}
static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz,
- struct page_cgroup *pc)
+ struct page_cgroup *pc, bool hot)
{
int lru = LRU_BASE;
}
MEM_CGROUP_ZSTAT(mz, lru) += 1;
- list_add(&pc->lru, &mz->lists[lru]);
+ if (hot)
+ list_add(&pc->lru, &mz->lists[lru]);
+ else
+ list_add_tail(&pc->lru, &mz->lists[lru]);
mem_cgroup_charge_statistics(pc->mem_cgroup, pc, true);
}
return nr_taken;
}
-
-/**
- * mem_cgroup_try_charge - get charge of PAGE_SIZE.
- * @mm: an mm_struct which is charged against. (when *memcg is NULL)
- * @gfp_mask: gfp_mask for reclaim.
- * @memcg: a pointer to memory cgroup which is charged against.
- *
- * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
- * memory cgroup from @mm is got and stored in *memcg.
- *
- * Returns 0 if success. -ENOMEM at failure.
+/*
+ * Unlike exported interface, "oom" parameter is added. if oom==true,
+ * oom-killer can be invoked.
*/
-
-int mem_cgroup_try_charge(struct mm_struct *mm,
- gfp_t gfp_mask, struct mem_cgroup **memcg)
+static int __mem_cgroup_try_charge(struct mm_struct *mm,
+ gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom)
{
struct mem_cgroup *mem;
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
continue;
if (!nr_retries--) {
- mem_cgroup_out_of_memory(mem, gfp_mask);
+ if (oom)
+ mem_cgroup_out_of_memory(mem, gfp_mask);
goto nomem;
}
}
return -ENOMEM;
}
+/**
+ * mem_cgroup_try_charge - get charge of PAGE_SIZE.
+ * @mm: an mm_struct which is charged against. (when *memcg is NULL)
+ * @gfp_mask: gfp_mask for reclaim.
+ * @memcg: a pointer to memory cgroup which is charged against.
+ *
+ * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
+ * memory cgroup from @mm is got and stored in *memcg.
+ *
+ * Returns 0 if success. -ENOMEM at failure.
+ * This call can invoke OOM-Killer.
+ */
+
+int mem_cgroup_try_charge(struct mm_struct *mm,
+ gfp_t mask, struct mem_cgroup **memcg)
+{
+ return __mem_cgroup_try_charge(mm, mask, memcg, true);
+}
+
/*
* commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
* USED state. If already USED, uncharge and return.
mz = page_cgroup_zoneinfo(pc);
spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_add_list(mz, pc);
+ __mem_cgroup_add_list(mz, pc, true);
spin_unlock_irqrestore(&mz->lru_lock, flags);
unlock_page_cgroup(pc);
}
+/**
+ * mem_cgroup_move_account - move account of the page
+ * @pc: page_cgroup of the page.
+ * @from: mem_cgroup which the page is moved from.
+ * @to: mem_cgroup which the page is moved to. @from != @to.
+ *
+ * The caller must confirm following.
+ * 1. disable irq.
+ * 2. lru_lock of old mem_cgroup(@from) should be held.
+ *
+ * returns 0 at success,
+ * returns -EBUSY when lock is busy or "pc" is unstable.
+ *
+ * This function does "uncharge" from old cgroup but doesn't do "charge" to
+ * new cgroup. It should be done by a caller.
+ */
+
+static int mem_cgroup_move_account(struct page_cgroup *pc,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ struct mem_cgroup_per_zone *from_mz, *to_mz;
+ int nid, zid;
+ int ret = -EBUSY;
+
+ VM_BUG_ON(!irqs_disabled());
+ VM_BUG_ON(from == to);
+
+ nid = page_cgroup_nid(pc);
+ zid = page_cgroup_zid(pc);
+ from_mz = mem_cgroup_zoneinfo(from, nid, zid);
+ to_mz = mem_cgroup_zoneinfo(to, nid, zid);
+
+
+ if (!trylock_page_cgroup(pc))
+ return ret;
+
+ if (!PageCgroupUsed(pc))
+ goto out;
+
+ if (pc->mem_cgroup != from)
+ goto out;
+
+ if (spin_trylock(&to_mz->lru_lock)) {
+ __mem_cgroup_remove_list(from_mz, pc);
+ css_put(&from->css);
+ res_counter_uncharge(&from->res, PAGE_SIZE);
+ pc->mem_cgroup = to;
+ css_get(&to->css);
+ __mem_cgroup_add_list(to_mz, pc, false);
+ ret = 0;
+ spin_unlock(&to_mz->lru_lock);
+ }
+out:
+ unlock_page_cgroup(pc);
+ return ret;
+}
+
+/*
+ * move charges to its parent.
+ */
+
+static int mem_cgroup_move_parent(struct page_cgroup *pc,
+ struct mem_cgroup *child,
+ gfp_t gfp_mask)
+{
+ struct cgroup *cg = child->css.cgroup;
+ struct cgroup *pcg = cg->parent;
+ struct mem_cgroup *parent;
+ struct mem_cgroup_per_zone *mz;
+ unsigned long flags;
+ int ret;
+
+ /* Is ROOT ? */
+ if (!pcg)
+ return -EINVAL;
+
+ parent = mem_cgroup_from_cont(pcg);
+
+ ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
+ if (ret)
+ return ret;
+
+ mz = mem_cgroup_zoneinfo(child,
+ page_cgroup_nid(pc), page_cgroup_zid(pc));
+
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ ret = mem_cgroup_move_account(pc, child, parent);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+
+ /* drop extra refcnt */
+ css_put(&parent->css);
+ /* uncharge if move fails */
+ if (ret)
+ res_counter_uncharge(&parent->res, PAGE_SIZE);
+
+ return ret;
+}
+
/*
* Charge the memory controller for page usage.
* Return
prefetchw(pc);
mem = memcg;
- ret = mem_cgroup_try_charge(mm, gfp_mask, &mem);
+ ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
if (ret)
return ret;
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
*/
-#define FORCE_UNCHARGE_BATCH (128)
-static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
+static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
struct mem_cgroup_per_zone *mz,
enum lru_list lru)
{
- struct page_cgroup *pc;
- struct page *page;
- int count = FORCE_UNCHARGE_BATCH;
+ struct page_cgroup *pc, *busy;
unsigned long flags;
+ unsigned long loop;
struct list_head *list;
+ int ret = 0;
list = &mz->lists[lru];
- spin_lock_irqsave(&mz->lru_lock, flags);
- while (!list_empty(list)) {
- pc = list_entry(list->prev, struct page_cgroup, lru);
- page = pc->page;
- if (!PageCgroupUsed(pc))
+ loop = MEM_CGROUP_ZSTAT(mz, lru);
+ /* give some margin against EBUSY etc...*/
+ loop += 256;
+ busy = NULL;
+ while (loop--) {
+ ret = 0;
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ if (list_empty(list)) {
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
break;
- get_page(page);
+ }
+ pc = list_entry(list->prev, struct page_cgroup, lru);
+ if (busy == pc) {
+ list_move(&pc->lru, list);
+ busy = 0;
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+ continue;
+ }
spin_unlock_irqrestore(&mz->lru_lock, flags);
- /*
- * Check if this page is on LRU. !LRU page can be found
- * if it's under page migration.
- */
- if (PageLRU(page)) {
- __mem_cgroup_uncharge_common(page,
- MEM_CGROUP_CHARGE_TYPE_FORCE);
- put_page(page);
- if (--count <= 0) {
- count = FORCE_UNCHARGE_BATCH;
- cond_resched();
- }
- } else {
- spin_lock_irqsave(&mz->lru_lock, flags);
+
+ ret = mem_cgroup_move_parent(pc, mem, GFP_HIGHUSER_MOVABLE);
+ if (ret == -ENOMEM)
break;
- }
- spin_lock_irqsave(&mz->lru_lock, flags);
+
+ if (ret == -EBUSY || ret == -EINVAL) {
+ /* found lock contention or "pc" is obsolete. */
+ busy = pc;
+ cond_resched();
+ } else
+ busy = NULL;
}
- spin_unlock_irqrestore(&mz->lru_lock, flags);
+ if (!ret && !list_empty(list))
+ return -EBUSY;
+ return ret;
}
/*
*/
static int mem_cgroup_force_empty(struct mem_cgroup *mem)
{
- int ret = -EBUSY;
- int node, zid;
+ int ret;
+ int node, zid, shrink;
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
css_get(&mem->css);
- /*
- * page reclaim code (kswapd etc..) will move pages between
- * active_list <-> inactive_list while we don't take a lock.
- * So, we have to do loop here until all lists are empty.
- */
+
+ shrink = 0;
+move_account:
while (mem->res.usage > 0) {
+ ret = -EBUSY;
if (atomic_read(&mem->css.cgroup->count) > 0)
goto out;
+
/* This is for making all *used* pages to be on LRU. */
lru_add_drain_all();
- for_each_node_state(node, N_POSSIBLE)
- for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ ret = 0;
+ for_each_node_state(node, N_POSSIBLE) {
+ for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
struct mem_cgroup_per_zone *mz;
enum lru_list l;
mz = mem_cgroup_zoneinfo(mem, node, zid);
- for_each_lru(l)
- mem_cgroup_force_empty_list(mem, mz, l);
+ for_each_lru(l) {
+ ret = mem_cgroup_force_empty_list(mem,
+ mz, l);
+ if (ret)
+ break;
+ }
}
+ if (ret)
+ break;
+ }
+ /* it seems parent cgroup doesn't have enough mem */
+ if (ret == -ENOMEM)
+ goto try_to_free;
cond_resched();
}
ret = 0;
out:
css_put(&mem->css);
return ret;
+
+try_to_free:
+ /* returns EBUSY if we come here twice. */
+ if (shrink) {
+ ret = -EBUSY;
+ goto out;
+ }
+ /* try to free all pages in this cgroup */
+ shrink = 1;
+ while (nr_retries && mem->res.usage > 0) {
+ int progress;
+ progress = try_to_free_mem_cgroup_pages(mem,
+ GFP_HIGHUSER_MOVABLE);
+ if (!progress)
+ nr_retries--;
+
+ }
+ /* try move_account...there may be some *locked* pages. */
+ if (mem->res.usage)
+ goto move_account;
+ ret = 0;
+ goto out;
}
static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
return 0;
}
-static int mem_force_empty_write(struct cgroup *cont, unsigned int event)
-{
- return mem_cgroup_force_empty(mem_cgroup_from_cont(cont));
-}
-
static const struct mem_cgroup_stat_desc {
const char *msg;
u64 unit;
.trigger = mem_cgroup_reset,
.read_u64 = mem_cgroup_read,
},
- {
- .name = "force_empty",
- .trigger = mem_force_empty_write,
- },
{
.name = "stat",
.read_map = mem_control_stat_show,
projects / openwrt / staging / blogic.git / commitdiff