diff options
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 160 |
1 files changed, 112 insertions, 48 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index edba18aed173..546e571e9d60 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -41,15 +41,17 @@ static inline void count_compact_events(enum vm_event_item item, long delta) static unsigned long release_freepages(struct list_head *freelist) { struct page *page, *next; - unsigned long count = 0; + unsigned long high_pfn = 0; list_for_each_entry_safe(page, next, freelist, lru) { + unsigned long pfn = page_to_pfn(page); list_del(&page->lru); __free_page(page); - count++; + if (pfn > high_pfn) + high_pfn = pfn; } - return count; + return high_pfn; } static void map_pages(struct list_head *list) @@ -195,16 +197,12 @@ static void update_pageblock_skip(struct compact_control *cc, /* 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; } @@ -479,6 +477,16 @@ isolate_freepages_range(struct compact_control *cc, block_end_pfn = min(block_end_pfn, end_pfn); + /* + * pfn could pass the block_end_pfn if isolated freepage + * is more than pageblock order. In this case, we adjust + * scanning range to right one. + */ + if (pfn >= block_end_pfn) { + block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); + block_end_pfn = min(block_end_pfn, end_pfn); + } + if (!pageblock_pfn_to_page(pfn, block_end_pfn, cc->zone)) break; @@ -705,7 +713,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 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++; @@ -784,6 +791,9 @@ isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn, cc->nr_migratepages = 0; break; } + + if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) + break; } acct_isolated(cc->zone, cc); @@ -876,15 +886,6 @@ static void isolate_freepages(struct compact_control *cc) block_start_pfn - pageblock_nr_pages; /* - * 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) - cc->finished_update_free = true; - - /* * isolate_freepages_block() might have aborted due to async * compaction being contended */ @@ -1026,8 +1027,12 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, } acct_isolated(zone, cc); - /* Record where migration scanner will be restarted */ - cc->migrate_pfn = low_pfn; + /* + * Record where migration scanner will be restarted. If we end up in + * the same pageblock as the free scanner, make the scanners fully + * meet so that compact_finished() terminates compaction. + */ + cc->migrate_pfn = (end_pfn <= cc->free_pfn) ? low_pfn : cc->free_pfn; return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE; } @@ -1069,9 +1074,9 @@ static int compact_finished(struct zone *zone, struct compact_control *cc, /* Compaction run is not finished if the watermark is not met */ watermark = low_wmark_pages(zone); - watermark += (1 << cc->order); - if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0)) + if (!zone_watermark_ok(zone, cc->order, watermark, cc->classzone_idx, + cc->alloc_flags)) return COMPACT_CONTINUE; /* Direct compactor: Is a suitable page free? */ @@ -1097,7 +1102,8 @@ static int compact_finished(struct zone *zone, struct compact_control *cc, * COMPACT_PARTIAL - If the allocation would succeed without compaction * COMPACT_CONTINUE - If compaction should run now */ -unsigned long compaction_suitable(struct zone *zone, int order) +unsigned long compaction_suitable(struct zone *zone, int order, + int alloc_flags, int classzone_idx) { int fragindex; unsigned long watermark; @@ -1109,21 +1115,30 @@ unsigned long compaction_suitable(struct zone *zone, int order) if (order == -1) return COMPACT_CONTINUE; + watermark = low_wmark_pages(zone); + /* + * If watermarks for high-order allocation are already met, there + * should be no need for compaction at all. + */ + if (zone_watermark_ok(zone, order, watermark, classzone_idx, + alloc_flags)) + return COMPACT_PARTIAL; + /* * Watermarks for order-0 must be met for compaction. Note the 2UL. * This is because during migration, copies of pages need to be * allocated and for a short time, the footprint is higher */ - watermark = low_wmark_pages(zone) + (2UL << order); - if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) + watermark += (2UL << order); + if (!zone_watermark_ok(zone, 0, watermark, classzone_idx, alloc_flags)) return COMPACT_SKIPPED; /* * fragmentation index determines if allocation failures are due to * low memory or external fragmentation * - * index of -1000 implies allocations might succeed depending on - * watermarks + * index of -1000 would imply allocations might succeed depending on + * watermarks, but we already failed the high-order watermark check * index towards 0 implies failure is due to lack of memory * index towards 1000 implies failure is due to fragmentation * @@ -1133,10 +1148,6 @@ unsigned long compaction_suitable(struct zone *zone, int order) if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold) return COMPACT_SKIPPED; - if (fragindex == -1000 && zone_watermark_ok(zone, order, watermark, - 0, 0)) - return COMPACT_PARTIAL; - return COMPACT_CONTINUE; } @@ -1147,8 +1158,10 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) unsigned long end_pfn = zone_end_pfn(zone); const int migratetype = gfpflags_to_migratetype(cc->gfp_mask); const bool sync = cc->mode != MIGRATE_ASYNC; + unsigned long last_migrated_pfn = 0; - ret = compaction_suitable(zone, cc->order); + ret = compaction_suitable(zone, cc->order, cc->alloc_flags, + cc->classzone_idx); switch (ret) { case COMPACT_PARTIAL: case COMPACT_SKIPPED: @@ -1191,6 +1204,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) while ((ret = compact_finished(zone, cc, migratetype)) == COMPACT_CONTINUE) { int err; + unsigned long isolate_start_pfn = cc->migrate_pfn; switch (isolate_migratepages(zone, cc)) { case ISOLATE_ABORT: @@ -1199,7 +1213,12 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) cc->nr_migratepages = 0; goto out; case ISOLATE_NONE: - continue; + /* + * We haven't isolated and migrated anything, but + * there might still be unflushed migrations from + * previous cc->order aligned block. + */ + goto check_drain; case ISOLATE_SUCCESS: ; } @@ -1224,12 +1243,61 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) goto out; } } + + /* + * Record where we could have freed pages by migration and not + * yet flushed them to buddy allocator. We use the pfn that + * isolate_migratepages() started from in this loop iteration + * - this is the lowest page that could have been isolated and + * then freed by migration. + */ + if (!last_migrated_pfn) + last_migrated_pfn = isolate_start_pfn; + +check_drain: + /* + * Has the migration scanner moved away from the previous + * cc->order aligned block where we migrated from? If yes, + * flush the pages that were freed, so that they can merge and + * compact_finished() can detect immediately if allocation + * would succeed. + */ + if (cc->order > 0 && last_migrated_pfn) { + int cpu; + unsigned long current_block_start = + cc->migrate_pfn & ~((1UL << cc->order) - 1); + + if (last_migrated_pfn < current_block_start) { + cpu = get_cpu(); + lru_add_drain_cpu(cpu); + drain_local_pages(zone); + put_cpu(); + /* No more flushing until we migrate again */ + last_migrated_pfn = 0; + } + } + } out: - /* Release free pages and check accounting */ - cc->nr_freepages -= release_freepages(&cc->freepages); - VM_BUG_ON(cc->nr_freepages != 0); + /* + * Release free pages and update where the free scanner should restart, + * so we don't leave any returned pages behind in the next attempt. + */ + if (cc->nr_freepages > 0) { + unsigned long free_pfn = release_freepages(&cc->freepages); + + cc->nr_freepages = 0; + VM_BUG_ON(free_pfn == 0); + /* The cached pfn is always the first in a pageblock */ + free_pfn &= ~(pageblock_nr_pages-1); + /* + * Only go back, not forward. The cached pfn might have been + * already reset to zone end in compact_finished() + */ + if (free_pfn > zone->compact_cached_free_pfn) + zone->compact_cached_free_pfn = free_pfn; + } trace_mm_compaction_end(ret); @@ -1237,7 +1305,8 @@ out: } static unsigned long compact_zone_order(struct zone *zone, int order, - gfp_t gfp_mask, enum migrate_mode mode, int *contended) + gfp_t gfp_mask, enum migrate_mode mode, int *contended, + int alloc_flags, int classzone_idx) { unsigned long ret; struct compact_control cc = { @@ -1247,6 +1316,8 @@ static unsigned long compact_zone_order(struct zone *zone, int order, .gfp_mask = gfp_mask, .zone = zone, .mode = mode, + .alloc_flags = alloc_flags, + .classzone_idx = classzone_idx, }; INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); @@ -1271,14 +1342,13 @@ int sysctl_extfrag_threshold = 500; * @mode: The migration mode for async, sync light, or sync migration * @contended: Return value that determines if compaction was aborted due to * need_resched() or lock contention - * @candidate_zone: Return the zone where we think allocation should succeed * * This is the main entry point for direct page compaction. */ unsigned long try_to_compact_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *nodemask, enum migrate_mode mode, int *contended, - struct zone **candidate_zone) + int alloc_flags, int classzone_idx) { enum zone_type high_zoneidx = gfp_zone(gfp_mask); int may_enter_fs = gfp_mask & __GFP_FS; @@ -1286,7 +1356,6 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, struct zoneref *z; struct zone *zone; int rc = COMPACT_DEFERRED; - int alloc_flags = 0; int all_zones_contended = COMPACT_CONTENDED_LOCK; /* init for &= op */ *contended = COMPACT_CONTENDED_NONE; @@ -1295,10 +1364,6 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, if (!order || !may_enter_fs || !may_perform_io) return COMPACT_SKIPPED; -#ifdef CONFIG_CMA - if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) - alloc_flags |= ALLOC_CMA; -#endif /* Compact each zone in the list */ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, nodemask) { @@ -1309,7 +1374,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, continue; status = compact_zone_order(zone, order, gfp_mask, mode, - &zone_contended); + &zone_contended, alloc_flags, classzone_idx); rc = max(status, rc); /* * It takes at least one zone that wasn't lock contended @@ -1318,9 +1383,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, all_zones_contended &= zone_contended; /* If a normal allocation would succeed, stop compacting */ - if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, - alloc_flags)) { - *candidate_zone = zone; + if (zone_watermark_ok(zone, order, low_wmark_pages(zone), + classzone_idx, alloc_flags)) { /* * We think the allocation will succeed in this zone, * but it is not certain, hence the false. The caller @@ -1342,7 +1406,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, goto break_loop; } - if (mode != MIGRATE_ASYNC) { + if (mode != MIGRATE_ASYNC && status == COMPACT_COMPLETE) { /* * We think that allocation won't succeed in this zone * so we defer compaction there. If it ends up |