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-rw-r--r--mm/zswap.c78
1 files changed, 40 insertions, 38 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index d7337fbf6605..aeaef0fb5624 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -89,6 +89,9 @@ static unsigned int zswap_max_pool_percent = 20;
module_param_named(max_pool_percent,
zswap_max_pool_percent, uint, 0644);
+/* zbud_pool is shared by all of zswap backend */
+static struct zbud_pool *zswap_pool;
+
/*********************************
* compression functions
**********************************/
@@ -160,14 +163,14 @@ static void zswap_comp_exit(void)
* rbnode - links the entry into red-black tree for the appropriate swap type
* refcount - the number of outstanding reference to the entry. This is needed
* to protect against premature freeing of the entry by code
- * concurent calls to load, invalidate, and writeback. The lock
+ * concurrent calls to load, invalidate, and writeback. The lock
* for the zswap_tree structure that contains the entry must
* be held while changing the refcount. Since the lock must
* be held, there is no reason to also make refcount atomic.
* offset - the swap offset for the entry. Index into the red-black tree.
- * handle - zsmalloc allocation handle that stores the compressed page data
+ * handle - zbud allocation handle that stores the compressed page data
* length - the length in bytes of the compressed page data. Needed during
- * decompression
+ * decompression
*/
struct zswap_entry {
struct rb_node rbnode;
@@ -189,7 +192,6 @@ struct zswap_header {
struct zswap_tree {
struct rb_root rbroot;
spinlock_t lock;
- struct zbud_pool *pool;
};
static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
@@ -202,7 +204,7 @@ static struct kmem_cache *zswap_entry_cache;
static int zswap_entry_cache_create(void)
{
zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
- return (zswap_entry_cache == NULL);
+ return zswap_entry_cache == NULL;
}
static void zswap_entry_cache_destory(void)
@@ -282,16 +284,15 @@ static void zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
}
/*
- * Carries out the common pattern of freeing and entry's zsmalloc allocation,
+ * Carries out the common pattern of freeing and entry's zbud allocation,
* freeing the entry itself, and decrementing the number of stored pages.
*/
-static void zswap_free_entry(struct zswap_tree *tree,
- struct zswap_entry *entry)
+static void zswap_free_entry(struct zswap_entry *entry)
{
- zbud_free(tree->pool, entry->handle);
+ zbud_free(zswap_pool, entry->handle);
zswap_entry_cache_free(entry);
atomic_dec(&zswap_stored_pages);
- zswap_pool_pages = zbud_get_pool_size(tree->pool);
+ zswap_pool_pages = zbud_get_pool_size(zswap_pool);
}
/* caller must hold the tree lock */
@@ -311,7 +312,7 @@ static void zswap_entry_put(struct zswap_tree *tree,
BUG_ON(refcount < 0);
if (refcount == 0) {
zswap_rb_erase(&tree->rbroot, entry);
- zswap_free_entry(tree, entry);
+ zswap_free_entry(entry);
}
}
@@ -407,8 +408,8 @@ cleanup:
**********************************/
static bool zswap_is_full(void)
{
- return (totalram_pages * zswap_max_pool_percent / 100 <
- zswap_pool_pages);
+ return totalram_pages * zswap_max_pool_percent / 100 <
+ zswap_pool_pages;
}
/*********************************
@@ -545,7 +546,6 @@ static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
zbud_unmap(pool, handle);
tree = zswap_trees[swp_type(swpentry)];
offset = swp_offset(swpentry);
- BUG_ON(pool != tree->pool);
/* find and ref zswap entry */
spin_lock(&tree->lock);
@@ -573,13 +573,13 @@ static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle)
case ZSWAP_SWAPCACHE_NEW: /* page is locked */
/* decompress */
dlen = PAGE_SIZE;
- src = (u8 *)zbud_map(tree->pool, entry->handle) +
+ src = (u8 *)zbud_map(zswap_pool, entry->handle) +
sizeof(struct zswap_header);
dst = kmap_atomic(page);
ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src,
entry->length, dst, &dlen);
kunmap_atomic(dst);
- zbud_unmap(tree->pool, entry->handle);
+ zbud_unmap(zswap_pool, entry->handle);
BUG_ON(ret);
BUG_ON(dlen != PAGE_SIZE);
@@ -652,7 +652,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
/* reclaim space if needed */
if (zswap_is_full()) {
zswap_pool_limit_hit++;
- if (zbud_reclaim_page(tree->pool, 8)) {
+ if (zbud_reclaim_page(zswap_pool, 8)) {
zswap_reject_reclaim_fail++;
ret = -ENOMEM;
goto reject;
@@ -679,7 +679,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
/* store */
len = dlen + sizeof(struct zswap_header);
- ret = zbud_alloc(tree->pool, len, __GFP_NORETRY | __GFP_NOWARN,
+ ret = zbud_alloc(zswap_pool, len, __GFP_NORETRY | __GFP_NOWARN,
&handle);
if (ret == -ENOSPC) {
zswap_reject_compress_poor++;
@@ -689,11 +689,11 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
zswap_reject_alloc_fail++;
goto freepage;
}
- zhdr = zbud_map(tree->pool, handle);
+ zhdr = zbud_map(zswap_pool, handle);
zhdr->swpentry = swp_entry(type, offset);
buf = (u8 *)(zhdr + 1);
memcpy(buf, dst, dlen);
- zbud_unmap(tree->pool, handle);
+ zbud_unmap(zswap_pool, handle);
put_cpu_var(zswap_dstmem);
/* populate entry */
@@ -716,7 +716,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
/* update stats */
atomic_inc(&zswap_stored_pages);
- zswap_pool_pages = zbud_get_pool_size(tree->pool);
+ zswap_pool_pages = zbud_get_pool_size(zswap_pool);
return 0;
@@ -752,13 +752,13 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
/* decompress */
dlen = PAGE_SIZE;
- src = (u8 *)zbud_map(tree->pool, entry->handle) +
+ src = (u8 *)zbud_map(zswap_pool, entry->handle) +
sizeof(struct zswap_header);
dst = kmap_atomic(page);
ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src, entry->length,
dst, &dlen);
kunmap_atomic(dst);
- zbud_unmap(tree->pool, entry->handle);
+ zbud_unmap(zswap_pool, entry->handle);
BUG_ON(ret);
spin_lock(&tree->lock);
@@ -804,11 +804,9 @@ static void zswap_frontswap_invalidate_area(unsigned type)
/* walk the tree and free everything */
spin_lock(&tree->lock);
rbtree_postorder_for_each_entry_safe(entry, n, &tree->rbroot, rbnode)
- zswap_free_entry(tree, entry);
+ zswap_free_entry(entry);
tree->rbroot = RB_ROOT;
spin_unlock(&tree->lock);
-
- zbud_destroy_pool(tree->pool);
kfree(tree);
zswap_trees[type] = NULL;
}
@@ -822,20 +820,14 @@ static void zswap_frontswap_init(unsigned type)
struct zswap_tree *tree;
tree = kzalloc(sizeof(struct zswap_tree), GFP_KERNEL);
- if (!tree)
- goto err;
- tree->pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
- if (!tree->pool)
- goto freetree;
+ if (!tree) {
+ pr_err("alloc failed, zswap disabled for swap type %d\n", type);
+ return;
+ }
+
tree->rbroot = RB_ROOT;
spin_lock_init(&tree->lock);
zswap_trees[type] = tree;
- return;
-
-freetree:
- kfree(tree);
-err:
- pr_err("alloc failed, zswap disabled for swap type %d\n", type);
}
static struct frontswap_ops zswap_frontswap_ops = {
@@ -907,9 +899,16 @@ static int __init init_zswap(void)
return 0;
pr_info("loading zswap\n");
+
+ zswap_pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
+ if (!zswap_pool) {
+ pr_err("zbud pool creation failed\n");
+ goto error;
+ }
+
if (zswap_entry_cache_create()) {
pr_err("entry cache creation failed\n");
- goto error;
+ goto cachefail;
}
if (zswap_comp_init()) {
pr_err("compressor initialization failed\n");
@@ -919,6 +918,7 @@ static int __init init_zswap(void)
pr_err("per-cpu initialization failed\n");
goto pcpufail;
}
+
frontswap_register_ops(&zswap_frontswap_ops);
if (zswap_debugfs_init())
pr_warn("debugfs initialization failed\n");
@@ -927,6 +927,8 @@ pcpufail:
zswap_comp_exit();
compfail:
zswap_entry_cache_destory();
+cachefail:
+ zbud_destroy_pool(zswap_pool);
error:
return -ENOMEM;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 11:24:50 +0000