[Devel] [PATCH vz9 1/5] mm/swap: activate swapped in pages on fault

[Nikita Yushchenko]

From: Andrey Ryabinin <aryabinin at virtuozzo.com>

Move swapped in anon pages directly to active list. This should
help us to prevent anon thrashing. Recently swapped in pages
has more chances to stay in memory.

https://pmc.acronis.com/browse/VSTOR-20859
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
[VvS RHEL7.8 rebase] context changes

(cherry picked from vz7 commit 134cd9b20a914080539e6310f76fe3f7b32bc710)
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
Reviewed-by: Andrey Ryabinin <aryabinin at virtuozzo.com>

(cherry-picked from vz8 commit 529114b7d628 ("mm/swap: activate
swapped in pages on fault"))

Signed-off-by: Nikita Yushchenko <nikita.yushchenko at virtuozzo.com>
---
 include/linux/swap.h |  4 ++--
 mm/madvise.c         |  4 ++--
 mm/swap_state.c      | 19 ++++++++++++-------
 mm/zswap.c           |  2 +-
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 9cf14021d01a..68c186361397 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -460,10 +460,10 @@ extern struct page *lookup_swap_cache(swp_entry_t entry,
 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
 extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
 			struct vm_area_struct *vma, unsigned long addr,
-			bool do_poll);
+			bool do_poll, bool activate);
 extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t,
 			struct vm_area_struct *vma, unsigned long addr,
-			bool *new_page_allocated);
+			bool *new_page_allocated, bool activate);
 extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
 				struct vm_fault *vmf);
 extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
diff --git a/mm/madvise.c b/mm/madvise.c
index 5c065bc8b5f6..ac42b1d12f7f 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -211,7 +211,7 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
 			continue;
 
 		page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE,
-							vma, index, false);
+					     vma, index, false, false);
 		if (page)
 			put_page(page);
 	}
@@ -242,7 +242,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
 
 		swap = radix_to_swp_entry(page);
 		page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
-							NULL, 0, false);
+					     NULL, 0, false, false);
 		if (page)
 			put_page(page);
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 504fed0107da..7e3104d27d4f 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -412,7 +412,7 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
 
 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 			struct vm_area_struct *vma, unsigned long addr,
-			bool *new_page_allocated)
+			bool *new_page_allocated, bool activate)
 {
 	struct swap_info_struct *si;
 	struct page *page;
@@ -497,6 +497,8 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		workingset_refault(page, shadow);
 
 	/* Caller will initiate read into locked page */
+	if (activate)
+		SetPageActive(page);
 	lru_cache_add(page);
 	*new_page_allocated = true;
 	return page;
@@ -515,11 +517,12 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
  * the swap entry is no longer in use.
  */
 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
-		struct vm_area_struct *vma, unsigned long addr, bool do_poll)
+		struct vm_area_struct *vma, unsigned long addr, bool do_poll,
+		bool activate)
 {
 	bool page_was_allocated;
 	struct page *retpage = __read_swap_cache_async(entry, gfp_mask,
-			vma, addr, &page_was_allocated);
+			vma, addr, &page_was_allocated, activate);
 
 	if (page_was_allocated)
 		swap_readpage(retpage, do_poll);
@@ -638,7 +641,7 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 		/* Ok, do the async read-ahead now */
 		page = __read_swap_cache_async(
 			swp_entry(swp_type(entry), offset),
-			gfp_mask, vma, addr, &page_allocated);
+			gfp_mask, vma, addr, &page_allocated, offset == entry_offset);
 		if (!page)
 			continue;
 		if (page_allocated) {
@@ -654,7 +657,8 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 
 	lru_add_drain();	/* Push any new pages onto the LRU now */
 skip:
-	return read_swap_cache_async(entry, gfp_mask, vma, addr, do_poll);
+	return read_swap_cache_async(entry, gfp_mask, vma, addr, do_poll,
+				     true);
 }
 
 int init_swap_address_space(unsigned int type, unsigned long nr_pages)
@@ -811,7 +815,8 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
 		if (unlikely(non_swap_entry(entry)))
 			continue;
 		page = __read_swap_cache_async(entry, gfp_mask, vma,
-					       vmf->address, &page_allocated);
+					       vmf->address, &page_allocated,
+					       i == ra_info.offset);
 		if (!page)
 			continue;
 		if (page_allocated) {
@@ -827,7 +832,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
 	lru_add_drain();
 skip:
 	return read_swap_cache_async(fentry, gfp_mask, vma, vmf->address,
-				     ra_info.win == 1);
+				     ra_info.win == 1, true);
 }
 
 /**
diff --git a/mm/zswap.c b/mm/zswap.c
index 7944e3e57e78..564ff0d6ed3f 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -904,7 +904,7 @@ static int zswap_get_swap_cache_page(swp_entry_t entry,
 	bool page_was_allocated;
 
 	*retpage = __read_swap_cache_async(entry, GFP_KERNEL,
-			NULL, 0, &page_was_allocated);
+			NULL, 0, &page_was_allocated, false);
 	if (page_was_allocated)
 		return ZSWAP_SWAPCACHE_NEW;
 	if (!*retpage)
-- 
2.30.2