freepages++; + struct compact_control *cc = (struct compact_control *)data; - cc->nr_migratepages = nr_migratepages; - cc->nr_freepages = nr_freepages; + list_add(&page->lru, &cc->freepages); + cc->nr_freepages++; } /* possible outcome of isolate_migratepages */ @@ -802,7 +868,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, 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); + end_pfn = ALIGN(low_pfn + 1, 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)) { @@ -823,13 +889,19 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, static int compact_finished(struct zone *zone, struct compact_control *cc) { + unsigned int order; unsigned long watermark; - if (fatal_signal_pending(current)) + if (cc->contended || fatal_signal_pending(current)) return COMPACT_PARTIAL; /* Compaction run completes if the migrate and free scanner meet */ if (cc->free_pfn <= cc->migrate_pfn) { + /* Let the next compaction start anew. */ + zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn; + zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn; + zone->compact_cached_free_pfn = zone_end_pfn(zone); + /* * Mark that the PG_migrate_skip information should be cleared * by kswapd when it goes to sleep. kswapd does not set the @@ -857,22 +929,16 @@ static int compact_finished(struct zone *zone, return COMPACT_CONTINUE; /* Direct compactor: Is a suitable page free? */ - if (cc->page) { - /* Was a suitable page captured? */ - if (*cc->page) + for (order = cc->order; order < MAX_ORDER; order++) { + struct free_area *area = &zone->free_area[order]; + + /* Job done if page is free of the right migratetype */ + if (!list_empty(&area->free_list[cc->migratetype])) + return COMPACT_PARTIAL; + + /* Job done if allocation would set block type */ + if (cc->order >= pageblock_order && area->nr_free) return COMPACT_PARTIAL; - } else { - unsigned int order; - for (order = cc->order; order < MAX_ORDER; order++) { - struct free_area *area = &zone->free_area[cc->order]; - /* Job done if page is free of the right migratetype */ - if (!list_empty(&area->free_list[cc->migratetype])) - return COMPACT_PARTIAL; - - /* Job done if allocation would set block type */ - if (cc->order >= pageblock_order && area->nr_free) - return COMPACT_PARTIAL; - } } return COMPACT_CONTINUE; @@ -932,7 +998,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) { int ret; unsigned long start_pfn = zone->zone_start_pfn; - unsigned long end_pfn = zone->zone_start_pfn + zone->spanned_pages; + unsigned long end_pfn = zone_end_pfn(zone); + const bool sync = cc->mode != MIGRATE_ASYNC; ret = compaction_suitable(zone, cc->order); switch (ret) { @@ -946,11 +1013,19 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) } /* + * Clear pageblock skip if there were failures recently and compaction + * is about to be retried after being deferred. kswapd does not do + * this reset as it'll reset the cached information when going to sleep. + */ + if (compaction_restarting(zone, cc->order) && !current_is_kswapd()) + __reset_isolation_suitable(zone); + + /* * Setup to move all movable pages to the end of the zone. Used cached * information on where the scanners should start but check that it * is initialised by ensuring the values are within zone boundaries. */ - cc->migrate_pfn = zone->compact_cached_migrate_pfn; + cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync]; cc->free_pfn = zone->compact_cached_free_pfn; if (cc->free_pfn < start_pfn || cc->free_pfn > end_pfn) { cc->free_pfn = end_pfn & ~(pageblock_nr_pages-1); @@ -958,27 +1033,21 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) } if (cc->migrate_pfn < start_pfn || cc->migrate_pfn > end_pfn) { cc->migrate_pfn = start_pfn; - zone->compact_cached_migrate_pfn = cc->migrate_pfn; + zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn; + zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn; } - /* - * Clear pageblock skip if there were failures recently and compaction - * is about to be retried after being deferred. kswapd does not do - * this reset as it'll reset the cached information when going to sleep. - */ - if (compaction_restarting(zone, cc->order) && !current_is_kswapd()) - __reset_isolation_suitable(zone); + trace_mm_compaction_begin(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn); migrate_prep_local(); while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) { - unsigned long nr_migrate, nr_remaining; int err; switch (isolate_migratepages(zone, cc)) { case ISOLATE_ABORT: ret = COMPACT_PARTIAL; - putback_lru_pages(&cc->migratepages); + putback_movable_pages(&cc->migratepages); cc->nr_migratepages = 0; goto out; case ISOLATE_NONE: @@ -987,32 +1056,29 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) ; } - nr_migrate = cc->nr_migratepages; + if (!cc->nr_migratepages) + continue; + err = migrate_pages(&cc->migratepages, compaction_alloc, - (unsigned long)cc, false, - cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC); - update_nr_listpages(cc); - nr_remaining = cc->nr_migratepages; - - count_vm_event(COMPACTBLOCKS); - count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining); - if (nr_remaining) - count_vm_events(COMPACTPAGEFAILED, nr_remaining); - trace_mm_compaction_migratepages(nr_migrate - nr_remaining, - nr_remaining); - - /* Release LRU pages not migrated */ + compaction_free, (unsigned long)cc, cc->mode, + MR_COMPACTION); + + trace_mm_compaction_migratepages(cc->nr_migratepages, err, + &cc->migratepages); + + /* All pages were either migrated or will be released */ + cc->nr_migratepages = 0; if (err) { - putback_lru_pages(&cc->migratepages); - cc->nr_migratepages = 0; - if (err == -ENOMEM) { + putback_movable_pages(&cc->migratepages); + /* + * migrate_pages() may return -ENOMEM when scanners meet + * and we want compact_finished() to detect it + */ + if (err == -ENOMEM && cc->free_pfn > cc->migrate_pfn) { ret = COMPACT_PARTIAL; goto out; } } - - /* Capture a page now if it is a suitable size */ - compact_capture_page(cc); } out: @@ -1020,13 +1086,13 @@ out: cc->nr_freepages -= release_freepages(&cc->freepages); VM_BUG_ON(cc->nr_freepages != 0); + trace_mm_compaction_end(ret); + return ret; } -static unsigned long compact_zone_order(struct zone *zone, - int order, gfp_t gfp_mask, - bool sync, bool *contended, - struct page **page) +static unsigned long compact_zone_order(struct zone *zone, int order, + gfp_t gfp_mask, enum migrate_mode mode, bool *contended) { unsigned long ret; struct compact_control cc = { @@ -1035,8 +1101,7 @@ static unsigned long compact_zone_order(struct zone *zone, .order = order, .migratetype = allocflags_to_migratetype(gfp_mask), .zone = zone, - .sync = sync, - .page = page, + .mode = mode, }; INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); @@ -1058,7 +1123,7 @@ int sysctl_extfrag_threshold = 500; * @order: The order of the current allocation * @gfp_mask: The GFP mask of the current allocation * @nodemask: The allowed nodes to allocate from - * @sync: Whether migration is synchronous or not + * @mode: The migration mode for async, sync light, or sync migration * @contended: Return value that is true if compaction was aborted due to lock contention * @page: Optionally capture a free page of the requested order during compaction * @@ -1066,7 +1131,7 @@ int sysctl_extfrag_threshold = 500; */ unsigned long try_to_compact_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *nodemask, - bool sync, bool *contended, struct page **page) + enum migrate_mode mode, bool *contended) { enum zone_type high_zoneidx = gfp_zone(gfp_mask); int may_enter_fs = gfp_mask & __GFP_FS; @@ -1080,7 +1145,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, if (!order || !may_enter_fs || !may_perform_io) return rc; - count_vm_event(COMPACTSTALL); + count_compact_event(COMPACTSTALL); #ifdef CONFIG_CMA if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) @@ -1091,8 +1156,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, nodemask) { int status; - status = compact_zone_order(zone, order, gfp_mask, sync, - contended, page); + status = compact_zone_order(zone, order, gfp_mask, mode, + contended); rc = max(status, rc); /* If a normal allocation would succeed, stop compacting */ @@ -1106,7 +1171,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, /* Compact all zones within a node */ -static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) +static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) { int zoneid; struct zone *zone; @@ -1127,46 +1192,42 @@ static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) compact_zone(zone, cc); if (cc->order > 0) { - int ok = zone_watermark_ok(zone, cc->order, - low_wmark_pages(zone), 0, 0); - if (ok && cc->order >= zone->compact_order_failed) - zone->compact_order_failed = cc->order + 1; - /* Currently async compaction is never deferred. */ - else if (!ok && cc->sync) - defer_compaction(zone, cc->order); + if (zone_watermark_ok(zone, cc->order, + low_wmark_pages(zone), 0, 0)) + compaction_defer_reset(zone, cc->order, false); } VM_BUG_ON(!list_empty(&cc->freepages)); VM_BUG_ON(!list_empty(&cc->migratepages)); } - - return 0; } -int compact_pgdat(pg_data_t *pgdat, int order) +void compact_pgdat(pg_data_t *pgdat, int order) { struct compact_control cc = { .order = order, - .sync = false, - .page = NULL, + .mode = MIGRATE_ASYNC, }; - return __compact_pgdat(pgdat, &cc); + if (!order) + return; + + __compact_pgdat(pgdat, &cc); } -static int compact_node(int nid) +static void compact_node(int nid) { struct compact_control cc = { .order = -1, - .sync = true, - .page = NULL, + .mode = MIGRATE_SYNC, + .ignore_skip_hint = true, }; - return __compact_pgdat(NODE_DATA(nid), &cc); + __compact_pgdat(NODE_DATA(nid), &cc); } /* Compact all nodes in the system */ -static int compact_nodes(void) +static void compact_nodes(void) { int nid; @@ -1175,8 +1236,6 @@ static int compact_nodes(void) for_each_online_node(nid) compact_node(nid); - - return COMPACT_COMPLETE; } /* The written value is actually unused, all memory is compacted */ @@ -1187,7 +1246,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { if (write) - return compact_nodes(); + compact_nodes(); return 0; } @@ -1201,7 +1260,7 @@ int sysctl_extfrag_handler(struct ctl_table *table, int write, } #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) -ssize_t sysfs_compact_node(struct device *dev, +static ssize_t sysfs_compact_node(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { |