return ret;
}
+/* returnes 1 if swap entry is freed */
+static int
+__try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset)
+{
+ int type = si - swap_info;
+ swp_entry_t entry = swp_entry(type, offset);
+ struct page *page;
+ int ret = 0;
+
+ page = find_get_page(&swapper_space, entry.val);
+ if (!page)
+ return 0;
+ /*
+ * This function is called from scan_swap_map() and it's called
+ * by vmscan.c at reclaiming pages. So, we hold a lock on a page, here.
+ * We have to use trylock for avoiding deadlock. This is a special
+ * case and you should use try_to_free_swap() with explicit lock_page()
+ * in usual operations.
+ */
+ if (trylock_page(page)) {
+ ret = try_to_free_swap(page);
+ unlock_page(page);
+ }
+ page_cache_release(page);
+ return ret;
+}
/*
* We need this because the bdev->unplug_fn can sleep and we cannot
}
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL);
+ nr_blocks, GFP_KERNEL,
+ DISCARD_FL_BARRIER);
if (err)
break;
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO))
+ nr_blocks, GFP_NOIO,
+ DISCARD_FL_BARRIER))
break;
}
goto no_page;
if (offset > si->highest_bit)
scan_base = offset = si->lowest_bit;
+
+ /* reuse swap entry of cache-only swap if not busy. */
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ int swap_was_freed;
+ spin_unlock(&swap_lock);
+ swap_was_freed = __try_to_reclaim_swap(si, offset);
+ spin_lock(&swap_lock);
+ /* entry was freed successfully, try to use this again */
+ if (swap_was_freed)
+ goto checks;
+ goto scan; /* check next one */
+ }
+
if (si->swap_map[offset])
goto scan;
spin_lock(&swap_lock);
goto checks;
}
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
if (unlikely(--latency_ration < 0)) {
cond_resched();
latency_ration = LATENCY_LIMIT;
spin_lock(&swap_lock);
goto checks;
}
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
if (unlikely(--latency_ration < 0)) {
cond_resched();
latency_ration = LATENCY_LIMIT;
swap_list.next = p - swap_info;
nr_swap_pages++;
p->inuse_pages--;
- mem_cgroup_uncharge_swap(ent);
}
+ if (!swap_count(count))
+ mem_cgroup_uncharge_swap(ent);
return count;
}
void swapcache_free(swp_entry_t entry, struct page *page)
{
struct swap_info_struct *p;
+ int ret;
- if (page)
- mem_cgroup_uncharge_swapcache(page, entry);
p = swap_info_get(entry);
if (p) {
- swap_entry_free(p, entry, SWAP_CACHE);
+ ret = swap_entry_free(p, entry, SWAP_CACHE);
+ if (page) {
+ bool swapout;
+ if (ret)
+ swapout = true; /* the end of swap out */
+ else
+ swapout = false; /* no more swap users! */
+ mem_cgroup_uncharge_swapcache(page, entry, swapout);
+ }
spin_unlock(&swap_lock);
}
return;
struct swap_info_struct *p;
struct page *page = NULL;
- if (is_migration_entry(entry))
+ if (non_swap_entry(entry))
return 1;
p = swap_info_get(entry);
if (!bdev) {
if (bdev_p)
- *bdev_p = bdget(sis->bdev->bd_dev);
+ *bdev_p = bdgrab(sis->bdev);
spin_unlock(&swap_lock);
return i;
struct swap_extent, list);
if (se->start_block == offset) {
if (bdev_p)
- *bdev_p = bdget(sis->bdev->bd_dev);
+ *bdev_p = bdgrab(sis->bdev);
spin_unlock(&swap_lock);
bdput(bdev);
p->flags &= ~SWP_WRITEOK;
spin_unlock(&swap_lock);
- current->flags |= PF_SWAPOFF;
+ current->flags |= PF_OOM_ORIGIN;
err = try_to_unuse(type);
- current->flags &= ~PF_SWAPOFF;
+ current->flags &= ~PF_OOM_ORIGIN;
if (err) {
/* re-insert swap space back into swap_list */
goto bad_swap;
}
- if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
- p->flags |= SWP_SOLIDSTATE;
- p->cluster_next = 1 + (random32() % p->highest_bit);
+ if (p->bdev) {
+ if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
+ p->flags |= SWP_SOLIDSTATE;
+ p->cluster_next = 1 + (random32() % p->highest_bit);
+ }
+ if (discard_swap(p) == 0)
+ p->flags |= SWP_DISCARDABLE;
}
- if (discard_swap(p) == 0)
- p->flags |= SWP_DISCARDABLE;
mutex_lock(&swapon_mutex);
spin_lock(&swap_lock);
int count;
bool has_cache;
- if (is_migration_entry(entry))
+ if (non_swap_entry(entry))
return -EINVAL;
type = swp_type(entry);