diff options
| -rw-r--r-- | include/linux/swap.h | 1 | ||||
| -rw-r--r-- | mm/swapfile.c | 78 |
2 files changed, 72 insertions, 7 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index d83d28e53e62..964b4f1fba4a 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -188,6 +188,7 @@ struct swap_cluster_info { }; #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ +#define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ /* * We assign a cluster to each CPU, so each CPU can allocate swap entry from diff --git a/mm/swapfile.c b/mm/swapfile.c index c32e9b23d642..164d9624d7d2 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -265,6 +265,16 @@ static inline void cluster_set_null(struct swap_cluster_info *info) info->data = 0; } +static inline bool cluster_is_huge(struct swap_cluster_info *info) +{ + return info->flags & CLUSTER_FLAG_HUGE; +} + +static inline void cluster_clear_huge(struct swap_cluster_info *info) +{ + info->flags &= ~CLUSTER_FLAG_HUGE; +} + static inline struct swap_cluster_info *lock_cluster(struct swap_info_struct *si, unsigned long offset) { @@ -846,7 +856,7 @@ static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot) offset = idx * SWAPFILE_CLUSTER; ci = lock_cluster(si, offset); alloc_cluster(si, idx); - cluster_set_count_flag(ci, SWAPFILE_CLUSTER, 0); + cluster_set_count_flag(ci, SWAPFILE_CLUSTER, CLUSTER_FLAG_HUGE); map = si->swap_map + offset; for (i = 0; i < SWAPFILE_CLUSTER; i++) @@ -1176,6 +1186,7 @@ static void swapcache_free_cluster(swp_entry_t entry) return; ci = lock_cluster(si, offset); + VM_BUG_ON(!cluster_is_huge(ci)); map = si->swap_map + offset; for (i = 0; i < SWAPFILE_CLUSTER; i++) { val = map[i]; @@ -1187,6 +1198,7 @@ static void swapcache_free_cluster(swp_entry_t entry) for (i = 0; i < SWAPFILE_CLUSTER; i++) map[i] &= ~SWAP_HAS_CACHE; } + cluster_clear_huge(ci); unlock_cluster(ci); if (free_entries == SWAPFILE_CLUSTER) { spin_lock(&si->lock); @@ -1350,6 +1362,54 @@ out: return count; } +#ifdef CONFIG_THP_SWAP +static bool swap_page_trans_huge_swapped(struct swap_info_struct *si, + swp_entry_t entry) +{ + struct swap_cluster_info *ci; + unsigned char *map = si->swap_map; + unsigned long roffset = swp_offset(entry); + unsigned long offset = round_down(roffset, SWAPFILE_CLUSTER); + int i; + bool ret = false; + + ci = lock_cluster_or_swap_info(si, offset); + if (!ci || !cluster_is_huge(ci)) { + if (map[roffset] != SWAP_HAS_CACHE) + ret = true; + goto unlock_out; + } + for (i = 0; i < SWAPFILE_CLUSTER; i++) { + if (map[offset + i] != SWAP_HAS_CACHE) { + ret = true; + break; + } + } +unlock_out: + unlock_cluster_or_swap_info(si, ci); + return ret; +} + +static bool page_swapped(struct page *page) +{ + swp_entry_t entry; + struct swap_info_struct *si; + + if (likely(!PageTransCompound(page))) + return page_swapcount(page) != 0; + + page = compound_head(page); + entry.val = page_private(page); + si = _swap_info_get(entry); + if (si) + return swap_page_trans_huge_swapped(si, entry); + return false; +} +#else +#define swap_page_trans_huge_swapped(si, entry) swap_swapcount(si, entry) +#define page_swapped(page) (page_swapcount(page) != 0) +#endif + /* * We can write to an anon page without COW if there are no other references * to it. And as a side-effect, free up its swap: because the old content @@ -1404,7 +1464,7 @@ int try_to_free_swap(struct page *page) return 0; if (PageWriteback(page)) return 0; - if (page_swapcount(page)) + if (page_swapped(page)) return 0; /* @@ -1425,6 +1485,7 @@ int try_to_free_swap(struct page *page) if (pm_suspended_storage()) return 0; + page = compound_head(page); delete_from_swap_cache(page); SetPageDirty(page); return 1; @@ -1446,7 +1507,8 @@ int free_swap_and_cache(swp_entry_t entry) p = _swap_info_get(entry); if (p) { count = __swap_entry_free(p, entry, 1); - if (count == SWAP_HAS_CACHE) { + if (count == SWAP_HAS_CACHE && + !swap_page_trans_huge_swapped(p, entry)) { page = find_get_page(swap_address_space(entry), swp_offset(entry)); if (page && !trylock_page(page)) { @@ -1463,7 +1525,8 @@ int free_swap_and_cache(swp_entry_t entry) */ if (PageSwapCache(page) && !PageWriteback(page) && (!page_mapped(page) || mem_cgroup_swap_full(page)) && - !swap_swapcount(p, entry)) { + !swap_page_trans_huge_swapped(p, entry)) { + page = compound_head(page); delete_from_swap_cache(page); SetPageDirty(page); } @@ -2017,7 +2080,7 @@ int try_to_unuse(unsigned int type, bool frontswap, .sync_mode = WB_SYNC_NONE, }; - swap_writepage(page, &wbc); + swap_writepage(compound_head(page), &wbc); lock_page(page); wait_on_page_writeback(page); } @@ -2030,8 +2093,9 @@ int try_to_unuse(unsigned int type, bool frontswap, * delete, since it may not have been written out to swap yet. */ if (PageSwapCache(page) && - likely(page_private(page) == entry.val)) - delete_from_swap_cache(page); + likely(page_private(page) == entry.val) && + !page_swapped(page)) + delete_from_swap_cache(compound_head(page)); /* * So we could skip searching mms once swap count went |