if (unlikely(!mem))
return 0;
- VM_BUG_ON(mem_cgroup_is_obsolete(mem));
+ VM_BUG_ON(!mem || mem_cgroup_is_obsolete(mem));
while (1) {
int ret;
return NULL;
pc = lookup_page_cgroup(page);
- /*
- * Used bit of swapcache is solid under page lock.
- */
+ lock_page_cgroup(pc);
if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
if (mem && !css_tryget(&mem->css))
mem = NULL;
rcu_read_unlock();
}
+ unlock_page_cgroup(pc);
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)};
- unsigned short id;
- /* avoid double counting */
- id = swap_cgroup_record(ent, 0);
- rcu_read_lock();
- mem = mem_cgroup_lookup(id);
- if (mem) {
- /*
- * We did swap-in. Then, this entry is doubly counted
- * both in mem and memsw. We uncharge it, here.
- * Recorded ID can be obsolete. We avoid calling
- * css_tryget()
- */
- res_counter_uncharge(&mem->memsw, PAGE_SIZE);
- mem_cgroup_put(mem);
- }
- rcu_read_unlock();
- }
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
}
+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())
}
/*
- * A call to try to shrink memory usage under specified resource controller.
- * This is typically used for page reclaiming for shmem for reducing side
- * effect of page allocation from shmem, which is used by some mem_cgroup.
+ * A call to try to shrink memory usage on charge failure at shmem's swapin.
+ * Calling hierarchical_reclaim is not enough because we should update
+ * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
+ * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
+ * not from the memcg which this page would be charged to.
+ * try_charge_swapin does all of these works properly.
*/
-int mem_cgroup_shrink_usage(struct page *page,
+int mem_cgroup_shmem_charge_fallback(struct page *page,
struct mm_struct *mm,
gfp_t gfp_mask)
{
struct mem_cgroup *mem = NULL;
- int progress = 0;
- int retry = MEM_CGROUP_RECLAIM_RETRIES;
+ int ret;
if (mem_cgroup_disabled())
return 0;
- if (page)
- mem = try_get_mem_cgroup_from_swapcache(page);
- if (!mem && mm)
- mem = try_get_mem_cgroup_from_mm(mm);
- if (unlikely(!mem))
- return 0;
- do {
- progress = mem_cgroup_hierarchical_reclaim(mem,
- gfp_mask, true, false);
- progress += mem_cgroup_check_under_limit(mem);
- } while (!progress && --retry);
+ ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+ if (!ret)
+ mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
- css_put(&mem->css);
- if (!retry)
- return -ENOMEM;
- return 0;
+ return ret;
}
static DEFINE_MUTEX(set_limit_mutex);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff