#include <linux/swapfile.h>
#include <linux/export.h>
#include <linux/swap_slots.h>
+#include <linux/sort.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
}
}
+#ifdef CONFIG_THP_SWAP
+#define SWAPFILE_CLUSTER HPAGE_PMD_NR
+#else
#define SWAPFILE_CLUSTER 256
+#endif
#define LATENCY_LIMIT 256
static inline void cluster_set_flag(struct swap_cluster_info *info,
schedule_work(&si->discard_work);
}
+static void __free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info;
+
+ cluster_set_flag(ci + idx, CLUSTER_FLAG_FREE);
+ cluster_list_add_tail(&si->free_clusters, ci, idx);
+}
+
/*
* Doing discard actually. After a cluster discard is finished, the cluster
* will be added to free cluster list. caller should hold si->lock.
spin_lock(&si->lock);
ci = lock_cluster(si, idx * SWAPFILE_CLUSTER);
- cluster_set_flag(ci, CLUSTER_FLAG_FREE);
- unlock_cluster(ci);
- cluster_list_add_tail(&si->free_clusters, info, idx);
- ci = lock_cluster(si, idx * SWAPFILE_CLUSTER);
+ __free_cluster(si, idx);
memset(si->swap_map + idx * SWAPFILE_CLUSTER,
0, SWAPFILE_CLUSTER);
unlock_cluster(ci);
spin_unlock(&si->lock);
}
+static void alloc_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info;
+
+ VM_BUG_ON(cluster_list_first(&si->free_clusters) != idx);
+ cluster_list_del_first(&si->free_clusters, ci);
+ cluster_set_count_flag(ci + idx, 0, 0);
+}
+
+static void free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info + idx;
+
+ VM_BUG_ON(cluster_count(ci) != 0);
+ /*
+ * If the swap is discardable, prepare discard the cluster
+ * instead of free it immediately. The cluster will be freed
+ * after discard.
+ */
+ if ((si->flags & (SWP_WRITEOK | SWP_PAGE_DISCARD)) ==
+ (SWP_WRITEOK | SWP_PAGE_DISCARD)) {
+ swap_cluster_schedule_discard(si, idx);
+ return;
+ }
+
+ __free_cluster(si, idx);
+}
+
/*
* The cluster corresponding to page_nr will be used. The cluster will be
* removed from free cluster list and its usage counter will be increased.
if (!cluster_info)
return;
- if (cluster_is_free(&cluster_info[idx])) {
- VM_BUG_ON(cluster_list_first(&p->free_clusters) != idx);
- cluster_list_del_first(&p->free_clusters, cluster_info);
- cluster_set_count_flag(&cluster_info[idx], 0, 0);
- }
+ if (cluster_is_free(&cluster_info[idx]))
+ alloc_cluster(p, idx);
VM_BUG_ON(cluster_count(&cluster_info[idx]) >= SWAPFILE_CLUSTER);
cluster_set_count(&cluster_info[idx],
cluster_set_count(&cluster_info[idx],
cluster_count(&cluster_info[idx]) - 1);
- if (cluster_count(&cluster_info[idx]) == 0) {
- /*
- * If the swap is discardable, prepare discard the cluster
- * instead of free it immediately. The cluster will be freed
- * after discard.
- */
- if ((p->flags & (SWP_WRITEOK | SWP_PAGE_DISCARD)) ==
- (SWP_WRITEOK | SWP_PAGE_DISCARD)) {
- swap_cluster_schedule_discard(p, idx);
- return;
- }
-
- cluster_set_flag(&cluster_info[idx], CLUSTER_FLAG_FREE);
- cluster_list_add_tail(&p->free_clusters, cluster_info, idx);
- }
+ if (cluster_count(&cluster_info[idx]) == 0)
+ free_cluster(p, idx);
}
/*
return found_free;
}
+static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
+ unsigned int nr_entries)
+{
+ unsigned int end = offset + nr_entries - 1;
+
+ if (offset == si->lowest_bit)
+ si->lowest_bit += nr_entries;
+ if (end == si->highest_bit)
+ si->highest_bit -= nr_entries;
+ si->inuse_pages += nr_entries;
+ if (si->inuse_pages == si->pages) {
+ si->lowest_bit = si->max;
+ si->highest_bit = 0;
+ spin_lock(&swap_avail_lock);
+ plist_del(&si->avail_list, &swap_avail_head);
+ spin_unlock(&swap_avail_lock);
+ }
+}
+
+static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
+ unsigned int nr_entries)
+{
+ unsigned long end = offset + nr_entries - 1;
+ void (*swap_slot_free_notify)(struct block_device *, unsigned long);
+
+ if (offset < si->lowest_bit)
+ si->lowest_bit = offset;
+ if (end > si->highest_bit) {
+ bool was_full = !si->highest_bit;
+
+ si->highest_bit = end;
+ if (was_full && (si->flags & SWP_WRITEOK)) {
+ spin_lock(&swap_avail_lock);
+ WARN_ON(!plist_node_empty(&si->avail_list));
+ if (plist_node_empty(&si->avail_list))
+ plist_add(&si->avail_list, &swap_avail_head);
+ spin_unlock(&swap_avail_lock);
+ }
+ }
+ atomic_long_add(nr_entries, &nr_swap_pages);
+ si->inuse_pages -= nr_entries;
+ if (si->flags & SWP_BLKDEV)
+ swap_slot_free_notify =
+ si->bdev->bd_disk->fops->swap_slot_free_notify;
+ else
+ swap_slot_free_notify = NULL;
+ while (offset <= end) {
+ frontswap_invalidate_page(si->type, offset);
+ if (swap_slot_free_notify)
+ swap_slot_free_notify(si->bdev, offset);
+ offset++;
+ }
+}
+
static int scan_swap_map_slots(struct swap_info_struct *si,
unsigned char usage, int nr,
swp_entry_t slots[])
inc_cluster_info_page(si, si->cluster_info, offset);
unlock_cluster(ci);
- if (offset == si->lowest_bit)
- si->lowest_bit++;
- if (offset == si->highest_bit)
- si->highest_bit--;
- si->inuse_pages++;
- if (si->inuse_pages == si->pages) {
- si->lowest_bit = si->max;
- si->highest_bit = 0;
- spin_lock(&swap_avail_lock);
- plist_del(&si->avail_list, &swap_avail_head);
- spin_unlock(&swap_avail_lock);
- }
+ swap_range_alloc(si, offset, 1);
si->cluster_next = offset + 1;
slots[n_ret++] = swp_entry(si->type, offset);
return n_ret;
}
+#ifdef CONFIG_THP_SWAP
+static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
+{
+ unsigned long idx;
+ struct swap_cluster_info *ci;
+ unsigned long offset, i;
+ unsigned char *map;
+
+ if (cluster_list_empty(&si->free_clusters))
+ return 0;
+
+ idx = cluster_list_first(&si->free_clusters);
+ offset = idx * SWAPFILE_CLUSTER;
+ ci = lock_cluster(si, offset);
+ alloc_cluster(si, idx);
+ cluster_set_count_flag(ci, SWAPFILE_CLUSTER, 0);
+
+ map = si->swap_map + offset;
+ for (i = 0; i < SWAPFILE_CLUSTER; i++)
+ map[i] = SWAP_HAS_CACHE;
+ unlock_cluster(ci);
+ swap_range_alloc(si, offset, SWAPFILE_CLUSTER);
+ *slot = swp_entry(si->type, offset);
+
+ return 1;
+}
+
+static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ unsigned long offset = idx * SWAPFILE_CLUSTER;
+ struct swap_cluster_info *ci;
+
+ ci = lock_cluster(si, offset);
+ cluster_set_count_flag(ci, 0, 0);
+ free_cluster(si, idx);
+ unlock_cluster(ci);
+ swap_range_free(si, offset, SWAPFILE_CLUSTER);
+}
+#else
+static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
+{
+ VM_WARN_ON_ONCE(1);
+ return 0;
+}
+#endif /* CONFIG_THP_SWAP */
+
static unsigned long scan_swap_map(struct swap_info_struct *si,
unsigned char usage)
{
}
-int get_swap_pages(int n_goal, swp_entry_t swp_entries[])
+int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
{
+ unsigned long nr_pages = cluster ? SWAPFILE_CLUSTER : 1;
struct swap_info_struct *si, *next;
long avail_pgs;
int n_ret = 0;
- avail_pgs = atomic_long_read(&nr_swap_pages);
+ /* Only single cluster request supported */
+ WARN_ON_ONCE(n_goal > 1 && cluster);
+
+ avail_pgs = atomic_long_read(&nr_swap_pages) / nr_pages;
if (avail_pgs <= 0)
goto noswap;
if (n_goal > avail_pgs)
n_goal = avail_pgs;
- atomic_long_sub(n_goal, &nr_swap_pages);
+ atomic_long_sub(n_goal * nr_pages, &nr_swap_pages);
spin_lock(&swap_avail_lock);
spin_unlock(&si->lock);
goto nextsi;
}
- n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
- n_goal, swp_entries);
+ if (cluster)
+ n_ret = swap_alloc_cluster(si, swp_entries);
+ else
+ n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
+ n_goal, swp_entries);
spin_unlock(&si->lock);
- if (n_ret)
+ if (n_ret || cluster)
goto check_out;
pr_debug("scan_swap_map of si %d failed to find offset\n",
si->type);
check_out:
if (n_ret < n_goal)
- atomic_long_add((long) (n_goal-n_ret), &nr_swap_pages);
+ atomic_long_add((long)(n_goal - n_ret) * nr_pages,
+ &nr_swap_pages);
noswap:
return n_ret;
}
dec_cluster_info_page(p, p->cluster_info, offset);
unlock_cluster(ci);
- 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 (disk->fops->swap_slot_free_notify)
- disk->fops->swap_slot_free_notify(p->bdev,
- offset);
- }
+ mem_cgroup_uncharge_swap(entry, 1);
+ swap_range_free(p, offset, 1);
}
/*
/*
* Called after dropping swapcache to decrease refcnt to swap entries.
*/
-void swapcache_free(swp_entry_t entry)
+static void swapcache_free(swp_entry_t entry)
{
struct swap_info_struct *p;
}
}
+#ifdef CONFIG_THP_SWAP
+static void swapcache_free_cluster(swp_entry_t entry)
+{
+ unsigned long offset = swp_offset(entry);
+ unsigned long idx = offset / SWAPFILE_CLUSTER;
+ struct swap_cluster_info *ci;
+ struct swap_info_struct *si;
+ unsigned char *map;
+ unsigned int i;
+
+ si = swap_info_get(entry);
+ if (!si)
+ return;
+
+ ci = lock_cluster(si, offset);
+ map = si->swap_map + offset;
+ for (i = 0; i < SWAPFILE_CLUSTER; i++) {
+ VM_BUG_ON(map[i] != SWAP_HAS_CACHE);
+ map[i] = 0;
+ }
+ unlock_cluster(ci);
+ mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER);
+ swap_free_cluster(si, idx);
+ spin_unlock(&si->lock);
+}
+#else
+static inline void swapcache_free_cluster(swp_entry_t entry)
+{
+}
+#endif /* CONFIG_THP_SWAP */
+
+void put_swap_page(struct page *page, swp_entry_t entry)
+{
+ if (!PageTransHuge(page))
+ swapcache_free(entry);
+ else
+ swapcache_free_cluster(entry);
+}
+
+static int swp_entry_cmp(const void *ent1, const void *ent2)
+{
+ const swp_entry_t *e1 = ent1, *e2 = ent2;
+
+ return (int)swp_type(*e1) - (int)swp_type(*e2);
+}
+
void swapcache_free_entries(swp_entry_t *entries, int n)
{
struct swap_info_struct *p, *prev;
prev = NULL;
p = NULL;
+
+ /*
+ * Sort swap entries by swap device, so each lock is only taken once.
+ * nr_swapfiles isn't absolutely correct, but the overhead of sort() is
+ * so low that it isn't necessary to optimize further.
+ */
+ if (nr_swapfiles > 1)
+ sort(entries, n, sizeof(entries[0]), swp_entry_cmp, NULL);
for (i = 0; i < n; ++i) {
p = swap_info_get_cont(entries[i], prev);
if (p)
swap_map = &si->swap_map[i];
entry = swp_entry(type, i);
page = read_swap_cache_async(entry,
- GFP_HIGHUSER_MOVABLE, NULL, 0);
+ GFP_HIGHUSER_MOVABLE, NULL, 0, false);
if (!page) {
/*
* Either swap_duplicate() failed because entry
projects / karo-tx-linux.git / blobdiff