From b1123ea6d3b3da25af5c8a9d843bd07ab63213f4 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 26 Jul 2016 15:23:09 -0700 Subject: mm: balloon: use general non-lru movable page feature Now, VM has a feature to migrate non-lru movable pages so balloon doesn't need custom migration hooks in migrate.c and compaction.c. Instead, this patch implements the page->mapping->a_ops-> {isolate|migrate|putback} functions. With that, we could remove hooks for ballooning in general migration functions and make balloon compaction simple. [akpm@linux-foundation.org: compaction.h requires that the includer first include node.h] Link: http://lkml.kernel.org/r/1464736881-24886-4-git-send-email-minchan@kernel.org Signed-off-by: Gioh Kim Signed-off-by: Minchan Kim Acked-by: Vlastimil Babka Cc: Rafael Aquini Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/balloon_compaction.c | 94 +++++++++---------------------------------------- mm/compaction.c | 7 ---- mm/migrate.c | 19 ++-------- mm/vmscan.c | 2 +- 4 files changed, 20 insertions(+), 102 deletions(-) (limited to 'mm') diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 57b3e9bd6bc5..da91df50ba31 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -70,7 +70,7 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) */ if (trylock_page(page)) { #ifdef CONFIG_BALLOON_COMPACTION - if (!PagePrivate(page)) { + if (PageIsolated(page)) { /* raced with isolation */ unlock_page(page); continue; @@ -106,110 +106,50 @@ EXPORT_SYMBOL_GPL(balloon_page_dequeue); #ifdef CONFIG_BALLOON_COMPACTION -static inline void __isolate_balloon_page(struct page *page) +bool balloon_page_isolate(struct page *page, isolate_mode_t mode) + { struct balloon_dev_info *b_dev_info = balloon_page_device(page); 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); + + return true; } -static inline void __putback_balloon_page(struct page *page) +void balloon_page_putback(struct page *page) { struct balloon_dev_info *b_dev_info = balloon_page_device(page); 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); } -/* __isolate_lru_page() counterpart for a ballooned page */ -bool balloon_page_isolate(struct page *page) -{ - /* - * Avoid burning cycles with pages that are yet under __free_pages(), - * or just got freed under us. - * - * In case we 'win' a race for a balloon page being freed under us and - * raise its refcount preventing __free_pages() from doing its job - * the put_page() at the end of this block will take care of - * release this page, thus avoiding a nasty leakage. - */ - if (likely(get_page_unless_zero(page))) { - /* - * As balloon pages are not isolated from LRU lists, concurrent - * compaction threads can race against page migration functions - * as well as race against the balloon driver releasing a page. - * - * In order to avoid having an already isolated balloon page - * being (wrongly) re-isolated while it is under migration, - * or to avoid attempting to isolate pages being released by - * the balloon driver, lets be sure we have the page lock - * before proceeding with the balloon page isolation steps. - */ - if (likely(trylock_page(page))) { - /* - * A ballooned page, by default, has PagePrivate set. - * Prevent concurrent compaction threads from isolating - * an already isolated balloon page by clearing it. - */ - if (balloon_page_movable(page)) { - __isolate_balloon_page(page); - unlock_page(page); - return true; - } - unlock_page(page); - } - put_page(page); - } - return false; -} - -/* putback_lru_page() counterpart for a ballooned page */ -void balloon_page_putback(struct page *page) -{ - /* - * 'lock_page()' stabilizes the page and prevents races against - * concurrent isolation threads attempting to re-isolate it. - */ - lock_page(page); - - if (__is_movable_balloon_page(page)) { - __putback_balloon_page(page); - /* drop the extra ref count taken for page isolation */ - put_page(page); - } else { - WARN_ON(1); - dump_page(page, "not movable balloon page"); - } - unlock_page(page); -} /* move_to_new_page() counterpart for a ballooned page */ -int balloon_page_migrate(struct page *newpage, - struct page *page, enum migrate_mode mode) +int balloon_page_migrate(struct address_space *mapping, + struct page *newpage, struct page *page, + enum migrate_mode mode) { struct balloon_dev_info *balloon = balloon_page_device(page); - int rc = -EAGAIN; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); - if (WARN_ON(!__is_movable_balloon_page(page))) { - dump_page(page, "not movable balloon page"); - return rc; - } + return balloon->migratepage(balloon, newpage, page, mode); +} - if (balloon && balloon->migratepage) - rc = balloon->migratepage(balloon, newpage, page, mode); +const struct address_space_operations balloon_aops = { + .migratepage = balloon_page_migrate, + .isolate_page = balloon_page_isolate, + .putback_page = balloon_page_putback, +}; +EXPORT_SYMBOL_GPL(balloon_aops); - return rc; -} #endif /* CONFIG_BALLOON_COMPACTION */ diff --git a/mm/compaction.c b/mm/compaction.c index fe95d8d021c3..d85520647d1d 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -791,13 +791,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, * Skip any other type of page */ if (!PageLRU(page)) { - if (unlikely(balloon_page_movable(page))) { - if (balloon_page_isolate(page)) { - /* Successfully isolated */ - goto isolate_success; - } - } - /* * __PageMovable can return false positive so we need * to verify it under page_lock. diff --git a/mm/migrate.c b/mm/migrate.c index 8119fdc563f8..f278005f609c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -170,14 +170,12 @@ void putback_movable_pages(struct list_head *l) list_del(&page->lru); dec_zone_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); - if (unlikely(isolated_balloon_page(page))) { - balloon_page_putback(page); /* * We isolated non-lru movable page so here we can use * __PageMovable because LRU page's mapping cannot have * PAGE_MAPPING_MOVABLE. */ - } else if (unlikely(__PageMovable(page))) { + if (unlikely(__PageMovable(page))) { VM_BUG_ON_PAGE(!PageIsolated(page), page); lock_page(page); if (PageMovable(page)) @@ -992,18 +990,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage, if (unlikely(!trylock_page(newpage))) goto out_unlock; - if (unlikely(isolated_balloon_page(page))) { - /* - * A ballooned page does not need any special attention from - * physical to virtual reverse mapping procedures. - * Skip any attempt to unmap PTEs or to remap swap cache, - * in order to avoid burning cycles at rmap level, and perform - * the page migration right away (proteced by page lock). - */ - rc = balloon_page_migrate(newpage, page, mode); - goto out_unlock_both; - } - if (unlikely(!is_lru)) { rc = move_to_new_page(newpage, page, mode); goto out_unlock_both; @@ -1058,8 +1044,7 @@ out: * list in here. */ if (rc == MIGRATEPAGE_SUCCESS) { - if (unlikely(__is_movable_balloon_page(newpage) || - __PageMovable(newpage))) + if (unlikely(__PageMovable(newpage))) put_page(newpage); else putback_lru_page(newpage); diff --git a/mm/vmscan.c b/mm/vmscan.c index c4a2f4512fca..93ba33789ac6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1254,7 +1254,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, list_for_each_entry_safe(page, next, page_list, lru) { if (page_is_file_cache(page) && !PageDirty(page) && - !isolated_balloon_page(page)) { + !__PageMovable(page)) { ClearPageActive(page); list_move(&page->lru, &clean_pages); } -- cgit v1.2.3