#include <linux/spinlock.h>
#include <linux/fs.h>
+#include <asm/uaccess.h>
+
struct cgroup_subsys mem_cgroup_subsys;
static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
* spin_lock to protect the per cgroup LRU
*/
spinlock_t lru_lock;
+ unsigned long control_type; /* control RSS or RSS+Pagecache */
};
/*
/* mapped and cached states */
};
+enum {
+ MEM_CGROUP_TYPE_UNSPEC = 0,
+ MEM_CGROUP_TYPE_MAPPED,
+ MEM_CGROUP_TYPE_CACHED,
+ MEM_CGROUP_TYPE_ALL,
+ MEM_CGROUP_TYPE_MAX,
+};
+
+static struct mem_cgroup init_mem_cgroup;
static inline
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
(page->page_cgroup & ~PAGE_CGROUP_LOCK);
}
-void __always_inline lock_page_cgroup(struct page *page)
+static void __always_inline lock_page_cgroup(struct page *page)
{
bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
VM_BUG_ON(!page_cgroup_locked(page));
}
-void __always_inline unlock_page_cgroup(struct page *page)
+static void __always_inline unlock_page_cgroup(struct page *page)
{
bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
}
-void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
+/*
+ * Tie new page_cgroup to struct page under lock_page_cgroup()
+ * This can fail if the page has been tied to a page_cgroup.
+ * If success, returns 0.
+ */
+static inline int
+page_cgroup_assign_new_page_cgroup(struct page *page, struct page_cgroup *pc)
+{
+ int ret = 0;
+
+ lock_page_cgroup(page);
+ if (!page_get_page_cgroup(page))
+ page_assign_page_cgroup(page, pc);
+ else /* A page is tied to other pc. */
+ ret = 1;
+ unlock_page_cgroup(page);
+ return ret;
+}
+
+/*
+ * Clear page->page_cgroup member under lock_page_cgroup().
+ * If given "pc" value is different from one page->page_cgroup,
+ * page->cgroup is not cleared.
+ * Returns a value of page->page_cgroup at lock taken.
+ * A can can detect failure of clearing by following
+ * clear_page_cgroup(page, pc) == pc
+ */
+
+static inline struct page_cgroup *
+clear_page_cgroup(struct page *page, struct page_cgroup *pc)
+{
+ struct page_cgroup *ret;
+ /* lock and clear */
+ lock_page_cgroup(page);
+ ret = page_get_page_cgroup(page);
+ if (likely(ret == pc))
+ page_assign_page_cgroup(page, NULL);
+ unlock_page_cgroup(page);
+ return ret;
+}
+
+
+static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
{
if (active)
list_move(&pc->lru, &pc->mem_cgroup->active_list);
list_move(&pc->lru, &pc->mem_cgroup->inactive_list);
}
+int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
+{
+ int ret;
+
+ task_lock(task);
+ ret = task->mm && mm_cgroup(task->mm) == mem;
+ task_unlock(task);
+ return ret;
+}
+
/*
* This routine assumes that the appropriate zone's lru lock is already held
*/
* 0 if the charge was successful
* < 0 if the cgroup is over its limit
*/
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask)
{
struct mem_cgroup *mem;
- struct page_cgroup *pc, *race_pc;
+ struct page_cgroup *pc;
unsigned long flags;
unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
unlock_page_cgroup(page);
cpu_relax();
goto retry;
- } else
+ } else {
+ unlock_page_cgroup(page);
goto done;
+ }
}
unlock_page_cgroup(page);
- pc = kzalloc(sizeof(struct page_cgroup), GFP_KERNEL);
+ pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
if (pc == NULL)
goto err;
* the cgroup limit.
*/
while (res_counter_charge(&mem->res, PAGE_SIZE)) {
- if (try_to_free_mem_cgroup_pages(mem))
+ bool is_atomic = gfp_mask & GFP_ATOMIC;
+ /*
+ * We cannot reclaim under GFP_ATOMIC, fail the charge
+ */
+ if (is_atomic)
+ goto noreclaim;
+
+ if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
continue;
/*
congestion_wait(WRITE, HZ/10);
continue;
}
-
+noreclaim:
css_put(&mem->css);
+ if (!is_atomic)
+ mem_cgroup_out_of_memory(mem, GFP_KERNEL);
goto free_pc;
}
- lock_page_cgroup(page);
- /*
- * Check if somebody else beat us to allocating the page_cgroup
- */
- race_pc = page_get_page_cgroup(page);
- if (race_pc) {
- kfree(pc);
- pc = race_pc;
- atomic_inc(&pc->ref_cnt);
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- css_put(&mem->css);
- goto done;
- }
-
atomic_set(&pc->ref_cnt, 1);
pc->mem_cgroup = mem;
pc->page = page;
- page_assign_page_cgroup(page, pc);
+ if (page_cgroup_assign_new_page_cgroup(page, pc)) {
+ /*
+ * an another charge is added to this page already.
+ * we do take lock_page_cgroup(page) again and read
+ * page->cgroup, increment refcnt.... just retry is OK.
+ */
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
+ css_put(&mem->css);
+ kfree(pc);
+ goto retry;
+ }
spin_lock_irqsave(&mem->lru_lock, flags);
list_add(&pc->lru, &mem->active_list);
spin_unlock_irqrestore(&mem->lru_lock, flags);
done:
- unlock_page_cgroup(page);
return 0;
free_pc:
kfree(pc);
return -ENOMEM;
}
+/*
+ * See if the cached pages should be charged at all?
+ */
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask)
+{
+ struct mem_cgroup *mem;
+ if (!mm)
+ mm = &init_mm;
+
+ mem = rcu_dereference(mm->mem_cgroup);
+ if (mem->control_type == MEM_CGROUP_TYPE_ALL)
+ return mem_cgroup_charge(page, mm, gfp_mask);
+ else
+ return 0;
+}
+
/*
* Uncharging is always a welcome operation, we never complain, simply
* uncharge.
struct page *page;
unsigned long flags;
+ /*
+ * This can handle cases when a page is not charged at all and we
+ * are switching between handling the control_type.
+ */
if (!pc)
return;
if (atomic_dec_and_test(&pc->ref_cnt)) {
page = pc->page;
- lock_page_cgroup(page);
- mem = pc->mem_cgroup;
- css_put(&mem->css);
- page_assign_page_cgroup(page, NULL);
- unlock_page_cgroup(page);
- res_counter_uncharge(&mem->res, PAGE_SIZE);
-
- spin_lock_irqsave(&mem->lru_lock, flags);
- list_del_init(&pc->lru);
- spin_unlock_irqrestore(&mem->lru_lock, flags);
- kfree(pc);
+ /*
+ * get page->cgroup and clear it under lock.
+ */
+ if (clear_page_cgroup(page, pc) == pc) {
+ mem = pc->mem_cgroup;
+ css_put(&mem->css);
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
+ spin_lock_irqsave(&mem->lru_lock, flags);
+ list_del_init(&pc->lru);
+ spin_unlock_irqrestore(&mem->lru_lock, flags);
+ kfree(pc);
+ } else {
+ /*
+ * Note:This will be removed when force-empty patch is
+ * applied. just show warning here.
+ */
+ printk(KERN_ERR "Race in mem_cgroup_uncharge() ?");
+ dump_stack();
+ }
}
}
+/*
+ * Returns non-zero if a page (under migration) has valid page_cgroup member.
+ * Refcnt of page_cgroup is incremented.
+ */
+
+int mem_cgroup_prepare_migration(struct page *page)
+{
+ struct page_cgroup *pc;
+ int ret = 0;
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
+ if (pc && atomic_inc_not_zero(&pc->ref_cnt))
+ ret = 1;
+ unlock_page_cgroup(page);
+ return ret;
+}
+
+void mem_cgroup_end_migration(struct page *page)
+{
+ struct page_cgroup *pc = page_get_page_cgroup(page);
+ mem_cgroup_uncharge(pc);
+}
+/*
+ * We know both *page* and *newpage* are now not-on-LRU and Pg_locked.
+ * And no race with uncharge() routines because page_cgroup for *page*
+ * has extra one reference by mem_cgroup_prepare_migration.
+ */
+
+void mem_cgroup_page_migration(struct page *page, struct page *newpage)
+{
+ struct page_cgroup *pc;
+retry:
+ pc = page_get_page_cgroup(page);
+ if (!pc)
+ return;
+ if (clear_page_cgroup(page, pc) != pc)
+ goto retry;
+ pc->page = newpage;
+ lock_page_cgroup(newpage);
+ page_assign_page_cgroup(newpage, pc);
+ unlock_page_cgroup(newpage);
+ return;
+}
int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp)
{
mem_cgroup_write_strategy);
}
+static ssize_t mem_control_type_write(struct cgroup *cont,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *pos)
+{
+ int ret;
+ char *buf, *end;
+ unsigned long tmp;
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cont);
+ buf = kmalloc(nbytes + 1, GFP_KERNEL);
+ ret = -ENOMEM;
+ if (buf == NULL)
+ goto out;
+
+ buf[nbytes] = 0;
+ ret = -EFAULT;
+ if (copy_from_user(buf, userbuf, nbytes))
+ goto out_free;
+
+ ret = -EINVAL;
+ tmp = simple_strtoul(buf, &end, 10);
+ if (*end != '\0')
+ goto out_free;
+
+ if (tmp <= MEM_CGROUP_TYPE_UNSPEC || tmp >= MEM_CGROUP_TYPE_MAX)
+ goto out_free;
+
+ mem->control_type = tmp;
+ ret = nbytes;
+out_free:
+ kfree(buf);
+out:
+ return ret;
+}
+
+static ssize_t mem_control_type_read(struct cgroup *cont,
+ struct cftype *cft,
+ struct file *file, char __user *userbuf,
+ size_t nbytes, loff_t *ppos)
+{
+ unsigned long val;
+ char buf[64], *s;
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cont);
+ s = buf;
+ val = mem->control_type;
+ s += sprintf(s, "%lu\n", val);
+ return simple_read_from_buffer((void __user *)userbuf, nbytes,
+ ppos, buf, s - buf);
+}
+
static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
.private = RES_FAILCNT,
.read = mem_cgroup_read,
},
+ {
+ .name = "control_type",
+ .write = mem_control_type_write,
+ .read = mem_control_type_read,
+ },
};
static struct mem_cgroup init_mem_cgroup;
INIT_LIST_HEAD(&mem->active_list);
INIT_LIST_HEAD(&mem->inactive_list);
spin_lock_init(&mem->lru_lock);
+ mem->control_type = MEM_CGROUP_TYPE_ALL;
return &mem->css;
}
projects / powerpc.git / blobdiff