If we found lazyfree page is dirty, ttuo can just SetPageSwapBakced in there like PG_mlocked page and just return with SWAP_FAIL which is very natural because the page is not swappable right now so that vmscan can activate it. There is no point to introduce new return value SWAP_DIRTY in ttu at the moment.
Cc: Shaohua Li <[email protected]> Signed-off-by: Minchan Kim <[email protected]> --- include/linux/rmap.h | 1 - mm/rmap.c | 4 ++-- mm/vmscan.c | 3 --- 3 files changed, 2 insertions(+), 6 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index fee10d7..b556eef 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -298,6 +298,5 @@ static inline int page_mkclean(struct page *page) #define SWAP_AGAIN 1 #define SWAP_FAIL 2 #define SWAP_MLOCK 3 -#define SWAP_DIRTY 4 #endif /* _LINUX_RMAP_H */ diff --git a/mm/rmap.c b/mm/rmap.c index 8076347..3a14013 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1424,7 +1424,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, } else if (!PageSwapBacked(page)) { /* dirty MADV_FREE page */ set_pte_at(mm, address, pvmw.pte, pteval); - ret = SWAP_DIRTY; + SetPageSwapBacked(page); + ret = SWAP_FAIL; page_vma_mapped_walk_done(&pvmw); break; } @@ -1494,7 +1495,6 @@ static int page_mapcount_is_zero(struct page *page) * SWAP_AGAIN - we missed a mapping, try again later * SWAP_FAIL - the page is unswappable * SWAP_MLOCK - page is mlocked. - * SWAP_DIRTY - page is dirty MADV_FREE page */ int try_to_unmap(struct page *page, enum ttu_flags flags) { diff --git a/mm/vmscan.c b/mm/vmscan.c index 7aa89e3..91cef05 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1141,9 +1141,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (page_mapped(page)) { switch (ret = try_to_unmap(page, ttu_flags | TTU_BATCH_FLUSH)) { - case SWAP_DIRTY: - SetPageSwapBacked(page); - /* fall through */ case SWAP_FAIL: nr_unmap_fail++; goto activate_locked; -- 2.7.4
