diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/balloon_compaction.c | 26 | ||||
| -rw-r--r-- | mm/compaction.c | 2 | ||||
| -rw-r--r-- | mm/migrate.c | 16 |
3 files changed, 17 insertions, 27 deletions
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 6e45a5074bf0..52abeeb3cb9d 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -93,17 +93,12 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) * to be released by the balloon driver. */ if (trylock_page(page)) { + if (!PagePrivate(page)) { + /* raced with isolation */ + unlock_page(page); + continue; + } spin_lock_irqsave(&b_dev_info->pages_lock, flags); - /* - * Raise the page refcount here to prevent any wrong - * attempt to isolate this page, in case of coliding - * with balloon_page_isolate() just after we release - * the page lock. - * - * balloon_page_free() will take care of dropping - * this extra refcount later. - */ - get_page(page); balloon_page_delete(page); spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); unlock_page(page); @@ -187,7 +182,9 @@ static inline void __isolate_balloon_page(struct page *page) { struct balloon_dev_info *b_dev_info = page->mapping->private_data; unsigned long flags; + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + ClearPagePrivate(page); list_del(&page->lru); b_dev_info->isolated_pages++; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); @@ -197,7 +194,9 @@ static inline void __putback_balloon_page(struct page *page) { struct balloon_dev_info *b_dev_info = page->mapping->private_data; unsigned long flags; + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + SetPagePrivate(page); list_add(&page->lru, &b_dev_info->pages); b_dev_info->isolated_pages--; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); @@ -235,12 +234,11 @@ bool balloon_page_isolate(struct page *page) */ if (likely(trylock_page(page))) { /* - * A ballooned page, by default, has just one refcount. + * A ballooned page, by default, has PagePrivate set. * Prevent concurrent compaction threads from isolating - * an already isolated balloon page by refcount check. + * an already isolated balloon page by clearing it. */ - if (__is_movable_balloon_page(page) && - page_count(page) == 2) { + if (balloon_page_movable(page)) { __isolate_balloon_page(page); unlock_page(page); return true; diff --git a/mm/compaction.c b/mm/compaction.c index b9972c0fd917..edba18aed173 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -640,7 +640,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, */ if (!PageLRU(page)) { if (unlikely(balloon_page_movable(page))) { - if (locked && balloon_page_isolate(page)) { + if (balloon_page_isolate(page)) { /* Successfully isolated */ goto isolate_success; } diff --git a/mm/migrate.c b/mm/migrate.c index 2740360cd216..01439953abf5 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -876,7 +876,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage, } } - if (unlikely(balloon_page_movable(page))) { + if (unlikely(isolated_balloon_page(page))) { /* * A ballooned page does not need any special attention from * physical to virtual reverse mapping procedures. @@ -955,17 +955,6 @@ static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page, rc = __unmap_and_move(page, newpage, force, mode); - if (unlikely(rc == MIGRATEPAGE_BALLOON_SUCCESS)) { - /* - * A ballooned page has been migrated already. - * Now, it's the time to wrap-up counters, - * handle the page back to Buddy and return. - */ - dec_zone_page_state(page, NR_ISOLATED_ANON + - page_is_file_cache(page)); - balloon_page_free(page); - return MIGRATEPAGE_SUCCESS; - } out: if (rc != -EAGAIN) { /* @@ -988,6 +977,9 @@ out: if (rc != MIGRATEPAGE_SUCCESS && put_new_page) { ClearPageSwapBacked(newpage); put_new_page(newpage, private); + } else if (unlikely(__is_movable_balloon_page(newpage))) { + /* drop our reference, page already in the balloon */ + put_page(newpage); } else putback_lru_page(newpage); |