/*
* In-kernel transcendent memory (generic implementation)
*
* Copyright (c) 2009-2011, Dan Magenheimer, Oracle Corp.
*
* The primary purpose of Transcedent 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.
*/
/* 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)
{
struct rb_node *rbnode;
struct tmem_obj *obj;
rbnode = hb->obj_rb_root.rb_node;
while (rbnode) {
BUG_ON(RB_EMPTY_NODE(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;
}
}
obj = NULL;
out:
return obj;
}
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 = &(root->rb_node), *parent = NULL;
struct tmem_obj *this;
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);
while (*new) {
BUG_ON(RB_EMPTY_NODE(*new));
this = rb_entry(*new, struct tmem_obj, rb_tree_node);
parent = *new;
switch (tmem_oid_compare(oidp, &this->oid)) {
case 0:
BUG(); /* already present; should never happen! */
break;
case -1:
new = &(*new)->rb_left;
break;
case 1:
new = &(*new)->rb_right;
break;
}
}
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;
}
