return ret;
}
-/*
- * Calculate mapped_ratio under memory controller. This will be used in
- * vmscan.c for deteremining we have to reclaim mapped pages.
- */
-int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
-{
- long total, rss;
-
- /*
- * usage is recorded in bytes. But, here, we assume the number of
- * physical pages can be represented by "long" on any arch.
- */
- total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
- rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
- return (int)((rss * 100L) / total);
-}
-
/*
* prev_priority control...this will be used in memory reclaim path.
*/
return -ENOMEM;
}
+
+/*
+ * A helper function to get mem_cgroup from ID. must be called under
+ * rcu_read_lock(). The caller must check css_is_removed() or some if
+ * it's concern. (dropping refcnt from swap can be called against removed
+ * memcg.)
+ */
+static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
+{
+ struct cgroup_subsys_state *css;
+
+ /* ID 0 is unused ID */
+ if (!id)
+ return NULL;
+ css = css_lookup(&mem_cgroup_subsys, id);
+ if (!css)
+ return NULL;
+ return container_of(css, struct mem_cgroup, css);
+}
+
static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
{
struct mem_cgroup *mem;
+ struct page_cgroup *pc;
+ unsigned short id;
swp_entry_t ent;
+ VM_BUG_ON(!PageLocked(page));
+
if (!PageSwapCache(page))
return NULL;
- ent.val = page_private(page);
- mem = lookup_swap_cgroup(ent);
- if (!mem)
- return NULL;
- if (!css_tryget(&mem->css))
- return NULL;
+ pc = lookup_page_cgroup(page);
+ /*
+ * Used bit of swapcache is solid under page lock.
+ */
+ if (PageCgroupUsed(pc)) {
+ mem = pc->mem_cgroup;
+ if (mem && !css_tryget(&mem->css))
+ mem = NULL;
+ } else {
+ ent.val = page_private(page);
+ id = lookup_swap_cgroup(ent);
+ rcu_read_lock();
+ mem = mem_cgroup_lookup(id);
+ if (mem && !css_tryget(&mem->css))
+ mem = NULL;
+ rcu_read_unlock();
+ }
return mem;
}
MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
}
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+ enum charge_type ctype);
+
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask)
{
unlock_page_cgroup(pc);
}
- if (do_swap_account && PageSwapCache(page)) {
- mem = try_get_mem_cgroup_from_swapcache(page);
- if (mem)
- mm = NULL;
- else
- mem = NULL;
- /* SwapCache may be still linked to LRU now. */
- mem_cgroup_lru_del_before_commit_swapcache(page);
- }
-
if (unlikely(!mm && !mem))
mm = &init_mm;
return mem_cgroup_charge_common(page, mm, gfp_mask,
MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
- ret = mem_cgroup_charge_common(page, mm, gfp_mask,
- MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
- if (mem)
- css_put(&mem->css);
- if (PageSwapCache(page))
- mem_cgroup_lru_add_after_commit_swapcache(page);
+ /* shmem */
+ if (PageSwapCache(page)) {
+ ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+ if (!ret)
+ __mem_cgroup_commit_charge_swapin(page, mem,
+ MEM_CGROUP_CHARGE_TYPE_SHMEM);
+ } else
+ ret = mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
- if (do_swap_account && !ret && PageSwapCache(page)) {
- swp_entry_t ent = {.val = page_private(page)};
- /* avoid double counting */
- mem = swap_cgroup_record(ent, NULL);
- if (mem) {
- res_counter_uncharge(&mem->memsw, PAGE_SIZE);
- mem_cgroup_put(mem);
- }
- }
return ret;
}
return __mem_cgroup_try_charge(mm, mask, ptr, true);
}
-void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+ enum charge_type ctype)
{
struct page_cgroup *pc;
return;
pc = lookup_page_cgroup(page);
mem_cgroup_lru_del_before_commit_swapcache(page);
- __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
+ __mem_cgroup_commit_charge(ptr, pc, ctype);
mem_cgroup_lru_add_after_commit_swapcache(page);
/*
* Now swap is on-memory. This means this page may be
*/
if (do_swap_account && PageSwapCache(page)) {
swp_entry_t ent = {.val = page_private(page)};
+ unsigned short id;
struct mem_cgroup *memcg;
- memcg = swap_cgroup_record(ent, NULL);
+
+ id = swap_cgroup_record(ent, 0);
+ rcu_read_lock();
+ memcg = mem_cgroup_lookup(id);
if (memcg) {
+ /*
+ * This recorded memcg can be obsolete one. So, avoid
+ * calling css_tryget
+ */
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
mem_cgroup_put(memcg);
}
-
+ rcu_read_unlock();
}
/* add this page(page_cgroup) to the LRU we want. */
}
+void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+{
+ __mem_cgroup_commit_charge_swapin(page, ptr,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
{
if (mem_cgroup_disabled())
MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
/* record memcg information */
if (do_swap_account && memcg) {
- swap_cgroup_record(ent, memcg);
+ swap_cgroup_record(ent, css_id(&memcg->css));
mem_cgroup_get(memcg);
}
if (memcg)
void mem_cgroup_uncharge_swap(swp_entry_t ent)
{
struct mem_cgroup *memcg;
+ unsigned short id;
if (!do_swap_account)
return;
- memcg = swap_cgroup_record(ent, NULL);
+ id = swap_cgroup_record(ent, 0);
+ rcu_read_lock();
+ memcg = mem_cgroup_lookup(id);
if (memcg) {
+ /*
+ * We uncharge this because swap is freed.
+ * This memcg can be obsolete one. We avoid calling css_tryget
+ */
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
mem_cgroup_put(memcg);
}
+ rcu_read_unlock();
}
#endif