From cf5cd5055db22ae301e01294f191bd94b17e7775 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Minchan Kim Date: Mon, 6 Jun 2011 10:10:50 +0900 Subject: [PATCH v3 07/10] migration: clean up unmap_and_move The unmap_and_move is one of big messy functions. This patch try to clean up. It can help readability and make unmap_and_move_ilru simple. unmap_and_move_ilru will be introduced by next patch. Cc: Mel Gorman Cc: Andrea Arcangeli Cc: KAMEZAWA Hiroyuki Cc: Rik van Riel Cc: Johannes Weiner Cc: KOSAKI Motohiro Signed-off-by: Minchan Kim --- mm/migrate.c | 82 +++++++++++++++++++++++++++++++++------------------------ 1 files changed, 47 insertions(+), 35 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 874c081..3aec310 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -645,38 +645,18 @@ static int move_to_new_page(struct page *newpage, struct page *page, return rc; } -/* - * Obtain the lock on page, remove all ptes and migrate the page - * to the newly allocated page in newpage. - */ -static int unmap_and_move(new_page_t get_new_page, unsigned long private, - struct page *page, int force, bool offlining, bool sync) +static int __unmap_and_move(struct page *page, struct page *newpage, + int force, bool offlining, bool sync) { - int rc = 0; - int *result = NULL; - struct page *newpage = get_new_page(page, private, &result); + int rc = -EAGAIN; int remap_swapcache = 1; int charge = 0; struct mem_cgroup *mem; struct anon_vma *anon_vma = NULL; - if (!newpage) - return -ENOMEM; - - if (page_count(page) == 1) { - /* page was freed from under us. So we are done. */ - goto move_newpage; - } - if (unlikely(PageTransHuge(page))) - if (unlikely(split_huge_page(page))) - goto move_newpage; - - /* prepare cgroup just returns 0 or -ENOMEM */ - rc = -EAGAIN; - if (!trylock_page(page)) { if (!force || !sync) - goto move_newpage; + goto out; /* * It's not safe for direct compaction to call lock_page. @@ -692,7 +672,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, * altogether. */ if (current->flags & PF_MEMALLOC) - goto move_newpage; + goto out; lock_page(page); } @@ -813,9 +793,13 @@ uncharge: mem_cgroup_end_migration(mem, page, newpage, rc == 0); unlock: unlock_page(page); +out: + return rc; +} -move_newpage: - if (rc != -EAGAIN) { +static void __put_lru_pages(struct page *page, struct page *newpage) +{ + if (page != NULL) { /* * A page that has been migrated has all references * removed and will be freed. A page that has not been @@ -827,20 +811,48 @@ move_newpage: page_is_file_cache(page)); putback_lru_page(page); } - /* * Move the new page to the LRU. If migration was not successful * then this will free the page. */ putback_lru_page(newpage); +} - if (result) { - if (rc) - *result = rc; - else - *result = page_to_nid(newpage); - } - return rc; +/* + * Obtain the lock on page, remove all ptes and migrate the page + * to the newly allocated page in newpage. + */ +static int unmap_and_move(new_page_t get_new_page, unsigned long private, + struct page *page, int force, bool offlining, bool sync) +{ + int rc = 0; + int *result = NULL; + struct page *newpage = get_new_page(page, private, &result); + + if (!newpage) + return -ENOMEM; + + if (page_count(page) == 1) { + /* page was freed from under us. So we are done. */ + goto out; + } + + if (unlikely(PageTransHuge(page))) + if (unlikely(split_huge_page(page))) + goto out; + + rc = __unmap_and_move(page, newpage, force, offlining, sync); + if (rc == -EAGAIN) + page = NULL; +out: + __put_lru_pages(page, newpage); + if (result) { + if (rc) + *result = rc; + else + *result = page_to_nid(newpage); + } + return rc; } /* -- 1.7.0.4