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mm: migration: clean up unmap_and_move() 

unmap_and_move() is one a big messy function.  Clean it up.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Minchan Kim 2011-10-31 17:06:57 -07:00 committed by Linus Torvalds
parent f80c067361
commit 0dabec93de
1 changed files with 40 additions and 35 deletions
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75
mm/migrate.c
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@ -621,38 +621,18 @@ 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.
@ -668,7 +648,7 @@ 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);
}
@ -785,27 +765,52 @@ uncharge:
mem_cgroup_end_migration(mem, page, newpage, rc == 0);
unlock:
unlock_page(page);
out:
return rc;
}
move_newpage:
/*
* 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);
out:
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);
/*
* 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);
dec_zone_page_state(page, NR_ISOLATED_ANON +
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;