Commit ad6b6704 authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds
Browse files

mm: remove SWAP_MLOCK in ttu 

ttu doesn't need to return SWAP_MLOCK.  Instead, just return SWAP_FAIL
because it means the page is not-swappable so it should move to another
LRU list(active or unevictable).  putback friends will move it to right
list depending on the page's LRU flag.

Link: http://lkml.kernel.org/r/1489555493-14659-6-git-send-email-minchan@kernel.org


Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 192d7232

include/linux/rmap.h

+0 −1
Original line number Diff line number Diff line
@@ -297,6 +297,5 @@ static inline int page_mkclean(struct page *page) 
#define SWAP_SUCCESS	0

#define SWAP_AGAIN	1

#define SWAP_FAIL	2

#define SWAP_MLOCK	3



#endif	/* _LINUX_RMAP_H */

mm/rmap.c

+1 −2
Original line number Diff line number Diff line
@@ -1329,7 +1329,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, 
					 */

					mlock_vma_page(page);

				}

				ret = SWAP_MLOCK;

				ret = SWAP_FAIL;

				page_vma_mapped_walk_done(&pvmw);

				break;

			}
@@ -1506,7 +1506,6 @@ static int page_mapcount_is_zero(struct page *page) 
 * SWAP_SUCCESS	- we succeeded in removing all mappings

 * SWAP_AGAIN	- we missed a mapping, try again later

 * SWAP_FAIL	- the page is unswappable

 * SWAP_MLOCK	- page is mlocked.

 */

int try_to_unmap(struct page *page, enum ttu_flags flags)

{

mm/vmscan.c

+7 −13
Original line number Diff line number Diff line
@@ -987,7 +987,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, 
		sc->nr_scanned++;



		if (unlikely(!page_evictable(page)))

			goto cull_mlocked;

			goto activate_locked;



		if (!sc->may_unmap && page_mapped(page))

			goto keep_locked;
@@ -1152,8 +1152,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, 
				goto activate_locked;

			case SWAP_AGAIN:

				goto keep_locked;

			case SWAP_MLOCK:

				goto cull_mlocked;

			case SWAP_SUCCESS:

				; /* try to free the page below */

			}
@@ -1295,20 +1293,16 @@ free_it: 
		list_add(&page->lru, &free_pages);

		continue;



cull_mlocked:

		if (PageSwapCache(page))

			try_to_free_swap(page);

		unlock_page(page);

		list_add(&page->lru, &ret_pages);

		continue;



activate_locked:

		/* Not a candidate for swapping, so reclaim swap space. */

		if (PageSwapCache(page) && mem_cgroup_swap_full(page))

		if (PageSwapCache(page) && (mem_cgroup_swap_full(page) ||

						PageMlocked(page)))

			try_to_free_swap(page);

		VM_BUG_ON_PAGE(PageActive(page), page);

		if (!PageMlocked(page)) {

			SetPageActive(page);

			pgactivate++;

		}

keep_locked:

		unlock_page(page);

keep:

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