141 lines
3.1 KiB
C
141 lines
3.1 KiB
C
/*
|
|
* Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
|
|
* Authors: David Chinner and Glauber Costa
|
|
*
|
|
* Generic LRU infrastructure
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/list_lru.h>
|
|
#include <linux/slab.h>
|
|
|
|
bool list_lru_add(struct list_lru *lru, struct list_head *item)
|
|
{
|
|
int nid = page_to_nid(virt_to_page(item));
|
|
struct list_lru_node *nlru = &lru->node[nid];
|
|
|
|
spin_lock(&nlru->lock);
|
|
WARN_ON_ONCE(nlru->nr_items < 0);
|
|
if (list_empty(item)) {
|
|
list_add_tail(item, &nlru->list);
|
|
if (nlru->nr_items++ == 0)
|
|
node_set(nid, lru->active_nodes);
|
|
spin_unlock(&nlru->lock);
|
|
return true;
|
|
}
|
|
spin_unlock(&nlru->lock);
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_add);
|
|
|
|
bool list_lru_del(struct list_lru *lru, struct list_head *item)
|
|
{
|
|
int nid = page_to_nid(virt_to_page(item));
|
|
struct list_lru_node *nlru = &lru->node[nid];
|
|
|
|
spin_lock(&nlru->lock);
|
|
if (!list_empty(item)) {
|
|
list_del_init(item);
|
|
if (--nlru->nr_items == 0)
|
|
node_clear(nid, lru->active_nodes);
|
|
WARN_ON_ONCE(nlru->nr_items < 0);
|
|
spin_unlock(&nlru->lock);
|
|
return true;
|
|
}
|
|
spin_unlock(&nlru->lock);
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_del);
|
|
|
|
unsigned long
|
|
list_lru_count_node(struct list_lru *lru, int nid)
|
|
{
|
|
unsigned long count = 0;
|
|
struct list_lru_node *nlru = &lru->node[nid];
|
|
|
|
spin_lock(&nlru->lock);
|
|
WARN_ON_ONCE(nlru->nr_items < 0);
|
|
count += nlru->nr_items;
|
|
spin_unlock(&nlru->lock);
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_count_node);
|
|
|
|
unsigned long
|
|
list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate,
|
|
void *cb_arg, unsigned long *nr_to_walk)
|
|
{
|
|
|
|
struct list_lru_node *nlru = &lru->node[nid];
|
|
struct list_head *item, *n;
|
|
unsigned long isolated = 0;
|
|
|
|
spin_lock(&nlru->lock);
|
|
restart:
|
|
list_for_each_safe(item, n, &nlru->list) {
|
|
enum lru_status ret;
|
|
|
|
/*
|
|
* decrement nr_to_walk first so that we don't livelock if we
|
|
* get stuck on large numbesr of LRU_RETRY items
|
|
*/
|
|
if (!*nr_to_walk)
|
|
break;
|
|
--*nr_to_walk;
|
|
|
|
ret = isolate(item, &nlru->lock, cb_arg);
|
|
switch (ret) {
|
|
case LRU_REMOVED:
|
|
if (--nlru->nr_items == 0)
|
|
node_clear(nid, lru->active_nodes);
|
|
WARN_ON_ONCE(nlru->nr_items < 0);
|
|
isolated++;
|
|
break;
|
|
case LRU_ROTATE:
|
|
list_move_tail(item, &nlru->list);
|
|
break;
|
|
case LRU_SKIP:
|
|
break;
|
|
case LRU_RETRY:
|
|
/*
|
|
* The lru lock has been dropped, our list traversal is
|
|
* now invalid and so we have to restart from scratch.
|
|
*/
|
|
goto restart;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
spin_unlock(&nlru->lock);
|
|
return isolated;
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_walk_node);
|
|
|
|
int list_lru_init(struct list_lru *lru)
|
|
{
|
|
int i;
|
|
size_t size = sizeof(*lru->node) * nr_node_ids;
|
|
|
|
lru->node = kzalloc(size, GFP_KERNEL);
|
|
if (!lru->node)
|
|
return -ENOMEM;
|
|
|
|
nodes_clear(lru->active_nodes);
|
|
for (i = 0; i < nr_node_ids; i++) {
|
|
spin_lock_init(&lru->node[i].lock);
|
|
INIT_LIST_HEAD(&lru->node[i].list);
|
|
lru->node[i].nr_items = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_init);
|
|
|
|
void list_lru_destroy(struct list_lru *lru)
|
|
{
|
|
kfree(lru->node);
|
|
}
|
|
EXPORT_SYMBOL_GPL(list_lru_destroy);
|