Commit 0f074658 authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds

mm, THP, swap: move anonymous THP split logic to vmscan

The add_to_swap aims to allocate swap_space(ie, swap slot and swapcache)
so if it fails due to lack of space in case of THP or something(hdd swap
but tries THP swapout) *caller* rather than add_to_swap itself should
split the THP page and retry it with base page which is more natural.

Link: http://lkml.kernel.org/r/20170515112522.32457-4-ying.huang@intel.comSigned-off-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 75f6d6d2
...@@ -353,7 +353,7 @@ extern struct address_space *swapper_spaces[]; ...@@ -353,7 +353,7 @@ extern struct address_space *swapper_spaces[];
>> SWAP_ADDRESS_SPACE_SHIFT]) >> SWAP_ADDRESS_SPACE_SHIFT])
extern unsigned long total_swapcache_pages(void); extern unsigned long total_swapcache_pages(void);
extern void show_swap_cache_info(void); extern void show_swap_cache_info(void);
extern int add_to_swap(struct page *, struct list_head *list); extern int add_to_swap(struct page *page);
extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); extern int __add_to_swap_cache(struct page *page, swp_entry_t entry);
extern void __delete_from_swap_cache(struct page *); extern void __delete_from_swap_cache(struct page *);
...@@ -473,7 +473,7 @@ static inline struct page *lookup_swap_cache(swp_entry_t swp) ...@@ -473,7 +473,7 @@ static inline struct page *lookup_swap_cache(swp_entry_t swp)
return NULL; return NULL;
} }
static inline int add_to_swap(struct page *page, struct list_head *list) static inline int add_to_swap(struct page *page)
{ {
return 0; return 0;
} }
......
...@@ -184,7 +184,7 @@ void __delete_from_swap_cache(struct page *page) ...@@ -184,7 +184,7 @@ void __delete_from_swap_cache(struct page *page)
* Allocate swap space for the page and add the page to the * Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock. * swap cache. Caller needs to hold the page lock.
*/ */
int add_to_swap(struct page *page, struct list_head *list) int add_to_swap(struct page *page)
{ {
swp_entry_t entry; swp_entry_t entry;
int err; int err;
...@@ -192,12 +192,12 @@ int add_to_swap(struct page *page, struct list_head *list) ...@@ -192,12 +192,12 @@ int add_to_swap(struct page *page, struct list_head *list)
VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageUptodate(page), page); VM_BUG_ON_PAGE(!PageUptodate(page), page);
retry:
entry = get_swap_page(page); entry = get_swap_page(page);
if (!entry.val) if (!entry.val)
goto fail; return 0;
if (mem_cgroup_try_charge_swap(page, entry)) if (mem_cgroup_try_charge_swap(page, entry))
goto fail_free; goto fail;
/* /*
* Radix-tree node allocations from PF_MEMALLOC contexts could * Radix-tree node allocations from PF_MEMALLOC contexts could
...@@ -218,23 +218,12 @@ int add_to_swap(struct page *page, struct list_head *list) ...@@ -218,23 +218,12 @@ int add_to_swap(struct page *page, struct list_head *list)
* add_to_swap_cache() doesn't return -EEXIST, so we can safely * add_to_swap_cache() doesn't return -EEXIST, so we can safely
* clear SWAP_HAS_CACHE flag. * clear SWAP_HAS_CACHE flag.
*/ */
goto fail_free; goto fail;
if (PageTransHuge(page)) {
err = split_huge_page_to_list(page, list);
if (err) {
delete_from_swap_cache(page);
return 0;
}
}
return 1; return 1;
fail_free:
put_swap_page(page, entry);
fail: fail:
if (PageTransHuge(page) && !split_huge_page_to_list(page, list)) put_swap_page(page, entry);
goto retry;
return 0; return 0;
} }
......
...@@ -1125,8 +1125,23 @@ static unsigned long shrink_page_list(struct list_head *page_list, ...@@ -1125,8 +1125,23 @@ static unsigned long shrink_page_list(struct list_head *page_list,
!PageSwapCache(page)) { !PageSwapCache(page)) {
if (!(sc->gfp_mask & __GFP_IO)) if (!(sc->gfp_mask & __GFP_IO))
goto keep_locked; goto keep_locked;
if (!add_to_swap(page, page_list)) if (!add_to_swap(page)) {
if (!PageTransHuge(page))
goto activate_locked;
/* Split THP and swap individual base pages */
if (split_huge_page_to_list(page, page_list))
goto activate_locked;
if (!add_to_swap(page))
goto activate_locked;
}
/* XXX: We don't support THP writes */
if (PageTransHuge(page) &&
split_huge_page_to_list(page, page_list)) {
delete_from_swap_cache(page);
goto activate_locked; goto activate_locked;
}
may_enter_fs = 1; may_enter_fs = 1;
/* Adding to swap updated mapping */ /* Adding to swap updated mapping */
......
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