diff options
author | Christoph Lameter <clameter@sgi.com> | 2006-06-23 13:03:53 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 18:42:53 +0400 |
commit | 95a402c3847cc16f4ba03013cd01404fa0f14c2e (patch) | |
tree | 0fd9b3379f70cc99b2325bccaa150089abf6c8b3 /mm/migrate.c | |
parent | aaa994b300a172afafab47938804836b923e5ef7 (diff) | |
download | linux-95a402c3847cc16f4ba03013cd01404fa0f14c2e.tar.xz |
[PATCH] page migration: use allocator function for migrate_pages()
Instead of passing a list of new pages, pass a function to allocate a new
page. This allows the correct placement of MPOL_INTERLEAVE pages during page
migration. It also further simplifies the callers of migrate pages.
migrate_pages() becomes similar to migrate_pages_to() so drop
migrate_pages_to(). The batching of new page allocations becomes unnecessary.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/migrate.c')
-rw-r--r-- | mm/migrate.c | 115 |
1 files changed, 32 insertions, 83 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index d3a1810a4c9f..251a8d158257 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -28,9 +28,6 @@ #include "internal.h" -/* The maximum number of pages to take off the LRU for migration */ -#define MIGRATE_CHUNK_SIZE 256 - #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru)) /* @@ -587,18 +584,23 @@ static int move_to_new_page(struct page *newpage, struct page *page) * Obtain the lock on page, remove all ptes and migrate the page * to the newly allocated page in newpage. */ -static int unmap_and_move(struct page *newpage, struct page *page, int force) +static int unmap_and_move(new_page_t get_new_page, unsigned long private, + struct page *page, int force) { int rc = 0; + struct page *newpage = get_new_page(page, private); + + if (!newpage) + return -ENOMEM; if (page_count(page) == 1) /* page was freed from under us. So we are done. */ - goto ret; + goto move_newpage; rc = -EAGAIN; if (TestSetPageLocked(page)) { if (!force) - goto ret; + goto move_newpage; lock_page(page); } @@ -622,7 +624,7 @@ static int unmap_and_move(struct page *newpage, struct page *page, int force) remove_migration_ptes(page, page); unlock: unlock_page(page); -ret: + if (rc != -EAGAIN) { /* * A page that has been migrated has all references @@ -632,29 +634,33 @@ ret: */ list_del(&page->lru); move_to_lru(page); - - list_del(&newpage->lru); - move_to_lru(newpage); } + +move_newpage: + /* + * Move the new page to the LRU. If migration was not successful + * then this will free the page. + */ + move_to_lru(newpage); return rc; } /* * migrate_pages * - * Two lists are passed to this function. The first list - * contains the pages isolated from the LRU to be migrated. - * The second list contains new pages that the isolated pages - * can be moved to. + * The function takes one list of pages to migrate and a function + * that determines from the page to be migrated and the private data + * the target of the move and allocates the page. * * The function returns after 10 attempts or if no pages * are movable anymore because to has become empty * or no retryable pages exist anymore. All pages will be * retruned to the LRU or freed. * - * Return: Number of pages not migrated. + * Return: Number of pages not migrated or error code. */ -int migrate_pages(struct list_head *from, struct list_head *to) +int migrate_pages(struct list_head *from, + new_page_t get_new_page, unsigned long private) { int retry = 1; int nr_failed = 0; @@ -671,15 +677,14 @@ int migrate_pages(struct list_head *from, struct list_head *to) retry = 0; list_for_each_entry_safe(page, page2, from, lru) { - - if (list_empty(to)) - break; - cond_resched(); - rc = unmap_and_move(lru_to_page(to), page, pass > 2); + rc = unmap_and_move(get_new_page, private, + page, pass > 2); switch(rc) { + case -ENOMEM: + goto out; case -EAGAIN: retry++; break; @@ -692,72 +697,16 @@ int migrate_pages(struct list_head *from, struct list_head *to) } } } - + rc = 0; +out: if (!swapwrite) current->flags &= ~PF_SWAPWRITE; putback_lru_pages(from); - return nr_failed + retry; -} -/* - * Migrate the list 'pagelist' of pages to a certain destination. - * - * Specify destination with either non-NULL vma or dest_node >= 0 - * Return the number of pages not migrated or error code - */ -int migrate_pages_to(struct list_head *pagelist, - struct vm_area_struct *vma, int dest) -{ - LIST_HEAD(newlist); - int err = 0; - unsigned long offset = 0; - int nr_pages; - int nr_failed = 0; - struct page *page; - struct list_head *p; - -redo: - nr_pages = 0; - list_for_each(p, pagelist) { - if (vma) { - /* - * The address passed to alloc_page_vma is used to - * generate the proper interleave behavior. We fake - * the address here by an increasing offset in order - * to get the proper distribution of pages. - * - * No decision has been made as to which page - * a certain old page is moved to so we cannot - * specify the correct address. - */ - page = alloc_page_vma(GFP_HIGHUSER, vma, - offset + vma->vm_start); - offset += PAGE_SIZE; - } - else - page = alloc_pages_node(dest, GFP_HIGHUSER, 0); - - if (!page) { - err = -ENOMEM; - goto out; - } - list_add_tail(&page->lru, &newlist); - nr_pages++; - if (nr_pages > MIGRATE_CHUNK_SIZE) - break; - } - err = migrate_pages(pagelist, &newlist); - - if (err >= 0) { - nr_failed += err; - if (list_empty(&newlist) && !list_empty(pagelist)) - goto redo; - } -out: + if (rc) + return rc; - /* Calculate number of leftover pages */ - list_for_each(p, pagelist) - nr_failed++; - return nr_failed; + return nr_failed + retry; } + |