+++ /dev/null
-/*
- * In-kernel transcendent memory (generic implementation)
- *
- * Copyright (c) 2009-2011, Dan Magenheimer, Oracle Corp.
- *
- * The primary purpose of Transcendent Memory ("tmem") is to map object-oriented
- * "handles" (triples containing a pool id, and object id, and an index), to
- * pages in a page-accessible memory (PAM). Tmem references the PAM pages via
- * an abstract "pampd" (PAM page-descriptor), which can be operated on by a
- * set of functions (pamops). Each pampd contains some representation of
- * PAGE_SIZE bytes worth of data. Tmem must support potentially millions of
- * pages and must be able to insert, find, and delete these pages at a
- * potential frequency of thousands per second concurrently across many CPUs,
- * (and, if used with KVM, across many vcpus across many guests).
- * Tmem is tracked with a hierarchy of data structures, organized by
- * the elements in a handle-tuple: pool_id, object_id, and page index.
- * One or more "clients" (e.g. guests) each provide one or more tmem_pools.
- * Each pool, contains a hash table of rb_trees of tmem_objs. Each
- * tmem_obj contains a radix-tree-like tree of pointers, with intermediate
- * nodes called tmem_objnodes. Each leaf pointer in this tree points to
- * a pampd, which is accessible only through a small set of callbacks
- * registered by the PAM implementation (see tmem_register_pamops). Tmem
- * does all memory allocation via a set of callbacks registered by the tmem
- * host implementation (e.g. see tmem_register_hostops).
- */
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <linux/atomic.h>
-
-#include "tmem.h"
-
-/* data structure sentinels used for debugging... see tmem.h */
-#define POOL_SENTINEL 0x87658765
-#define OBJ_SENTINEL 0x12345678
-#define OBJNODE_SENTINEL 0xfedcba09
-
-/*
- * A tmem host implementation must use this function to register callbacks
- * for memory allocation.
- */
-static struct tmem_hostops tmem_hostops;
-
-static void tmem_objnode_tree_init(void);
-
-void tmem_register_hostops(struct tmem_hostops *m)
-{
- tmem_objnode_tree_init();
- tmem_hostops = *m;
-}
-
-/*
- * A tmem host implementation must use this function to register
- * callbacks for a page-accessible memory (PAM) implementation
- */
-static struct tmem_pamops tmem_pamops;
-
-void tmem_register_pamops(struct tmem_pamops *m)
-{
- tmem_pamops = *m;
-}
-
-/*
- * Oid's are potentially very sparse and tmem_objs may have an indeterminately
- * short life, being added and deleted at a relatively high frequency.
- * So an rb_tree is an ideal data structure to manage tmem_objs. But because
- * of the potentially huge number of tmem_objs, each pool manages a hashtable
- * of rb_trees to reduce search, insert, delete, and rebalancing time.
- * Each hashbucket also has a lock to manage concurrent access.
- *
- * The following routines manage tmem_objs. When any tmem_obj is accessed,
- * the hashbucket lock must be held.
- */
-
-static struct tmem_obj
-*__tmem_obj_find(struct tmem_hashbucket*hb, struct tmem_oid *oidp,
- struct rb_node **parent, struct rb_node ***link)
-{
- struct rb_node *_parent = NULL, **rbnode;
- struct tmem_obj *obj = NULL;
-
- rbnode = &hb->obj_rb_root.rb_node;
- while (*rbnode) {
- BUG_ON(RB_EMPTY_NODE(*rbnode));
- _parent = *rbnode;
- obj = rb_entry(*rbnode, struct tmem_obj,
- rb_tree_node);
- switch (tmem_oid_compare(oidp, &obj->oid)) {
- case 0: /* equal */
- goto out;
- case -1:
- rbnode = &(*rbnode)->rb_left;
- break;
- case 1:
- rbnode = &(*rbnode)->rb_right;
- break;
- }
- }
-
- if (parent)
- *parent = _parent;
- if (link)
- *link = rbnode;
-
- obj = NULL;
-out:
- return obj;
-}
-
-
-/* searches for object==oid in pool, returns locked object if found */
-static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
- struct tmem_oid *oidp)
-{
- return __tmem_obj_find(hb, oidp, NULL, NULL);
-}
-
-static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *);
-
-/* free an object that has no more pampds in it */
-static void tmem_obj_free(struct tmem_obj *obj, struct tmem_hashbucket *hb)
-{
- struct tmem_pool *pool;
-
- BUG_ON(obj == NULL);
- ASSERT_SENTINEL(obj, OBJ);
- BUG_ON(obj->pampd_count > 0);
- pool = obj->pool;
- BUG_ON(pool == NULL);
- if (obj->objnode_tree_root != NULL) /* may be "stump" with no leaves */
- tmem_pampd_destroy_all_in_obj(obj);
- BUG_ON(obj->objnode_tree_root != NULL);
- BUG_ON((long)obj->objnode_count != 0);
- atomic_dec(&pool->obj_count);
- BUG_ON(atomic_read(&pool->obj_count) < 0);
- INVERT_SENTINEL(obj, OBJ);
- obj->pool = NULL;
- tmem_oid_set_invalid(&obj->oid);
- rb_erase(&obj->rb_tree_node, &hb->obj_rb_root);
-}
-
-/*
- * initialize, and insert an tmem_object_root (called only if find failed)
- */
-static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
- struct tmem_pool *pool,
- struct tmem_oid *oidp)
-{
- struct rb_root *root = &hb->obj_rb_root;
- struct rb_node **new = NULL, *parent = NULL;
-
- BUG_ON(pool == NULL);
- atomic_inc(&pool->obj_count);
- obj->objnode_tree_height = 0;
- obj->objnode_tree_root = NULL;
- obj->pool = pool;
- obj->oid = *oidp;
- obj->objnode_count = 0;
- obj->pampd_count = 0;
- (*tmem_pamops.new_obj)(obj);
- SET_SENTINEL(obj, OBJ);
-
- if (__tmem_obj_find(hb, oidp, &parent, &new))
- BUG();
-
- rb_link_node(&obj->rb_tree_node, parent, new);
- rb_insert_color(&obj->rb_tree_node, root);
-}
-
-/*
- * Tmem is managed as a set of tmem_pools with certain attributes, such as
- * "ephemeral" vs "persistent". These attributes apply to all tmem_objs
- * and all pampds that belong to a tmem_pool. A tmem_pool is created
- * or deleted relatively rarely (for example, when a filesystem is
- * mounted or unmounted.
- */
-
-/* flush all data from a pool and, optionally, free it */
-static void tmem_pool_flush(struct tmem_pool *pool, bool destroy)
-{
- struct rb_node *rbnode;
- struct tmem_obj *obj;
- struct tmem_hashbucket *hb = &pool->hashbucket[0];
- int i;
-
- BUG_ON(pool == NULL);
- for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) {
- spin_lock(&hb->lock);
- rbnode = rb_first(&hb->obj_rb_root);
- while (rbnode != NULL) {
- obj = rb_entry(rbnode, struct tmem_obj, rb_tree_node);
- rbnode = rb_next(rbnode);
- tmem_pampd_destroy_all_in_obj(obj);
- tmem_obj_free(obj, hb);
- (*tmem_hostops.obj_free)(obj, pool);
- }
- spin_unlock(&hb->lock);
- }
- if (destroy)
- list_del(&pool->pool_list);
-}
-
-/*
- * A tmem_obj contains a radix-tree-like tree in which the intermediate
- * nodes are called tmem_objnodes. (The kernel lib/radix-tree.c implementation
- * is very specialized and tuned for specific uses and is not particularly
- * suited for use from this code, though some code from the core algorithms has
- * been reused, thus the copyright notices below). Each tmem_objnode contains
- * a set of pointers which point to either a set of intermediate tmem_objnodes
- * or a set of of pampds.
- *
- * Portions Copyright (C) 2001 Momchil Velikov
- * Portions Copyright (C) 2001 Christoph Hellwig
- * Portions Copyright (C) 2005 SGI, Christoph Lameter <clameter@sgi.com>
- */
-
-struct tmem_objnode_tree_path {
- struct tmem_objnode *objnode;
- int offset;
-};
-
-/* objnode height_to_maxindex translation */
-static unsigned long tmem_objnode_tree_h2max[OBJNODE_TREE_MAX_PATH + 1];
-
-static void tmem_objnode_tree_init(void)
-{
- unsigned int ht, tmp;
-
- for (ht = 0; ht < ARRAY_SIZE(tmem_objnode_tree_h2max); ht++) {
- tmp = ht * OBJNODE_TREE_MAP_SHIFT;
- if (tmp >= OBJNODE_TREE_INDEX_BITS)
- tmem_objnode_tree_h2max[ht] = ~0UL;
- else
- tmem_objnode_tree_h2max[ht] =
- (~0UL >> (OBJNODE_TREE_INDEX_BITS - tmp - 1)) >> 1;
- }
-}
-
-static struct tmem_objnode *tmem_objnode_alloc(struct tmem_obj *obj)
-{
- struct tmem_objnode *objnode;
-
- ASSERT_SENTINEL(obj, OBJ);
- BUG_ON(obj->pool == NULL);
- ASSERT_SENTINEL(obj->pool, POOL);
- objnode = (*tmem_hostops.objnode_alloc)(obj->pool);
- if (unlikely(objnode == NULL))
- goto out;
- objnode->obj = obj;
- SET_SENTINEL(objnode, OBJNODE);
- memset(&objnode->slots, 0, sizeof(objnode->slots));
- objnode->slots_in_use = 0;
- obj->objnode_count++;
-out:
- return objnode;
-}
-
-static void tmem_objnode_free(struct tmem_objnode *objnode)
-{
- struct tmem_pool *pool;
- int i;
-
- BUG_ON(objnode == NULL);
- for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++)
- BUG_ON(objnode->slots[i] != NULL);
- ASSERT_SENTINEL(objnode, OBJNODE);
- INVERT_SENTINEL(objnode, OBJNODE);
- BUG_ON(objnode->obj == NULL);
- ASSERT_SENTINEL(objnode->obj, OBJ);
- pool = objnode->obj->pool;
- BUG_ON(pool == NULL);
- ASSERT_SENTINEL(pool, POOL);
- objnode->obj->objnode_count--;
- objnode->obj = NULL;
- (*tmem_hostops.objnode_free)(objnode, pool);
-}
-
-/*
- * lookup index in object and return associated pampd (or NULL if not found)
- */
-static void **__tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
-{
- unsigned int height, shift;
- struct tmem_objnode **slot = NULL;
-
- BUG_ON(obj == NULL);
- ASSERT_SENTINEL(obj, OBJ);
- BUG_ON(obj->pool == NULL);
- ASSERT_SENTINEL(obj->pool, POOL);
-
- height = obj->objnode_tree_height;
- if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height])
- goto out;
- if (height == 0 && obj->objnode_tree_root) {
- slot = &obj->objnode_tree_root;
- goto out;
- }
- shift = (height-1) * OBJNODE_TREE_MAP_SHIFT;
- slot = &obj->objnode_tree_root;
- while (height > 0) {
- if (*slot == NULL)
- goto out;
- slot = (struct tmem_objnode **)
- ((*slot)->slots +
- ((index >> shift) & OBJNODE_TREE_MAP_MASK));
- shift -= OBJNODE_TREE_MAP_SHIFT;
- height--;
- }
-out:
- return slot != NULL ? (void **)slot : NULL;
-}
-
-static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
-{
- struct tmem_objnode **slot;
-
- slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
- return slot != NULL ? *slot : NULL;
-}
-
-static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index,
- void *new_pampd)
-{
- struct tmem_objnode **slot;
- void *ret = NULL;
-
- slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
- if ((slot != NULL) && (*slot != NULL)) {
- void *old_pampd = *(void **)slot;
- *(void **)slot = new_pampd;
- (*tmem_pamops.free)(old_pampd, obj->pool, NULL, 0);
- ret = new_pampd;
- }
- return ret;
-}
-
-static int tmem_pampd_add_to_obj(struct tmem_obj *obj, uint32_t index,
- void *pampd)
-{
- int ret = 0;
- struct tmem_objnode *objnode = NULL, *newnode, *slot;
- unsigned int height, shift;
- int offset = 0;
-
- /* if necessary, extend the tree to be higher */
- if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height]) {
- height = obj->objnode_tree_height + 1;
- if (index > tmem_objnode_tree_h2max[height])
- while (index > tmem_objnode_tree_h2max[height])
- height++;
- if (obj->objnode_tree_root == NULL) {
- obj->objnode_tree_height = height;
- goto insert;
- }
- do {
- newnode = tmem_objnode_alloc(obj);
- if (!newnode) {
- ret = -ENOMEM;
- goto out;
- }
- newnode->slots[0] = obj->objnode_tree_root;
- newnode->slots_in_use = 1;
- obj->objnode_tree_root = newnode;
- obj->objnode_tree_height++;
- } while (height > obj->objnode_tree_height);
- }
-insert:
- slot = obj->objnode_tree_root;
- height = obj->objnode_tree_height;
- shift = (height-1) * OBJNODE_TREE_MAP_SHIFT;
- while (height > 0) {
- if (slot == NULL) {
- /* add a child objnode. */
- slot = tmem_objnode_alloc(obj);
- if (!slot) {
- ret = -ENOMEM;
- goto out;
- }
- if (objnode) {
-
- objnode->slots[offset] = slot;
- objnode->slots_in_use++;
- } else
- obj->objnode_tree_root = slot;
- }
- /* go down a level */
- offset = (index >> shift) & OBJNODE_TREE_MAP_MASK;
- objnode = slot;
- slot = objnode->slots[offset];
- shift -= OBJNODE_TREE_MAP_SHIFT;
- height--;
- }
- BUG_ON(slot != NULL);
- if (objnode) {
- objnode->slots_in_use++;
- objnode->slots[offset] = pampd;
- } else
- obj->objnode_tree_root = pampd;
- obj->pampd_count++;
-out:
- return ret;
-}
-
-static void *tmem_pampd_delete_from_obj(struct tmem_obj *obj, uint32_t index)
-{
- struct tmem_objnode_tree_path path[OBJNODE_TREE_MAX_PATH + 1];
- struct tmem_objnode_tree_path *pathp = path;
- struct tmem_objnode *slot = NULL;
- unsigned int height, shift;
- int offset;
-
- BUG_ON(obj == NULL);
- ASSERT_SENTINEL(obj, OBJ);
- BUG_ON(obj->pool == NULL);
- ASSERT_SENTINEL(obj->pool, POOL);
- height = obj->objnode_tree_height;
- if (index > tmem_objnode_tree_h2max[height])
- goto out;
- slot = obj->objnode_tree_root;
- if (height == 0 && obj->objnode_tree_root) {
- obj->objnode_tree_root = NULL;
- goto out;
- }
- shift = (height - 1) * OBJNODE_TREE_MAP_SHIFT;
- pathp->objnode = NULL;
- do {
- if (slot == NULL)
- goto out;
- pathp++;
- offset = (index >> shift) & OBJNODE_TREE_MAP_MASK;
- pathp->offset = offset;
- pathp->objnode = slot;
- slot = slot->slots[offset];
- shift -= OBJNODE_TREE_MAP_SHIFT;
- height--;
- } while (height > 0);
- if (slot == NULL)
- goto out;
- while (pathp->objnode) {
- pathp->objnode->slots[pathp->offset] = NULL;
- pathp->objnode->slots_in_use--;
- if (pathp->objnode->slots_in_use) {
- if (pathp->objnode == obj->objnode_tree_root) {
- while (obj->objnode_tree_height > 0 &&
- obj->objnode_tree_root->slots_in_use == 1 &&
- obj->objnode_tree_root->slots[0]) {
- struct tmem_objnode *to_free =
- obj->objnode_tree_root;
-
- obj->objnode_tree_root =
- to_free->slots[0];
- obj->objnode_tree_height--;
- to_free->slots[0] = NULL;
- to_free->slots_in_use = 0;
- tmem_objnode_free(to_free);
- }
- }
- goto out;
- }
- tmem_objnode_free(pathp->objnode); /* 0 slots used, free it */
- pathp--;
- }
- obj->objnode_tree_height = 0;
- obj->objnode_tree_root = NULL;
-
-out:
- if (slot != NULL)
- obj->pampd_count--;
- BUG_ON(obj->pampd_count < 0);
- return slot;
-}
-
-/* recursively walk the objnode_tree destroying pampds and objnodes */
-static void tmem_objnode_node_destroy(struct tmem_obj *obj,
- struct tmem_objnode *objnode,
- unsigned int ht)
-{
- int i;
-
- if (ht == 0)
- return;
- for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++) {
- if (objnode->slots[i]) {
- if (ht == 1) {
- obj->pampd_count--;
- (*tmem_pamops.free)(objnode->slots[i],
- obj->pool, NULL, 0);
- objnode->slots[i] = NULL;
- continue;
- }
- tmem_objnode_node_destroy(obj, objnode->slots[i], ht-1);
- tmem_objnode_free(objnode->slots[i]);
- objnode->slots[i] = NULL;
- }
- }
-}
-
-static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
-{
- if (obj->objnode_tree_root == NULL)
- return;
- if (obj->objnode_tree_height == 0) {
- obj->pampd_count--;
- (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool, NULL, 0);
- } else {
- tmem_objnode_node_destroy(obj, obj->objnode_tree_root,
- obj->objnode_tree_height);
- tmem_objnode_free(obj->objnode_tree_root);
- obj->objnode_tree_height = 0;
- }
- obj->objnode_tree_root = NULL;
- (*tmem_pamops.free_obj)(obj->pool, obj);
-}
-
-/*
- * Tmem is operated on by a set of well-defined actions:
- * "put", "get", "flush", "flush_object", "new pool" and "destroy pool".
- * (The tmem ABI allows for subpages and exchanges but these operations
- * are not included in this implementation.)
- *
- * These "tmem core" operations are implemented in the following functions.
- */
-
-/*
- * "Put" a page, e.g. copy a page from the kernel into newly allocated
- * PAM space (if such space is available). Tmem_put is complicated by
- * a corner case: What if a page with matching handle already exists in
- * tmem? To guarantee coherency, one of two actions is necessary: Either
- * the data for the page must be overwritten, or the page must be
- * "flushed" so that the data is not accessible to a subsequent "get".
- * Since these "duplicate puts" are relatively rare, this implementation
- * always flushes for simplicity.
- */
-int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
- char *data, size_t size, bool raw, bool ephemeral)
-{
- struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL;
- void *pampd = NULL, *pampd_del = NULL;
- int ret = -ENOMEM;
- struct tmem_hashbucket *hb;
-
- hb = &pool->hashbucket[tmem_oid_hash(oidp)];
- spin_lock(&hb->lock);
- obj = objfound = tmem_obj_find(hb, oidp);
- if (obj != NULL) {
- pampd = tmem_pampd_lookup_in_obj(objfound, index);
- if (pampd != NULL) {
- /* if found, is a dup put, flush the old one */
- pampd_del = tmem_pampd_delete_from_obj(obj, index);
- BUG_ON(pampd_del != pampd);
- (*tmem_pamops.free)(pampd, pool, oidp, index);
- if (obj->pampd_count == 0) {
- objnew = obj;
- objfound = NULL;
- }
- pampd = NULL;
- }
- } else {
- obj = objnew = (*tmem_hostops.obj_alloc)(pool);
- if (unlikely(obj == NULL)) {
- ret = -ENOMEM;
- goto out;
- }
- tmem_obj_init(obj, hb, pool, oidp);
- }
- BUG_ON(obj == NULL);
- BUG_ON(((objnew != obj) && (objfound != obj)) || (objnew == objfound));
- pampd = (*tmem_pamops.create)(data, size, raw, ephemeral,
- obj->pool, &obj->oid, index);
- if (unlikely(pampd == NULL))
- goto free;
- ret = tmem_pampd_add_to_obj(obj, index, pampd);
- if (unlikely(ret == -ENOMEM))
- /* may have partially built objnode tree ("stump") */
- goto delete_and_free;
- goto out;
-
-delete_and_free:
- (void)tmem_pampd_delete_from_obj(obj, index);
-free:
- if (pampd)
- (*tmem_pamops.free)(pampd, pool, NULL, 0);
- if (objnew) {
- tmem_obj_free(objnew, hb);
- (*tmem_hostops.obj_free)(objnew, pool);
- }
-out:
- spin_unlock(&hb->lock);
- return ret;
-}
-
-/*
- * "Get" a page, e.g. if one can be found, copy the tmem page with the
- * matching handle from PAM space to the kernel. By tmem definition,
- * when a "get" is successful on an ephemeral page, the page is "flushed",
- * and when a "get" is successful on a persistent page, the page is retained
- * in tmem. Note that to preserve
- * coherency, "get" can never be skipped if tmem contains the data.
- * That is, if a get is done with a certain handle and fails, any
- * subsequent "get" must also fail (unless of course there is a
- * "put" done with the same handle).
-
- */
-int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
- char *data, size_t *size, bool raw, int get_and_free)
-{
- struct tmem_obj *obj;
- void *pampd;
- bool ephemeral = is_ephemeral(pool);
- int ret = -1;
- struct tmem_hashbucket *hb;
- bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral);
- bool lock_held = false;
-
- hb = &pool->hashbucket[tmem_oid_hash(oidp)];
- spin_lock(&hb->lock);
- lock_held = true;
- obj = tmem_obj_find(hb, oidp);
- if (obj == NULL)
- goto out;
- if (free)
- pampd = tmem_pampd_delete_from_obj(obj, index);
- else
- pampd = tmem_pampd_lookup_in_obj(obj, index);
- if (pampd == NULL)
- goto out;
- if (free) {
- if (obj->pampd_count == 0) {
- tmem_obj_free(obj, hb);
- (*tmem_hostops.obj_free)(obj, pool);
- obj = NULL;
- }
- }
- if (tmem_pamops.is_remote(pampd)) {
- lock_held = false;
- spin_unlock(&hb->lock);
- }
- if (free)
- ret = (*tmem_pamops.get_data_and_free)(
- data, size, raw, pampd, pool, oidp, index);
- else
- ret = (*tmem_pamops.get_data)(
- data, size, raw, pampd, pool, oidp, index);
- if (ret < 0)
- goto out;
- ret = 0;
-out:
- if (lock_held)
- spin_unlock(&hb->lock);
- return ret;
-}
-
-/*
- * If a page in tmem matches the handle, "flush" this page from tmem such
- * that any subsequent "get" does not succeed (unless, of course, there
- * was another "put" with the same handle).
- */
-int tmem_flush_page(struct tmem_pool *pool,
- struct tmem_oid *oidp, uint32_t index)
-{
- struct tmem_obj *obj;
- void *pampd;
- int ret = -1;
- struct tmem_hashbucket *hb;
-
- hb = &pool->hashbucket[tmem_oid_hash(oidp)];
- spin_lock(&hb->lock);
- obj = tmem_obj_find(hb, oidp);
- if (obj == NULL)
- goto out;
- pampd = tmem_pampd_delete_from_obj(obj, index);
- if (pampd == NULL)
- goto out;
- (*tmem_pamops.free)(pampd, pool, oidp, index);
- if (obj->pampd_count == 0) {
- tmem_obj_free(obj, hb);
- (*tmem_hostops.obj_free)(obj, pool);
- }
- ret = 0;
-
-out:
- spin_unlock(&hb->lock);
- return ret;
-}
-
-/*
- * If a page in tmem matches the handle, replace the page so that any
- * subsequent "get" gets the new page. Returns 0 if
- * there was a page to replace, else returns -1.
- */
-int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp,
- uint32_t index, void *new_pampd)
-{
- struct tmem_obj *obj;
- int ret = -1;
- struct tmem_hashbucket *hb;
-
- hb = &pool->hashbucket[tmem_oid_hash(oidp)];
- spin_lock(&hb->lock);
- obj = tmem_obj_find(hb, oidp);
- if (obj == NULL)
- goto out;
- new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd);
- ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj);
-out:
- spin_unlock(&hb->lock);
- return ret;
-}
-
-/*
- * "Flush" all pages in tmem matching this oid.
- */
-int tmem_flush_object(struct tmem_pool *pool, struct tmem_oid *oidp)
-{
- struct tmem_obj *obj;
- struct tmem_hashbucket *hb;
- int ret = -1;
-
- hb = &pool->hashbucket[tmem_oid_hash(oidp)];
- spin_lock(&hb->lock);
- obj = tmem_obj_find(hb, oidp);
- if (obj == NULL)
- goto out;
- tmem_pampd_destroy_all_in_obj(obj);
- tmem_obj_free(obj, hb);
- (*tmem_hostops.obj_free)(obj, pool);
- ret = 0;
-
-out:
- spin_unlock(&hb->lock);
- return ret;
-}
-
-/*
- * "Flush" all pages (and tmem_objs) from this tmem_pool and disable
- * all subsequent access to this tmem_pool.
- */
-int tmem_destroy_pool(struct tmem_pool *pool)
-{
- int ret = -1;
-
- if (pool == NULL)
- goto out;
- tmem_pool_flush(pool, 1);
- ret = 0;
-out:
- return ret;
-}
-
-static LIST_HEAD(tmem_global_pool_list);
-
-/*
- * Create a new tmem_pool with the provided flag and return
- * a pool id provided by the tmem host implementation.
- */
-void tmem_new_pool(struct tmem_pool *pool, uint32_t flags)
-{
- int persistent = flags & TMEM_POOL_PERSIST;
- int shared = flags & TMEM_POOL_SHARED;
- struct tmem_hashbucket *hb = &pool->hashbucket[0];
- int i;
-
- for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) {
- hb->obj_rb_root = RB_ROOT;
- spin_lock_init(&hb->lock);
- }
- INIT_LIST_HEAD(&pool->pool_list);
- atomic_set(&pool->obj_count, 0);
- SET_SENTINEL(pool, POOL);
- list_add_tail(&pool->pool_list, &tmem_global_pool_list);
- pool->persistent = persistent;
- pool->shared = shared;
-}
+++ /dev/null
-/*
- * zcache.c
- *
- * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp.
- * Copyright (c) 2010,2011, Nitin Gupta
- *
- * Zcache provides an in-kernel "host implementation" for transcendent memory
- * and, thus indirectly, for cleancache and frontswap. Zcache includes two
- * page-accessible memory [1] interfaces, both utilizing the crypto compression
- * API:
- * 1) "compression buddies" ("zbud") is used for ephemeral pages
- * 2) zsmalloc is used for persistent pages.
- * Xvmalloc (based on the TLSF allocator) has very low fragmentation
- * so maximizes space efficiency, while zbud allows pairs (and potentially,
- * in the future, more than a pair of) compressed pages to be closely linked
- * so that reclaiming can be done via the kernel's physical-page-oriented
- * "shrinker" interface.
- *
- * [1] For a definition of page-accessible memory (aka PAM), see:
- * http://marc.info/?l=linux-mm&m=127811271605009
- */
-
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/highmem.h>
-#include <linux/list.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/types.h>
-#include <linux/atomic.h>
-#include <linux/math64.h>
-#include <linux/crypto.h>
-#include <linux/string.h>
-#include <linux/idr.h>
-#include "tmem.h"
-
-#include "../zsmalloc/zsmalloc.h"
-
-#ifdef CONFIG_CLEANCACHE
-#include <linux/cleancache.h>
-#endif
-#ifdef CONFIG_FRONTSWAP
-#include <linux/frontswap.h>
-#endif
-
-#if 0
-/* this is more aggressive but may cause other problems? */
-#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN)
-#else
-#define ZCACHE_GFP_MASK \
- (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC)
-#endif
-
-#define MAX_CLIENTS 16
-#define LOCAL_CLIENT ((uint16_t)-1)
-
-MODULE_LICENSE("GPL");
-
-struct zcache_client {
- struct idr tmem_pools;
- struct zs_pool *zspool;
- bool allocated;
- atomic_t refcount;
-};
-
-static struct zcache_client zcache_host;
-static struct zcache_client zcache_clients[MAX_CLIENTS];
-
-static inline uint16_t get_client_id_from_client(struct zcache_client *cli)
-{
- BUG_ON(cli == NULL);
- if (cli == &zcache_host)
- return LOCAL_CLIENT;
- return cli - &zcache_clients[0];
-}
-
-static struct zcache_client *get_zcache_client(uint16_t cli_id)
-{
- if (cli_id == LOCAL_CLIENT)
- return &zcache_host;
-
- if ((unsigned int)cli_id < MAX_CLIENTS)
- return &zcache_clients[cli_id];
-
- return NULL;
-}
-
-static inline bool is_local_client(struct zcache_client *cli)
-{
- return cli == &zcache_host;
-}
-
-/* crypto API for zcache */
-#define ZCACHE_COMP_NAME_SZ CRYPTO_MAX_ALG_NAME
-static char zcache_comp_name[ZCACHE_COMP_NAME_SZ];
-static struct crypto_comp * __percpu *zcache_comp_pcpu_tfms;
-
-enum comp_op {
- ZCACHE_COMPOP_COMPRESS,
- ZCACHE_COMPOP_DECOMPRESS
-};
-
-static inline int zcache_comp_op(enum comp_op op,
- const u8 *src, unsigned int slen,
- u8 *dst, unsigned int *dlen)
-{
- struct crypto_comp *tfm;
- int ret;
-
- BUG_ON(!zcache_comp_pcpu_tfms);
- tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, get_cpu());
- BUG_ON(!tfm);
- switch (op) {
- case ZCACHE_COMPOP_COMPRESS:
- ret = crypto_comp_compress(tfm, src, slen, dst, dlen);
- break;
- case ZCACHE_COMPOP_DECOMPRESS:
- ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
- break;
- default:
- ret = -EINVAL;
- }
- put_cpu();
- return ret;
-}
-
-/**********
- * Compression buddies ("zbud") provides for packing two (or, possibly
- * in the future, more) compressed ephemeral pages into a single "raw"
- * (physical) page and tracking them with data structures so that
- * the raw pages can be easily reclaimed.
- *
- * A zbud page ("zbpg") is an aligned page containing a list_head,
- * a lock, and two "zbud headers". The remainder of the physical
- * page is divided up into aligned 64-byte "chunks" which contain
- * the compressed data for zero, one, or two zbuds. Each zbpg
- * resides on: (1) an "unused list" if it has no zbuds; (2) a
- * "buddied" list if it is fully populated with two zbuds; or
- * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks
- * the one unbuddied zbud uses. The data inside a zbpg cannot be
- * read or written unless the zbpg's lock is held.
- */
-
-#define ZBH_SENTINEL 0x43214321
-#define ZBPG_SENTINEL 0xdeadbeef
-
-#define ZBUD_MAX_BUDS 2
-
-struct zbud_hdr {
- uint16_t client_id;
- uint16_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- uint16_t size; /* compressed size in bytes, zero means unused */
- DECL_SENTINEL
-};
-
-struct zbud_page {
- struct list_head bud_list;
- spinlock_t lock;
- struct zbud_hdr buddy[ZBUD_MAX_BUDS];
- DECL_SENTINEL
- /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */
-};
-
-#define CHUNK_SHIFT 6
-#define CHUNK_SIZE (1 << CHUNK_SHIFT)
-#define CHUNK_MASK (~(CHUNK_SIZE-1))
-#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \
- CHUNK_MASK) >> CHUNK_SHIFT)
-#define MAX_CHUNK (NCHUNKS-1)
-
-static struct {
- struct list_head list;
- unsigned count;
-} zbud_unbuddied[NCHUNKS];
-/* list N contains pages with N chunks USED and NCHUNKS-N unused */
-/* element 0 is never used but optimizing that isn't worth it */
-static unsigned long zbud_cumul_chunk_counts[NCHUNKS];
-
-struct list_head zbud_buddied_list;
-static unsigned long zcache_zbud_buddied_count;
-
-/* protects the buddied list and all unbuddied lists */
-static DEFINE_SPINLOCK(zbud_budlists_spinlock);
-
-static LIST_HEAD(zbpg_unused_list);
-static unsigned long zcache_zbpg_unused_list_count;
-
-/* protects the unused page list */
-static DEFINE_SPINLOCK(zbpg_unused_list_spinlock);
-
-static atomic_t zcache_zbud_curr_raw_pages;
-static atomic_t zcache_zbud_curr_zpages;
-static unsigned long zcache_zbud_curr_zbytes;
-static unsigned long zcache_zbud_cumul_zpages;
-static unsigned long zcache_zbud_cumul_zbytes;
-static unsigned long zcache_compress_poor;
-static unsigned long zcache_mean_compress_poor;
-
-/* forward references */
-static void *zcache_get_free_page(void);
-static void zcache_free_page(void *p);
-
-/*
- * zbud helper functions
- */
-
-static inline unsigned zbud_max_buddy_size(void)
-{
- return MAX_CHUNK << CHUNK_SHIFT;
-}
-
-static inline unsigned zbud_size_to_chunks(unsigned size)
-{
- BUG_ON(size == 0 || size > zbud_max_buddy_size());
- return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
-}
-
-static inline int zbud_budnum(struct zbud_hdr *zh)
-{
- unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1);
- struct zbud_page *zbpg = NULL;
- unsigned budnum = -1U;
- int i;
-
- for (i = 0; i < ZBUD_MAX_BUDS; i++)
- if (offset == offsetof(typeof(*zbpg), buddy[i])) {
- budnum = i;
- break;
- }
- BUG_ON(budnum == -1U);
- return budnum;
-}
-
-static char *zbud_data(struct zbud_hdr *zh, unsigned size)
-{
- struct zbud_page *zbpg;
- char *p;
- unsigned budnum;
-
- ASSERT_SENTINEL(zh, ZBH);
- budnum = zbud_budnum(zh);
- BUG_ON(size == 0 || size > zbud_max_buddy_size());
- zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
- ASSERT_SPINLOCK(&zbpg->lock);
- p = (char *)zbpg;
- if (budnum == 0)
- p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) &
- CHUNK_MASK);
- else if (budnum == 1)
- p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK);
- return p;
-}
-
-/*
- * zbud raw page management
- */
-
-static struct zbud_page *zbud_alloc_raw_page(void)
-{
- struct zbud_page *zbpg = NULL;
- struct zbud_hdr *zh0, *zh1;
- bool recycled = 0;
-
- /* if any pages on the zbpg list, use one */
- spin_lock(&zbpg_unused_list_spinlock);
- if (!list_empty(&zbpg_unused_list)) {
- zbpg = list_first_entry(&zbpg_unused_list,
- struct zbud_page, bud_list);
- list_del_init(&zbpg->bud_list);
- zcache_zbpg_unused_list_count--;
- recycled = 1;
- }
- spin_unlock(&zbpg_unused_list_spinlock);
- if (zbpg == NULL)
- /* none on zbpg list, try to get a kernel page */
- zbpg = zcache_get_free_page();
- if (likely(zbpg != NULL)) {
- INIT_LIST_HEAD(&zbpg->bud_list);
- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1];
- spin_lock_init(&zbpg->lock);
- if (recycled) {
- ASSERT_INVERTED_SENTINEL(zbpg, ZBPG);
- SET_SENTINEL(zbpg, ZBPG);
- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid));
- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid));
- } else {
- atomic_inc(&zcache_zbud_curr_raw_pages);
- INIT_LIST_HEAD(&zbpg->bud_list);
- SET_SENTINEL(zbpg, ZBPG);
- zh0->size = 0; zh1->size = 0;
- tmem_oid_set_invalid(&zh0->oid);
- tmem_oid_set_invalid(&zh1->oid);
- }
- }
- return zbpg;
-}
-
-static void zbud_free_raw_page(struct zbud_page *zbpg)
-{
- struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1];
-
- ASSERT_SENTINEL(zbpg, ZBPG);
- BUG_ON(!list_empty(&zbpg->bud_list));
- ASSERT_SPINLOCK(&zbpg->lock);
- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid));
- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid));
- INVERT_SENTINEL(zbpg, ZBPG);
- spin_unlock(&zbpg->lock);
- spin_lock(&zbpg_unused_list_spinlock);
- list_add(&zbpg->bud_list, &zbpg_unused_list);
- zcache_zbpg_unused_list_count++;
- spin_unlock(&zbpg_unused_list_spinlock);
-}
-
-/*
- * core zbud handling routines
- */
-
-static unsigned zbud_free(struct zbud_hdr *zh)
-{
- unsigned size;
-
- ASSERT_SENTINEL(zh, ZBH);
- BUG_ON(!tmem_oid_valid(&zh->oid));
- size = zh->size;
- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size());
- zh->size = 0;
- tmem_oid_set_invalid(&zh->oid);
- INVERT_SENTINEL(zh, ZBH);
- zcache_zbud_curr_zbytes -= size;
- atomic_dec(&zcache_zbud_curr_zpages);
- return size;
-}
-
-static void zbud_free_and_delist(struct zbud_hdr *zh)
-{
- unsigned chunks;
- struct zbud_hdr *zh_other;
- unsigned budnum = zbud_budnum(zh), size;
- struct zbud_page *zbpg =
- container_of(zh, struct zbud_page, buddy[budnum]);
-
- spin_lock(&zbud_budlists_spinlock);
- spin_lock(&zbpg->lock);
- if (list_empty(&zbpg->bud_list)) {
- /* ignore zombie page... see zbud_evict_pages() */
- spin_unlock(&zbpg->lock);
- spin_unlock(&zbud_budlists_spinlock);
- return;
- }
- size = zbud_free(zh);
- ASSERT_SPINLOCK(&zbpg->lock);
- zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0];
- if (zh_other->size == 0) { /* was unbuddied: unlist and free */
- chunks = zbud_size_to_chunks(size) ;
- BUG_ON(list_empty(&zbud_unbuddied[chunks].list));
- list_del_init(&zbpg->bud_list);
- zbud_unbuddied[chunks].count--;
- spin_unlock(&zbud_budlists_spinlock);
- zbud_free_raw_page(zbpg);
- } else { /* was buddied: move remaining buddy to unbuddied list */
- chunks = zbud_size_to_chunks(zh_other->size) ;
- list_del_init(&zbpg->bud_list);
- zcache_zbud_buddied_count--;
- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list);
- zbud_unbuddied[chunks].count++;
- spin_unlock(&zbud_budlists_spinlock);
- spin_unlock(&zbpg->lock);
- }
-}
-
-static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id,
- struct tmem_oid *oid,
- uint32_t index, struct page *page,
- void *cdata, unsigned size)
-{
- struct zbud_hdr *zh0, *zh1, *zh = NULL;
- struct zbud_page *zbpg = NULL, *ztmp;
- unsigned nchunks;
- char *to;
- int i, found_good_buddy = 0;
-
- nchunks = zbud_size_to_chunks(size) ;
- for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) {
- spin_lock(&zbud_budlists_spinlock);
- if (!list_empty(&zbud_unbuddied[i].list)) {
- list_for_each_entry_safe(zbpg, ztmp,
- &zbud_unbuddied[i].list, bud_list) {
- if (spin_trylock(&zbpg->lock)) {
- found_good_buddy = i;
- goto found_unbuddied;
- }
- }
- }
- spin_unlock(&zbud_budlists_spinlock);
- }
- /* didn't find a good buddy, try allocating a new page */
- zbpg = zbud_alloc_raw_page();
- if (unlikely(zbpg == NULL))
- goto out;
- /* ok, have a page, now compress the data before taking locks */
- spin_lock(&zbud_budlists_spinlock);
- spin_lock(&zbpg->lock);
- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list);
- zbud_unbuddied[nchunks].count++;
- zh = &zbpg->buddy[0];
- goto init_zh;
-
-found_unbuddied:
- ASSERT_SPINLOCK(&zbpg->lock);
- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1];
- BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0)));
- if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */
- ASSERT_SENTINEL(zh0, ZBH);
- zh = zh1;
- } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */
- ASSERT_SENTINEL(zh1, ZBH);
- zh = zh0;
- } else
- BUG();
- list_del_init(&zbpg->bud_list);
- zbud_unbuddied[found_good_buddy].count--;
- list_add_tail(&zbpg->bud_list, &zbud_buddied_list);
- zcache_zbud_buddied_count++;
-
-init_zh:
- SET_SENTINEL(zh, ZBH);
- zh->size = size;
- zh->index = index;
- zh->oid = *oid;
- zh->pool_id = pool_id;
- zh->client_id = client_id;
- to = zbud_data(zh, size);
- memcpy(to, cdata, size);
- spin_unlock(&zbpg->lock);
- spin_unlock(&zbud_budlists_spinlock);
-
- zbud_cumul_chunk_counts[nchunks]++;
- atomic_inc(&zcache_zbud_curr_zpages);
- zcache_zbud_cumul_zpages++;
- zcache_zbud_curr_zbytes += size;
- zcache_zbud_cumul_zbytes += size;
-out:
- return zh;
-}
-
-static int zbud_decompress(struct page *page, struct zbud_hdr *zh)
-{
- struct zbud_page *zbpg;
- unsigned budnum = zbud_budnum(zh);
- unsigned int out_len = PAGE_SIZE;
- char *to_va, *from_va;
- unsigned size;
- int ret = 0;
-
- zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
- spin_lock(&zbpg->lock);
- if (list_empty(&zbpg->bud_list)) {
- /* ignore zombie page... see zbud_evict_pages() */
- ret = -EINVAL;
- goto out;
- }
- ASSERT_SENTINEL(zh, ZBH);
- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size());
- to_va = kmap_atomic(page);
- size = zh->size;
- from_va = zbud_data(zh, size);
- ret = zcache_comp_op(ZCACHE_COMPOP_DECOMPRESS, from_va, size,
- to_va, &out_len);
- BUG_ON(ret);
- BUG_ON(out_len != PAGE_SIZE);
- kunmap_atomic(to_va);
-out:
- spin_unlock(&zbpg->lock);
- return ret;
-}
-
-/*
- * The following routines handle shrinking of ephemeral pages by evicting
- * pages "least valuable" first.
- */
-
-static unsigned long zcache_evicted_raw_pages;
-static unsigned long zcache_evicted_buddied_pages;
-static unsigned long zcache_evicted_unbuddied_pages;
-
-static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id,
- uint16_t poolid);
-static void zcache_put_pool(struct tmem_pool *pool);
-
-/*
- * Flush and free all zbuds in a zbpg, then free the pageframe
- */
-static void zbud_evict_zbpg(struct zbud_page *zbpg)
-{
- struct zbud_hdr *zh;
- int i, j;
- uint32_t pool_id[ZBUD_MAX_BUDS], client_id[ZBUD_MAX_BUDS];
- uint32_t index[ZBUD_MAX_BUDS];
- struct tmem_oid oid[ZBUD_MAX_BUDS];
- struct tmem_pool *pool;
-
- ASSERT_SPINLOCK(&zbpg->lock);
- BUG_ON(!list_empty(&zbpg->bud_list));
- for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) {
- zh = &zbpg->buddy[i];
- if (zh->size) {
- client_id[j] = zh->client_id;
- pool_id[j] = zh->pool_id;
- oid[j] = zh->oid;
- index[j] = zh->index;
- j++;
- zbud_free(zh);
- }
- }
- spin_unlock(&zbpg->lock);
- for (i = 0; i < j; i++) {
- pool = zcache_get_pool_by_id(client_id[i], pool_id[i]);
- if (pool != NULL) {
- tmem_flush_page(pool, &oid[i], index[i]);
- zcache_put_pool(pool);
- }
- }
- ASSERT_SENTINEL(zbpg, ZBPG);
- spin_lock(&zbpg->lock);
- zbud_free_raw_page(zbpg);
-}
-
-/*
- * Free nr pages. This code is funky because we want to hold the locks
- * protecting various lists for as short a time as possible, and in some
- * circumstances the list may change asynchronously when the list lock is
- * not held. In some cases we also trylock not only to avoid waiting on a
- * page in use by another cpu, but also to avoid potential deadlock due to
- * lock inversion.
- */
-static void zbud_evict_pages(int nr)
-{
- struct zbud_page *zbpg;
- int i;
-
- /* first try freeing any pages on unused list */
-retry_unused_list:
- spin_lock_bh(&zbpg_unused_list_spinlock);
- if (!list_empty(&zbpg_unused_list)) {
- /* can't walk list here, since it may change when unlocked */
- zbpg = list_first_entry(&zbpg_unused_list,
- struct zbud_page, bud_list);
- list_del_init(&zbpg->bud_list);
- zcache_zbpg_unused_list_count--;
- atomic_dec(&zcache_zbud_curr_raw_pages);
- spin_unlock_bh(&zbpg_unused_list_spinlock);
- zcache_free_page(zbpg);
- zcache_evicted_raw_pages++;
- if (--nr <= 0)
- goto out;
- goto retry_unused_list;
- }
- spin_unlock_bh(&zbpg_unused_list_spinlock);
-
- /* now try freeing unbuddied pages, starting with least space avail */
- for (i = 0; i < MAX_CHUNK; i++) {
-retry_unbud_list_i:
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_unbuddied[i].list)) {
- spin_unlock_bh(&zbud_budlists_spinlock);
- continue;
- }
- list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue;
- list_del_init(&zbpg->bud_list);
- zbud_unbuddied[i].count--;
- spin_unlock(&zbud_budlists_spinlock);
- zcache_evicted_unbuddied_pages++;
- /* want budlists unlocked when doing zbpg eviction */
- zbud_evict_zbpg(zbpg);
- local_bh_enable();
- if (--nr <= 0)
- goto out;
- goto retry_unbud_list_i;
- }
- spin_unlock_bh(&zbud_budlists_spinlock);
- }
-
- /* as a last resort, free buddied pages */
-retry_bud_list:
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_buddied_list)) {
- spin_unlock_bh(&zbud_budlists_spinlock);
- goto out;
- }
- list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue;
- list_del_init(&zbpg->bud_list);
- zcache_zbud_buddied_count--;
- spin_unlock(&zbud_budlists_spinlock);
- zcache_evicted_buddied_pages++;
- /* want budlists unlocked when doing zbpg eviction */
- zbud_evict_zbpg(zbpg);
- local_bh_enable();
- if (--nr <= 0)
- goto out;
- goto retry_bud_list;
- }
- spin_unlock_bh(&zbud_budlists_spinlock);
-out:
- return;
-}
-
-static void __init zbud_init(void)
-{
- int i;
-
- INIT_LIST_HEAD(&zbud_buddied_list);
-
- for (i = 0; i < NCHUNKS; i++)
- INIT_LIST_HEAD(&zbud_unbuddied[i].list);
-}
-
-#ifdef CONFIG_SYSFS
-/*
- * These sysfs routines show a nice distribution of how many zbpg's are
- * currently (and have ever been placed) in each unbuddied list. It's fun
- * to watch but can probably go away before final merge.
- */
-static int zbud_show_unbuddied_list_counts(char *buf)
-{
- int i;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++)
- p += sprintf(p, "%u ", zbud_unbuddied[i].count);
- return p - buf;
-}
-
-static int zbud_show_cumul_chunk_counts(char *buf)
-{
- unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0;
- unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0;
- unsigned long total_chunks_lte_42 = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]);
- chunks += zbud_cumul_chunk_counts[i];
- total_chunks += zbud_cumul_chunk_counts[i];
- sum_total_chunks += i * zbud_cumul_chunk_counts[i];
- if (i == 21)
- total_chunks_lte_21 = total_chunks;
- if (i == 32)
- total_chunks_lte_32 = total_chunks;
- if (i == 42)
- total_chunks_lte_42 = total_chunks;
- }
- p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n",
- total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42,
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-#endif
-
-/**********
- * This "zv" PAM implementation combines the slab-based zsmalloc
- * with the crypto compression API to maximize the amount of data that can
- * be packed into a physical page.
- *
- * Zv represents a PAM page with the index and object (plus a "size" value
- * necessary for decompression) immediately preceding the compressed data.
- */
-
-#define ZVH_SENTINEL 0x43214321
-
-struct zv_hdr {
- uint32_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- size_t size;
- DECL_SENTINEL
-};
-
-/* rudimentary policy limits */
-/* total number of persistent pages may not exceed this percentage */
-static unsigned int zv_page_count_policy_percent = 75;
-/*
- * byte count defining poor compression; pages with greater zsize will be
- * rejected
- */
-static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7;
-/*
- * byte count defining poor *mean* compression; pages with greater zsize
- * will be rejected until sufficient better-compressed pages are accepted
- * driving the mean below this threshold
- */
-static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5;
-
-static atomic_t zv_curr_dist_counts[NCHUNKS];
-static atomic_t zv_cumul_dist_counts[NCHUNKS];
-
-static unsigned long zv_create(struct zs_pool *pool, uint32_t pool_id,
- struct tmem_oid *oid, uint32_t index,
- void *cdata, unsigned clen)
-{
- struct zv_hdr *zv;
- u32 size = clen + sizeof(struct zv_hdr);
- int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
- unsigned long handle = 0;
-
- BUG_ON(!irqs_disabled());
- BUG_ON(chunks >= NCHUNKS);
- handle = zs_malloc(pool, size);
- if (!handle)
- goto out;
- atomic_inc(&zv_curr_dist_counts[chunks]);
- atomic_inc(&zv_cumul_dist_counts[chunks]);
- zv = zs_map_object(pool, handle, ZS_MM_WO);
- zv->index = index;
- zv->oid = *oid;
- zv->pool_id = pool_id;
- zv->size = clen;
- SET_SENTINEL(zv, ZVH);
- memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen);
- zs_unmap_object(pool, handle);
-out:
- return handle;
-}
-
-static void zv_free(struct zs_pool *pool, unsigned long handle)
-{
- unsigned long flags;
- struct zv_hdr *zv;
- uint16_t size;
- int chunks;
-
- zv = zs_map_object(pool, handle, ZS_MM_RW);
- ASSERT_SENTINEL(zv, ZVH);
- size = zv->size + sizeof(struct zv_hdr);
- INVERT_SENTINEL(zv, ZVH);
- zs_unmap_object(pool, handle);
-
- chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
- BUG_ON(chunks >= NCHUNKS);
- atomic_dec(&zv_curr_dist_counts[chunks]);
-
- local_irq_save(flags);
- zs_free(pool, handle);
- local_irq_restore(flags);
-}
-
-static void zv_decompress(struct page *page, unsigned long handle)
-{
- unsigned int clen = PAGE_SIZE;
- char *to_va;
- int ret;
- struct zv_hdr *zv;
-
- zv = zs_map_object(zcache_host.zspool, handle, ZS_MM_RO);
- BUG_ON(zv->size == 0);
- ASSERT_SENTINEL(zv, ZVH);
- to_va = kmap_atomic(page);
- ret = zcache_comp_op(ZCACHE_COMPOP_DECOMPRESS, (char *)zv + sizeof(*zv),
- zv->size, to_va, &clen);
- kunmap_atomic(to_va);
- zs_unmap_object(zcache_host.zspool, handle);
- BUG_ON(ret);
- BUG_ON(clen != PAGE_SIZE);
-}
-
-#ifdef CONFIG_SYSFS
-/*
- * show a distribution of compression stats for zv pages.
- */
-
-static int zv_curr_dist_counts_show(char *buf)
-{
- unsigned long i, n, chunks = 0, sum_total_chunks = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- n = atomic_read(&zv_curr_dist_counts[i]);
- p += sprintf(p, "%lu ", n);
- chunks += n;
- sum_total_chunks += i * n;
- }
- p += sprintf(p, "mean:%lu\n",
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-
-static int zv_cumul_dist_counts_show(char *buf)
-{
- unsigned long i, n, chunks = 0, sum_total_chunks = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- n = atomic_read(&zv_cumul_dist_counts[i]);
- p += sprintf(p, "%lu ", n);
- chunks += n;
- sum_total_chunks += i * n;
- }
- p += sprintf(p, "mean:%lu\n",
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-
-/*
- * setting zv_max_zsize via sysfs causes all persistent (e.g. swap)
- * pages that don't compress to less than this value (including metadata
- * overhead) to be rejected. We don't allow the value to get too close
- * to PAGE_SIZE.
- */
-static ssize_t zv_max_zsize_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_max_zsize);
-}
-
-static ssize_t zv_max_zsize_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7))
- return -EINVAL;
- zv_max_zsize = val;
- return count;
-}
-
-/*
- * setting zv_max_mean_zsize via sysfs causes all persistent (e.g. swap)
- * pages that don't compress to less than this value (including metadata
- * overhead) to be rejected UNLESS the mean compression is also smaller
- * than this value. In other words, we are load-balancing-by-zsize the
- * accepted pages. Again, we don't allow the value to get too close
- * to PAGE_SIZE.
- */
-static ssize_t zv_max_mean_zsize_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_max_mean_zsize);
-}
-
-static ssize_t zv_max_mean_zsize_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7))
- return -EINVAL;
- zv_max_mean_zsize = val;
- return count;
-}
-
-/*
- * setting zv_page_count_policy_percent via sysfs sets an upper bound of
- * persistent (e.g. swap) pages that will be retained according to:
- * (zv_page_count_policy_percent * totalram_pages) / 100)
- * when that limit is reached, further puts will be rejected (until
- * some pages have been flushed). Note that, due to compression,
- * this number may exceed 100; it defaults to 75 and we set an
- * arbitary limit of 150. A poor choice will almost certainly result
- * in OOM's, so this value should only be changed prudently.
- */
-static ssize_t zv_page_count_policy_percent_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_page_count_policy_percent);
-}
-
-static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > 150))
- return -EINVAL;
- zv_page_count_policy_percent = val;
- return count;
-}
-
-static struct kobj_attribute zcache_zv_max_zsize_attr = {
- .attr = { .name = "zv_max_zsize", .mode = 0644 },
- .show = zv_max_zsize_show,
- .store = zv_max_zsize_store,
-};
-
-static struct kobj_attribute zcache_zv_max_mean_zsize_attr = {
- .attr = { .name = "zv_max_mean_zsize", .mode = 0644 },
- .show = zv_max_mean_zsize_show,
- .store = zv_max_mean_zsize_store,
-};
-
-static struct kobj_attribute zcache_zv_page_count_policy_percent_attr = {
- .attr = { .name = "zv_page_count_policy_percent",
- .mode = 0644 },
- .show = zv_page_count_policy_percent_show,
- .store = zv_page_count_policy_percent_store,
-};
-#endif
-
-/*
- * zcache core code starts here
- */
-
-/* useful stats not collected by cleancache or frontswap */
-static unsigned long zcache_flush_total;
-static unsigned long zcache_flush_found;
-static unsigned long zcache_flobj_total;
-static unsigned long zcache_flobj_found;
-static unsigned long zcache_failed_eph_puts;
-static unsigned long zcache_failed_pers_puts;
-
-/*
- * Tmem operations assume the poolid implies the invoking client.
- * Zcache only has one client (the kernel itself): LOCAL_CLIENT.
- * RAMster has each client numbered by cluster node, and a KVM version
- * of zcache would have one client per guest and each client might
- * have a poolid==N.
- */
-static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
-{
- struct tmem_pool *pool = NULL;
- struct zcache_client *cli = NULL;
-
- cli = get_zcache_client(cli_id);
- if (!cli)
- goto out;
-
- atomic_inc(&cli->refcount);
- pool = idr_find(&cli->tmem_pools, poolid);
- if (pool != NULL)
- atomic_inc(&pool->refcount);
-out:
- return pool;
-}
-
-static void zcache_put_pool(struct tmem_pool *pool)
-{
- struct zcache_client *cli = NULL;
-
- if (pool == NULL)
- BUG();
- cli = pool->client;
- atomic_dec(&pool->refcount);
- atomic_dec(&cli->refcount);
-}
-
-int zcache_new_client(uint16_t cli_id)
-{
- struct zcache_client *cli;
- int ret = -1;
-
- cli = get_zcache_client(cli_id);
-
- if (cli == NULL)
- goto out;
- if (cli->allocated)
- goto out;
- cli->allocated = 1;
-#ifdef CONFIG_FRONTSWAP
- cli->zspool = zs_create_pool("zcache", ZCACHE_GFP_MASK);
- if (cli->zspool == NULL)
- goto out;
- idr_init(&cli->tmem_pools);
-#endif
- ret = 0;
-out:
- return ret;
-}
-
-/* counters for debugging */
-static unsigned long zcache_failed_get_free_pages;
-static unsigned long zcache_failed_alloc;
-static unsigned long zcache_put_to_flush;
-
-/*
- * for now, used named slabs so can easily track usage; later can
- * either just use kmalloc, or perhaps add a slab-like allocator
- * to more carefully manage total memory utilization
- */
-static struct kmem_cache *zcache_objnode_cache;
-static struct kmem_cache *zcache_obj_cache;
-static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_obj_count_max;
-static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_objnode_count_max;
-
-/*
- * to avoid memory allocation recursion (e.g. due to direct reclaim), we
- * preload all necessary data structures so the hostops callbacks never
- * actually do a malloc
- */
-struct zcache_preload {
- void *page;
- struct tmem_obj *obj;
- int nr;
- struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH];
-};
-static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, };
-
-static int zcache_do_preload(struct tmem_pool *pool)
-{
- struct zcache_preload *kp;
- struct tmem_objnode *objnode;
- struct tmem_obj *obj;
- void *page;
- int ret = -ENOMEM;
-
- if (unlikely(zcache_objnode_cache == NULL))
- goto out;
- if (unlikely(zcache_obj_cache == NULL))
- goto out;
-
- /* IRQ has already been disabled. */
- kp = &__get_cpu_var(zcache_preloads);
- while (kp->nr < ARRAY_SIZE(kp->objnodes)) {
- objnode = kmem_cache_alloc(zcache_objnode_cache,
- ZCACHE_GFP_MASK);
- if (unlikely(objnode == NULL)) {
- zcache_failed_alloc++;
- goto out;
- }
-
- kp->objnodes[kp->nr++] = objnode;
- }
-
- if (!kp->obj) {
- obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
- if (unlikely(obj == NULL)) {
- zcache_failed_alloc++;
- goto out;
- }
- kp->obj = obj;
- }
-
- if (!kp->page) {
- page = (void *)__get_free_page(ZCACHE_GFP_MASK);
- if (unlikely(page == NULL)) {
- zcache_failed_get_free_pages++;
- goto out;
- }
- kp->page = page;
- }
-
- ret = 0;
-out:
- return ret;
-}
-
-static void *zcache_get_free_page(void)
-{
- struct zcache_preload *kp;
- void *page;
-
- kp = &__get_cpu_var(zcache_preloads);
- page = kp->page;
- BUG_ON(page == NULL);
- kp->page = NULL;
- return page;
-}
-
-static void zcache_free_page(void *p)
-{
- free_page((unsigned long)p);
-}
-
-/*
- * zcache implementation for tmem host ops
- */
-
-static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool)
-{
- struct tmem_objnode *objnode = NULL;
- unsigned long count;
- struct zcache_preload *kp;
-
- kp = &__get_cpu_var(zcache_preloads);
- if (kp->nr <= 0)
- goto out;
- objnode = kp->objnodes[kp->nr - 1];
- BUG_ON(objnode == NULL);
- kp->objnodes[kp->nr - 1] = NULL;
- kp->nr--;
- count = atomic_inc_return(&zcache_curr_objnode_count);
- if (count > zcache_curr_objnode_count_max)
- zcache_curr_objnode_count_max = count;
-out:
- return objnode;
-}
-
-static void zcache_objnode_free(struct tmem_objnode *objnode,
- struct tmem_pool *pool)
-{
- atomic_dec(&zcache_curr_objnode_count);
- BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0);
- kmem_cache_free(zcache_objnode_cache, objnode);
-}
-
-static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool)
-{
- struct tmem_obj *obj = NULL;
- unsigned long count;
- struct zcache_preload *kp;
-
- kp = &__get_cpu_var(zcache_preloads);
- obj = kp->obj;
- BUG_ON(obj == NULL);
- kp->obj = NULL;
- count = atomic_inc_return(&zcache_curr_obj_count);
- if (count > zcache_curr_obj_count_max)
- zcache_curr_obj_count_max = count;
- return obj;
-}
-
-static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
-{
- atomic_dec(&zcache_curr_obj_count);
- BUG_ON(atomic_read(&zcache_curr_obj_count) < 0);
- kmem_cache_free(zcache_obj_cache, obj);
-}
-
-static struct tmem_hostops zcache_hostops = {
- .obj_alloc = zcache_obj_alloc,
- .obj_free = zcache_obj_free,
- .objnode_alloc = zcache_objnode_alloc,
- .objnode_free = zcache_objnode_free,
-};
-
-/*
- * zcache implementations for PAM page descriptor ops
- */
-
-static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_eph_pampd_count_max;
-static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_pers_pampd_count_max;
-
-/* forward reference */
-static int zcache_compress(struct page *from, void **out_va, unsigned *out_len);
-
-static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
- struct tmem_pool *pool, struct tmem_oid *oid,
- uint32_t index)
-{
- void *pampd = NULL, *cdata;
- unsigned clen;
- int ret;
- unsigned long count;
- struct page *page = (struct page *)(data);
- struct zcache_client *cli = pool->client;
- uint16_t client_id = get_client_id_from_client(cli);
- unsigned long zv_mean_zsize;
- unsigned long curr_pers_pampd_count;
- u64 total_zsize;
-
- if (eph) {
- ret = zcache_compress(page, &cdata, &clen);
- if (ret == 0)
- goto out;
- if (clen == 0 || clen > zbud_max_buddy_size()) {
- zcache_compress_poor++;
- goto out;
- }
- pampd = (void *)zbud_create(client_id, pool->pool_id, oid,
- index, page, cdata, clen);
- if (pampd != NULL) {
- count = atomic_inc_return(&zcache_curr_eph_pampd_count);
- if (count > zcache_curr_eph_pampd_count_max)
- zcache_curr_eph_pampd_count_max = count;
- }
- } else {
- curr_pers_pampd_count =
- atomic_read(&zcache_curr_pers_pampd_count);
- if (curr_pers_pampd_count >
- (zv_page_count_policy_percent * totalram_pages) / 100)
- goto out;
- ret = zcache_compress(page, &cdata, &clen);
- if (ret == 0)
- goto out;
- /* reject if compression is too poor */
- if (clen > zv_max_zsize) {
- zcache_compress_poor++;
- goto out;
- }
- /* reject if mean compression is too poor */
- if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
- total_zsize = zs_get_total_size_bytes(cli->zspool);
- zv_mean_zsize = div_u64(total_zsize,
- curr_pers_pampd_count);
- if (zv_mean_zsize > zv_max_mean_zsize) {
- zcache_mean_compress_poor++;
- goto out;
- }
- }
- pampd = (void *)zv_create(cli->zspool, pool->pool_id,
- oid, index, cdata, clen);
- if (pampd == NULL)
- goto out;
- count = atomic_inc_return(&zcache_curr_pers_pampd_count);
- if (count > zcache_curr_pers_pampd_count_max)
- zcache_curr_pers_pampd_count_max = count;
- }
-out:
- return pampd;
-}
-
-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
-static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw,
- void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
-{
- int ret = 0;
-
- BUG_ON(is_ephemeral(pool));
- zv_decompress((struct page *)(data), (unsigned long)pampd);
- return ret;
-}
-
-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
-static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw,
- void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
-{
- BUG_ON(!is_ephemeral(pool));
- if (zbud_decompress((struct page *)(data), pampd) < 0)
- return -EINVAL;
- zbud_free_and_delist((struct zbud_hdr *)pampd);
- atomic_dec(&zcache_curr_eph_pampd_count);
- return 0;
-}
-
-/*
- * free the pampd and remove it from any zcache lists
- * pampd must no longer be pointed to from any tmem data structures!
- */
-static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
-{
- struct zcache_client *cli = pool->client;
-
- if (is_ephemeral(pool)) {
- zbud_free_and_delist((struct zbud_hdr *)pampd);
- atomic_dec(&zcache_curr_eph_pampd_count);
- BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0);
- } else {
- zv_free(cli->zspool, (unsigned long)pampd);
- atomic_dec(&zcache_curr_pers_pampd_count);
- BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0);
- }
-}
-
-static void zcache_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj)
-{
-}
-
-static void zcache_pampd_new_obj(struct tmem_obj *obj)
-{
-}
-
-static int zcache_pampd_replace_in_obj(void *pampd, struct tmem_obj *obj)
-{
- return -1;
-}
-
-static bool zcache_pampd_is_remote(void *pampd)
-{
- return 0;
-}
-
-static struct tmem_pamops zcache_pamops = {
- .create = zcache_pampd_create,
- .get_data = zcache_pampd_get_data,
- .get_data_and_free = zcache_pampd_get_data_and_free,
- .free = zcache_pampd_free,
- .free_obj = zcache_pampd_free_obj,
- .new_obj = zcache_pampd_new_obj,
- .replace_in_obj = zcache_pampd_replace_in_obj,
- .is_remote = zcache_pampd_is_remote,
-};
-
-/*
- * zcache compression/decompression and related per-cpu stuff
- */
-
-static DEFINE_PER_CPU(unsigned char *, zcache_dstmem);
-#define ZCACHE_DSTMEM_ORDER 1
-
-static int zcache_compress(struct page *from, void **out_va, unsigned *out_len)
-{
- int ret = 0;
- unsigned char *dmem = __get_cpu_var(zcache_dstmem);
- char *from_va;
-
- BUG_ON(!irqs_disabled());
- if (unlikely(dmem == NULL))
- goto out; /* no buffer or no compressor so can't compress */
- *out_len = PAGE_SIZE << ZCACHE_DSTMEM_ORDER;
- from_va = kmap_atomic(from);
- mb();
- ret = zcache_comp_op(ZCACHE_COMPOP_COMPRESS, from_va, PAGE_SIZE, dmem,
- out_len);
- BUG_ON(ret);
- *out_va = dmem;
- kunmap_atomic(from_va);
- ret = 1;
-out:
- return ret;
-}
-
-static int zcache_comp_cpu_up(int cpu)
-{
- struct crypto_comp *tfm;
-
- tfm = crypto_alloc_comp(zcache_comp_name, 0, 0);
- if (IS_ERR(tfm))
- return NOTIFY_BAD;
- *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = tfm;
- return NOTIFY_OK;
-}
-
-static void zcache_comp_cpu_down(int cpu)
-{
- struct crypto_comp *tfm;
-
- tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu);
- crypto_free_comp(tfm);
- *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = NULL;
-}
-
-static int zcache_cpu_notifier(struct notifier_block *nb,
- unsigned long action, void *pcpu)
-{
- int ret, cpu = (long)pcpu;
- struct zcache_preload *kp;
-
- switch (action) {
- case CPU_UP_PREPARE:
- ret = zcache_comp_cpu_up(cpu);
- if (ret != NOTIFY_OK) {
- pr_err("zcache: can't allocate compressor transform\n");
- return ret;
- }
- per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages(
- GFP_KERNEL | __GFP_REPEAT, ZCACHE_DSTMEM_ORDER);
- break;
- case CPU_DEAD:
- case CPU_UP_CANCELED:
- zcache_comp_cpu_down(cpu);
- free_pages((unsigned long)per_cpu(zcache_dstmem, cpu),
- ZCACHE_DSTMEM_ORDER);
- per_cpu(zcache_dstmem, cpu) = NULL;
- kp = &per_cpu(zcache_preloads, cpu);
- while (kp->nr) {
- kmem_cache_free(zcache_objnode_cache,
- kp->objnodes[kp->nr - 1]);
- kp->objnodes[kp->nr - 1] = NULL;
- kp->nr--;
- }
- if (kp->obj) {
- kmem_cache_free(zcache_obj_cache, kp->obj);
- kp->obj = NULL;
- }
- if (kp->page) {
- free_page((unsigned long)kp->page);
- kp->page = NULL;
- }
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block zcache_cpu_notifier_block = {
- .notifier_call = zcache_cpu_notifier
-};
-
-#ifdef CONFIG_SYSFS
-#define ZCACHE_SYSFS_RO(_name) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%lu\n", zcache_##_name); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-#define ZCACHE_SYSFS_RO_ATOMIC(_name) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return _func(buf); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-ZCACHE_SYSFS_RO(curr_obj_count_max);
-ZCACHE_SYSFS_RO(curr_objnode_count_max);
-ZCACHE_SYSFS_RO(flush_total);
-ZCACHE_SYSFS_RO(flush_found);
-ZCACHE_SYSFS_RO(flobj_total);
-ZCACHE_SYSFS_RO(flobj_found);
-ZCACHE_SYSFS_RO(failed_eph_puts);
-ZCACHE_SYSFS_RO(failed_pers_puts);
-ZCACHE_SYSFS_RO(zbud_curr_zbytes);
-ZCACHE_SYSFS_RO(zbud_cumul_zpages);
-ZCACHE_SYSFS_RO(zbud_cumul_zbytes);
-ZCACHE_SYSFS_RO(zbud_buddied_count);
-ZCACHE_SYSFS_RO(zbpg_unused_list_count);
-ZCACHE_SYSFS_RO(evicted_raw_pages);
-ZCACHE_SYSFS_RO(evicted_unbuddied_pages);
-ZCACHE_SYSFS_RO(evicted_buddied_pages);
-ZCACHE_SYSFS_RO(failed_get_free_pages);
-ZCACHE_SYSFS_RO(failed_alloc);
-ZCACHE_SYSFS_RO(put_to_flush);
-ZCACHE_SYSFS_RO(compress_poor);
-ZCACHE_SYSFS_RO(mean_compress_poor);
-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages);
-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages);
-ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count);
-ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count);
-ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts,
- zbud_show_unbuddied_list_counts);
-ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts,
- zbud_show_cumul_chunk_counts);
-ZCACHE_SYSFS_RO_CUSTOM(zv_curr_dist_counts,
- zv_curr_dist_counts_show);
-ZCACHE_SYSFS_RO_CUSTOM(zv_cumul_dist_counts,
- zv_cumul_dist_counts_show);
-
-static struct attribute *zcache_attrs[] = {
- &zcache_curr_obj_count_attr.attr,
- &zcache_curr_obj_count_max_attr.attr,
- &zcache_curr_objnode_count_attr.attr,
- &zcache_curr_objnode_count_max_attr.attr,
- &zcache_flush_total_attr.attr,
- &zcache_flobj_total_attr.attr,
- &zcache_flush_found_attr.attr,
- &zcache_flobj_found_attr.attr,
- &zcache_failed_eph_puts_attr.attr,
- &zcache_failed_pers_puts_attr.attr,
- &zcache_compress_poor_attr.attr,
- &zcache_mean_compress_poor_attr.attr,
- &zcache_zbud_curr_raw_pages_attr.attr,
- &zcache_zbud_curr_zpages_attr.attr,
- &zcache_zbud_curr_zbytes_attr.attr,
- &zcache_zbud_cumul_zpages_attr.attr,
- &zcache_zbud_cumul_zbytes_attr.attr,
- &zcache_zbud_buddied_count_attr.attr,
- &zcache_zbpg_unused_list_count_attr.attr,
- &zcache_evicted_raw_pages_attr.attr,
- &zcache_evicted_unbuddied_pages_attr.attr,
- &zcache_evicted_buddied_pages_attr.attr,
- &zcache_failed_get_free_pages_attr.attr,
- &zcache_failed_alloc_attr.attr,
- &zcache_put_to_flush_attr.attr,
- &zcache_zbud_unbuddied_list_counts_attr.attr,
- &zcache_zbud_cumul_chunk_counts_attr.attr,
- &zcache_zv_curr_dist_counts_attr.attr,
- &zcache_zv_cumul_dist_counts_attr.attr,
- &zcache_zv_max_zsize_attr.attr,
- &zcache_zv_max_mean_zsize_attr.attr,
- &zcache_zv_page_count_policy_percent_attr.attr,
- NULL,
-};
-
-static struct attribute_group zcache_attr_group = {
- .attrs = zcache_attrs,
- .name = "zcache",
-};
-
-#endif /* CONFIG_SYSFS */
-/*
- * When zcache is disabled ("frozen"), pools can be created and destroyed,
- * but all puts (and thus all other operations that require memory allocation)
- * must fail. If zcache is unfrozen, accepts puts, then frozen again,
- * data consistency requires all puts while frozen to be converted into
- * flushes.
- */
-static bool zcache_freeze;
-
-/*
- * zcache shrinker interface (only useful for ephemeral pages, so zbud only)
- */
-static int shrink_zcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
-{
- int ret = -1;
- int nr = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
-
- if (nr >= 0) {
- if (!(gfp_mask & __GFP_FS))
- /* does this case really need to be skipped? */
- goto out;
- zbud_evict_pages(nr);
- }
- ret = (int)atomic_read(&zcache_zbud_curr_raw_pages);
-out:
- return ret;
-}
-
-static struct shrinker zcache_shrinker = {
- .shrink = shrink_zcache_memory,
- .seeks = DEFAULT_SEEKS,
-};
-
-/*
- * zcache shims between cleancache/frontswap ops and tmem
- */
-
-static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, struct page *page)
-{
- struct tmem_pool *pool;
- int ret = -1;
-
- BUG_ON(!irqs_disabled());
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- if (unlikely(pool == NULL))
- goto out;
- if (!zcache_freeze && zcache_do_preload(pool) == 0) {
- /* preload does preempt_disable on success */
- ret = tmem_put(pool, oidp, index, (char *)(page),
- PAGE_SIZE, 0, is_ephemeral(pool));
- if (ret < 0) {
- if (is_ephemeral(pool))
- zcache_failed_eph_puts++;
- else
- zcache_failed_pers_puts++;
- }
- } else {
- zcache_put_to_flush++;
- if (atomic_read(&pool->obj_count) > 0)
- /* the put fails whether the flush succeeds or not */
- (void)tmem_flush_page(pool, oidp, index);
- }
-
- zcache_put_pool(pool);
-out:
- return ret;
-}
-
-static int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, struct page *page)
-{
- struct tmem_pool *pool;
- int ret = -1;
- unsigned long flags;
- size_t size = PAGE_SIZE;
-
- local_irq_save(flags);
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_get(pool, oidp, index, (char *)(page),
- &size, 0, is_ephemeral(pool));
- zcache_put_pool(pool);
- }
- local_irq_restore(flags);
- return ret;
-}
-
-static int zcache_flush_page(int cli_id, int pool_id,
- struct tmem_oid *oidp, uint32_t index)
-{
- struct tmem_pool *pool;
- int ret = -1;
- unsigned long flags;
-
- local_irq_save(flags);
- zcache_flush_total++;
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_flush_page(pool, oidp, index);
- zcache_put_pool(pool);
- }
- if (ret >= 0)
- zcache_flush_found++;
- local_irq_restore(flags);
- return ret;
-}
-
-static int zcache_flush_object(int cli_id, int pool_id,
- struct tmem_oid *oidp)
-{
- struct tmem_pool *pool;
- int ret = -1;
- unsigned long flags;
-
- local_irq_save(flags);
- zcache_flobj_total++;
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_flush_object(pool, oidp);
- zcache_put_pool(pool);
- }
- if (ret >= 0)
- zcache_flobj_found++;
- local_irq_restore(flags);
- return ret;
-}
-
-static int zcache_destroy_pool(int cli_id, int pool_id)
-{
- struct tmem_pool *pool = NULL;
- struct zcache_client *cli;
- int ret = -1;
-
- if (pool_id < 0)
- goto out;
-
- cli = get_zcache_client(cli_id);
- if (cli == NULL)
- goto out;
-
- atomic_inc(&cli->refcount);
- pool = idr_find(&cli->tmem_pools, pool_id);
- if (pool == NULL)
- goto out;
- idr_remove(&cli->tmem_pools, pool_id);
- /* wait for pool activity on other cpus to quiesce */
- while (atomic_read(&pool->refcount) != 0)
- ;
- atomic_dec(&cli->refcount);
- local_bh_disable();
- ret = tmem_destroy_pool(pool);
- local_bh_enable();
- kfree(pool);
- pr_info("zcache: destroyed pool id=%d, cli_id=%d\n",
- pool_id, cli_id);
-out:
- return ret;
-}
-
-static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
-{
- int poolid = -1;
- struct tmem_pool *pool;
- struct zcache_client *cli = NULL;
- int r;
-
- cli = get_zcache_client(cli_id);
- if (cli == NULL)
- goto out;
-
- atomic_inc(&cli->refcount);
- pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
- if (pool == NULL) {
- pr_info("zcache: pool creation failed: out of memory\n");
- goto out;
- }
-
- do {
- r = idr_pre_get(&cli->tmem_pools, GFP_ATOMIC);
- if (r != 1) {
- kfree(pool);
- pr_info("zcache: pool creation failed: out of memory\n");
- goto out;
- }
- r = idr_get_new(&cli->tmem_pools, pool, &poolid);
- } while (r == -EAGAIN);
- if (r) {
- pr_info("zcache: pool creation failed: error %d\n", r);
- kfree(pool);
- goto out;
- }
-
- atomic_set(&pool->refcount, 0);
- pool->client = cli;
- pool->pool_id = poolid;
- tmem_new_pool(pool, flags);
- pr_info("zcache: created %s tmem pool, id=%d, client=%d\n",
- flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
- poolid, cli_id);
-out:
- if (cli != NULL)
- atomic_dec(&cli->refcount);
- return poolid;
-}
-
-/**********
- * Two kernel functionalities currently can be layered on top of tmem.
- * These are "cleancache" which is used as a second-chance cache for clean
- * page cache pages; and "frontswap" which is used for swap pages
- * to avoid writes to disk. A generic "shim" is provided here for each
- * to translate in-kernel semantics to zcache semantics.
- */
-
-#ifdef CONFIG_CLEANCACHE
-static void zcache_cleancache_put_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index, struct page *page)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
- if (likely(ind == index))
- (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page);
-}
-
-static int zcache_cleancache_get_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index, struct page *page)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
- int ret = -1;
-
- if (likely(ind == index))
- ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page);
- return ret;
-}
-
-static void zcache_cleancache_flush_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
- if (likely(ind == index))
- (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind);
-}
-
-static void zcache_cleancache_flush_inode(int pool_id,
- struct cleancache_filekey key)
-{
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
- (void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid);
-}
-
-static void zcache_cleancache_flush_fs(int pool_id)
-{
- if (pool_id >= 0)
- (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id);
-}
-
-static int zcache_cleancache_init_fs(size_t pagesize)
-{
- BUG_ON(sizeof(struct cleancache_filekey) !=
- sizeof(struct tmem_oid));
- BUG_ON(pagesize != PAGE_SIZE);
- return zcache_new_pool(LOCAL_CLIENT, 0);
-}
-
-static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize)
-{
- /* shared pools are unsupported and map to private */
- BUG_ON(sizeof(struct cleancache_filekey) !=
- sizeof(struct tmem_oid));
- BUG_ON(pagesize != PAGE_SIZE);
- return zcache_new_pool(LOCAL_CLIENT, 0);
-}
-
-static struct cleancache_ops zcache_cleancache_ops = {
- .put_page = zcache_cleancache_put_page,
- .get_page = zcache_cleancache_get_page,
- .invalidate_page = zcache_cleancache_flush_page,
- .invalidate_inode = zcache_cleancache_flush_inode,
- .invalidate_fs = zcache_cleancache_flush_fs,
- .init_shared_fs = zcache_cleancache_init_shared_fs,
- .init_fs = zcache_cleancache_init_fs
-};
-
-struct cleancache_ops zcache_cleancache_register_ops(void)
-{
- struct cleancache_ops old_ops =
- cleancache_register_ops(&zcache_cleancache_ops);
-
- return old_ops;
-}
-#endif
-
-#ifdef CONFIG_FRONTSWAP
-/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
-static int zcache_frontswap_poolid = -1;
-
-/*
- * Swizzling increases objects per swaptype, increasing tmem concurrency
- * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS
- * Setting SWIZ_BITS to 27 basically reconstructs the swap entry from
- * frontswap_load(), but has side-effects. Hence using 8.
- */
-#define SWIZ_BITS 8
-#define SWIZ_MASK ((1 << SWIZ_BITS) - 1)
-#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))
-#define iswiz(_ind) (_ind >> SWIZ_BITS)
-
-static inline struct tmem_oid oswiz(unsigned type, u32 ind)
-{
- struct tmem_oid oid = { .oid = { 0 } };
- oid.oid[0] = _oswiz(type, ind);
- return oid;
-}
-
-static int zcache_frontswap_store(unsigned type, pgoff_t offset,
- struct page *page)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
- int ret = -1;
- unsigned long flags;
-
- BUG_ON(!PageLocked(page));
- if (likely(ind64 == ind)) {
- local_irq_save(flags);
- ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), page);
- local_irq_restore(flags);
- }
- return ret;
-}
-
-/* returns 0 if the page was successfully gotten from frontswap, -1 if
- * was not present (should never happen!) */
-static int zcache_frontswap_load(unsigned type, pgoff_t offset,
- struct page *page)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
- int ret = -1;
-
- BUG_ON(!PageLocked(page));
- if (likely(ind64 == ind))
- ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), page);
- return ret;
-}
-
-/* flush a single page from frontswap */
-static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
-
- if (likely(ind64 == ind))
- (void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind));
-}
-
-/* flush all pages from the passed swaptype */
-static void zcache_frontswap_flush_area(unsigned type)
-{
- struct tmem_oid oid;
- int ind;
-
- for (ind = SWIZ_MASK; ind >= 0; ind--) {
- oid = oswiz(type, ind);
- (void)zcache_flush_object(LOCAL_CLIENT,
- zcache_frontswap_poolid, &oid);
- }
-}
-
-static void zcache_frontswap_init(unsigned ignored)
-{
- /* a single tmem poolid is used for all frontswap "types" (swapfiles) */
- if (zcache_frontswap_poolid < 0)
- zcache_frontswap_poolid =
- zcache_new_pool(LOCAL_CLIENT, TMEM_POOL_PERSIST);
-}
-
-static struct frontswap_ops zcache_frontswap_ops = {
- .store = zcache_frontswap_store,
- .load = zcache_frontswap_load,
- .invalidate_page = zcache_frontswap_flush_page,
- .invalidate_area = zcache_frontswap_flush_area,
- .init = zcache_frontswap_init
-};
-
-struct frontswap_ops zcache_frontswap_register_ops(void)
-{
- struct frontswap_ops old_ops =
- frontswap_register_ops(&zcache_frontswap_ops);
-
- return old_ops;
-}
-#endif
-
-/*
- * zcache initialization
- * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR
- * NOTHING HAPPENS!
- */
-
-static int zcache_enabled;
-
-static int __init enable_zcache(char *s)
-{
- zcache_enabled = 1;
- return 1;
-}
-__setup("zcache", enable_zcache);
-
-/* allow independent dynamic disabling of cleancache and frontswap */
-
-static int use_cleancache = 1;
-
-static int __init no_cleancache(char *s)
-{
- use_cleancache = 0;
- return 1;
-}
-
-__setup("nocleancache", no_cleancache);
-
-static int use_frontswap = 1;
-
-static int __init no_frontswap(char *s)
-{
- use_frontswap = 0;
- return 1;
-}
-
-__setup("nofrontswap", no_frontswap);
-
-static int __init enable_zcache_compressor(char *s)
-{
- strncpy(zcache_comp_name, s, ZCACHE_COMP_NAME_SZ);
- zcache_enabled = 1;
- return 1;
-}
-__setup("zcache=", enable_zcache_compressor);
-
-
-static int __init zcache_comp_init(void)
-{
- int ret = 0;
-
- /* check crypto algorithm */
- if (*zcache_comp_name != '\0') {
- ret = crypto_has_comp(zcache_comp_name, 0, 0);
- if (!ret)
- pr_info("zcache: %s not supported\n",
- zcache_comp_name);
- }
- if (!ret)
- strcpy(zcache_comp_name, "lzo");
- ret = crypto_has_comp(zcache_comp_name, 0, 0);
- if (!ret) {
- ret = 1;
- goto out;
- }
- pr_info("zcache: using %s compressor\n", zcache_comp_name);
-
- /* alloc percpu transforms */
- ret = 0;
- zcache_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
- if (!zcache_comp_pcpu_tfms)
- ret = 1;
-out:
- return ret;
-}
-
-static int __init zcache_init(void)
-{
- int ret = 0;
-
-#ifdef CONFIG_SYSFS
- ret = sysfs_create_group(mm_kobj, &zcache_attr_group);
- if (ret) {
- pr_err("zcache: can't create sysfs\n");
- goto out;
- }
-#endif /* CONFIG_SYSFS */
-
- if (zcache_enabled) {
- unsigned int cpu;
-
- tmem_register_hostops(&zcache_hostops);
- tmem_register_pamops(&zcache_pamops);
- ret = register_cpu_notifier(&zcache_cpu_notifier_block);
- if (ret) {
- pr_err("zcache: can't register cpu notifier\n");
- goto out;
- }
- ret = zcache_comp_init();
- if (ret) {
- pr_err("zcache: compressor initialization failed\n");
- goto out;
- }
- for_each_online_cpu(cpu) {
- void *pcpu = (void *)(long)cpu;
- zcache_cpu_notifier(&zcache_cpu_notifier_block,
- CPU_UP_PREPARE, pcpu);
- }
- }
- zcache_objnode_cache = kmem_cache_create("zcache_objnode",
- sizeof(struct tmem_objnode), 0, 0, NULL);
- zcache_obj_cache = kmem_cache_create("zcache_obj",
- sizeof(struct tmem_obj), 0, 0, NULL);
- ret = zcache_new_client(LOCAL_CLIENT);
- if (ret) {
- pr_err("zcache: can't create client\n");
- goto out;
- }
-
-#ifdef CONFIG_CLEANCACHE
- if (zcache_enabled && use_cleancache) {
- struct cleancache_ops old_ops;
-
- zbud_init();
- register_shrinker(&zcache_shrinker);
- old_ops = zcache_cleancache_register_ops();
- pr_info("zcache: cleancache enabled using kernel "
- "transcendent memory and compression buddies\n");
- if (old_ops.init_fs != NULL)
- pr_warning("zcache: cleancache_ops overridden");
- }
-#endif
-#ifdef CONFIG_FRONTSWAP
- if (zcache_enabled && use_frontswap) {
- struct frontswap_ops old_ops;
-
- old_ops = zcache_frontswap_register_ops();
- pr_info("zcache: frontswap enabled using kernel "
- "transcendent memory and zsmalloc\n");
- if (old_ops.init != NULL)
- pr_warning("zcache: frontswap_ops overridden");
- }
-#endif
-out:
- return ret;
-}
-
-module_init(zcache_init)
projects / openwrt / staging / blogic.git / commitdiff