From aaa994b300a172afafab47938804836b923e5ef7 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 23 Jun 2006 02:03:52 -0700 Subject: [PATCH] page migration: handle freeing of pages in migrate_pages() Do not leave pages on the lists passed to migrate_pages(). Seems that we will not need any postprocessing of pages. This will simplify the handling of pages by the callers of migrate_pages(). Signed-off-by: Christoph Lameter Cc: Hugh Dickins Cc: Jes Sorensen Cc: KAMEZAWA Hiroyuki Cc: Lee Schermerhorn Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/migrate.c | 48 +++++++++++++++++++++++------------------------- 1 file changed, 23 insertions(+), 25 deletions(-) (limited to 'mm/migrate.c') diff --git a/mm/migrate.c b/mm/migrate.c index 09038163bfe..d3a1810a4c9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -624,6 +624,15 @@ unlock: unlock_page(page); ret: if (rc != -EAGAIN) { + /* + * A page that has been migrated has all references + * removed and will be freed. A page that has not been + * migrated will have kepts its references and be + * restored. + */ + list_del(&page->lru); + move_to_lru(page); + list_del(&newpage->lru); move_to_lru(newpage); } @@ -640,12 +649,12 @@ ret: * * The function returns after 10 attempts or if no pages * are movable anymore because to has become empty - * or no retryable pages exist anymore. + * or no retryable pages exist anymore. All pages will be + * retruned to the LRU or freed. * - * Return: Number of pages not migrated when "to" ran empty. + * Return: Number of pages not migrated. */ -int migrate_pages(struct list_head *from, struct list_head *to, - struct list_head *moved, struct list_head *failed) +int migrate_pages(struct list_head *from, struct list_head *to) { int retry = 1; int nr_failed = 0; @@ -675,11 +684,9 @@ int migrate_pages(struct list_head *from, struct list_head *to, retry++; break; case 0: - list_move(&page->lru, moved); break; default: /* Permanent failure */ - list_move(&page->lru, failed); nr_failed++; break; } @@ -689,6 +696,7 @@ int migrate_pages(struct list_head *from, struct list_head *to, if (!swapwrite) current->flags &= ~PF_SWAPWRITE; + putback_lru_pages(from); return nr_failed + retry; } @@ -702,11 +710,10 @@ int migrate_pages_to(struct list_head *pagelist, struct vm_area_struct *vma, int dest) { LIST_HEAD(newlist); - LIST_HEAD(moved); - LIST_HEAD(failed); int err = 0; unsigned long offset = 0; int nr_pages; + int nr_failed = 0; struct page *page; struct list_head *p; @@ -740,26 +747,17 @@ redo: if (nr_pages > MIGRATE_CHUNK_SIZE) break; } - err = migrate_pages(pagelist, &newlist, &moved, &failed); + err = migrate_pages(pagelist, &newlist); - putback_lru_pages(&moved); /* Call release pages instead ?? */ - - if (err >= 0 && list_empty(&newlist) && !list_empty(pagelist)) - goto redo; -out: - /* Return leftover allocated pages */ - while (!list_empty(&newlist)) { - page = list_entry(newlist.next, struct page, lru); - list_del(&page->lru); - __free_page(page); + if (err >= 0) { + nr_failed += err; + if (list_empty(&newlist) && !list_empty(pagelist)) + goto redo; } - list_splice(&failed, pagelist); - if (err < 0) - return err; +out: /* Calculate number of leftover pages */ - nr_pages = 0; list_for_each(p, pagelist) - nr_pages++; - return nr_pages; + nr_failed++; + return nr_failed; } -- cgit v1.2.3