diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/swapfile.c | 155 |
1 files changed, 94 insertions, 61 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index e73b5441055b..8b5bd34b1a00 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -942,35 +942,34 @@ static struct swap_info_struct *swap_info_get(swp_entry_t entry) return p; } -static unsigned char swap_entry_free(struct swap_info_struct *p, - swp_entry_t entry, unsigned char usage, - bool swap_info_locked) +static struct swap_info_struct *swap_info_get_cont(swp_entry_t entry, + struct swap_info_struct *q) +{ + struct swap_info_struct *p; + + p = _swap_info_get(entry); + + if (p != q) { + if (q != NULL) + spin_unlock(&q->lock); + if (p != NULL) + spin_lock(&p->lock); + } + return p; +} + +static unsigned char __swap_entry_free(struct swap_info_struct *p, + swp_entry_t entry, unsigned char usage) { struct swap_cluster_info *ci; unsigned long offset = swp_offset(entry); unsigned char count; unsigned char has_cache; - bool lock_swap_info = false; - - if (!swap_info_locked) { - count = p->swap_map[offset]; - if (!p->cluster_info || count == usage || count == SWAP_MAP_SHMEM) { -lock_swap_info: - swap_info_locked = true; - lock_swap_info = true; - spin_lock(&p->lock); - } - } - ci = lock_cluster(p, offset); + ci = lock_cluster_or_swap_info(p, offset); count = p->swap_map[offset]; - if (!swap_info_locked && (count == usage || count == SWAP_MAP_SHMEM)) { - unlock_cluster(ci); - goto lock_swap_info; - } - has_cache = count & SWAP_HAS_CACHE; count &= ~SWAP_HAS_CACHE; @@ -994,46 +993,52 @@ lock_swap_info: } usage = count | has_cache; - p->swap_map[offset] = usage; + p->swap_map[offset] = usage ? : SWAP_HAS_CACHE; + + unlock_cluster_or_swap_info(p, ci); + + return usage; +} +static void swap_entry_free(struct swap_info_struct *p, swp_entry_t entry) +{ + struct swap_cluster_info *ci; + unsigned long offset = swp_offset(entry); + unsigned char count; + + ci = lock_cluster(p, offset); + count = p->swap_map[offset]; + VM_BUG_ON(count != SWAP_HAS_CACHE); + p->swap_map[offset] = 0; + dec_cluster_info_page(p, p->cluster_info, offset); unlock_cluster(ci); - /* free if no reference */ - if (!usage) { - VM_BUG_ON(!swap_info_locked); - mem_cgroup_uncharge_swap(entry); - ci = lock_cluster(p, offset); - dec_cluster_info_page(p, p->cluster_info, offset); - unlock_cluster(ci); - if (offset < p->lowest_bit) - p->lowest_bit = offset; - if (offset > p->highest_bit) { - bool was_full = !p->highest_bit; - p->highest_bit = offset; - if (was_full && (p->flags & SWP_WRITEOK)) { - spin_lock(&swap_avail_lock); - WARN_ON(!plist_node_empty(&p->avail_list)); - if (plist_node_empty(&p->avail_list)) - plist_add(&p->avail_list, - &swap_avail_head); - spin_unlock(&swap_avail_lock); - } - } - atomic_long_inc(&nr_swap_pages); - p->inuse_pages--; - frontswap_invalidate_page(p->type, offset); - if (p->flags & SWP_BLKDEV) { - struct gendisk *disk = p->bdev->bd_disk; - if (disk->fops->swap_slot_free_notify) - disk->fops->swap_slot_free_notify(p->bdev, - offset); + mem_cgroup_uncharge_swap(entry); + if (offset < p->lowest_bit) + p->lowest_bit = offset; + if (offset > p->highest_bit) { + bool was_full = !p->highest_bit; + + p->highest_bit = offset; + if (was_full && (p->flags & SWP_WRITEOK)) { + spin_lock(&swap_avail_lock); + WARN_ON(!plist_node_empty(&p->avail_list)); + if (plist_node_empty(&p->avail_list)) + plist_add(&p->avail_list, + &swap_avail_head); + spin_unlock(&swap_avail_lock); } } + atomic_long_inc(&nr_swap_pages); + p->inuse_pages--; + frontswap_invalidate_page(p->type, offset); + if (p->flags & SWP_BLKDEV) { + struct gendisk *disk = p->bdev->bd_disk; - if (lock_swap_info) - spin_unlock(&p->lock); - - return usage; + if (disk->fops->swap_slot_free_notify) + disk->fops->swap_slot_free_notify(p->bdev, + offset); + } } /* @@ -1045,8 +1050,10 @@ void swap_free(swp_entry_t entry) struct swap_info_struct *p; p = _swap_info_get(entry); - if (p) - swap_entry_free(p, entry, 1, false); + if (p) { + if (!__swap_entry_free(p, entry, 1)) + swapcache_free_entries(&entry, 1); + } } /* @@ -1057,8 +1064,32 @@ void swapcache_free(swp_entry_t entry) struct swap_info_struct *p; p = _swap_info_get(entry); + if (p) { + if (!__swap_entry_free(p, entry, SWAP_HAS_CACHE)) + swapcache_free_entries(&entry, 1); + } +} + +void swapcache_free_entries(swp_entry_t *entries, int n) +{ + struct swap_info_struct *p, *prev; + int i; + + if (n <= 0) + return; + + prev = NULL; + p = NULL; + for (i = 0; i < n; ++i) { + p = swap_info_get_cont(entries[i], prev); + if (p) + swap_entry_free(p, entries[i]); + else + break; + prev = p; + } if (p) - swap_entry_free(p, entry, SWAP_HAS_CACHE, false); + spin_unlock(&p->lock); } /* @@ -1241,21 +1272,23 @@ int free_swap_and_cache(swp_entry_t entry) { struct swap_info_struct *p; struct page *page = NULL; + unsigned char count; if (non_swap_entry(entry)) return 1; - p = swap_info_get(entry); + p = _swap_info_get(entry); if (p) { - if (swap_entry_free(p, entry, 1, true) == SWAP_HAS_CACHE) { + count = __swap_entry_free(p, entry, 1); + if (count == SWAP_HAS_CACHE) { page = find_get_page(swap_address_space(entry), swp_offset(entry)); if (page && !trylock_page(page)) { put_page(page); page = NULL; } - } - spin_unlock(&p->lock); + } else if (!count) + swapcache_free_entries(&entry, 1); } if (page) { /* |