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[PATCH] page migration: handle freeing of pages in migrate_pages()

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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 <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>
This commit is contained in:
Christoph Lameter 2006-06-23 02:03:52 -07:00 committed by Linus Torvalds
parent e24f0b8f76
commit aaa994b300
3 changed files with 27 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/migrate.h
View File

@ -8,8 +8,7 @@ extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
extern int putback_lru_pages(struct list_head *l);
extern int migrate_page(struct address_space *,
struct page *, struct page *);
extern int migrate_pages(struct list_head *l, struct list_head *t,
struct list_head *moved, struct list_head *failed);
extern int migrate_pages(struct list_head *l, struct list_head *t);
extern int migrate_pages_to(struct list_head *pagelist,
struct vm_area_struct *vma, int dest);
extern int fail_migrate_page(struct address_space *,
@ -22,8 +21,8 @@ extern int migrate_prep(void);
static inline int isolate_lru_page(struct page *p, struct list_head *list)
{ return -ENOSYS; }
static inline int putback_lru_pages(struct list_head *l) { return 0; }
static inline int migrate_pages(struct list_head *l, struct list_head *t,
struct list_head *moved, struct list_head *failed) { return -ENOSYS; }
static inline int migrate_pages(struct list_head *l, struct list_head *t)
{ return -ENOSYS; }
static inline int migrate_pages_to(struct list_head *pagelist,
struct vm_area_struct *vma, int dest) { return 0; }

8
mm/mempolicy.c
View File

@ -603,11 +603,8 @@ int migrate_to_node(struct mm_struct *mm, int source, int dest, int flags)
check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
if (!list_empty(&pagelist)) {
err = migrate_pages_to(&pagelist, NULL, dest);
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);
}
err = migrate_pages_to(&pagelist, NULL, dest);
return err;
}
@ -773,9 +770,6 @@ long do_mbind(unsigned long start, unsigned long len,
err = -EIO;
}
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);
up_write(&mm->mmap_sem);
mpol_free(new);
return err;

46
mm/migrate.c
View File

@ -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))
if (err >= 0) {
nr_failed += err;
if (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);
}
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;
}