#include <linux/limits.h>
#include <linux/mutex.h>
#include <linux/rbtree.h>
-#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/swapops.h>
mem_cgroup_add_lru_list(page, to);
}
+/*
+ * Checks whether given mem is same or in the root_mem's
+ * hierarchy subtree
+ */
+static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_mem,
+ struct mem_cgroup *mem)
+{
+ if (root_mem != mem) {
+ return (root_mem->use_hierarchy &&
+ css_is_ancestor(&mem->css, &root_mem->css));
+ }
+
+ return true;
+}
+
int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
{
int ret;
* enabled in "curr" and "curr" is a child of "mem" in *cgroup*
* hierarchy(even if use_hierarchy is disabled in "mem").
*/
- if (mem->use_hierarchy)
- ret = css_is_ancestor(&curr->css, &mem->css);
- else
- ret = (curr == mem);
+ ret = mem_cgroup_same_or_subtree(mem, curr);
css_put(&curr->css);
return ret;
}
to = mc.to;
if (!from)
goto unlock;
- if (from == mem || to == mem
- || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
- || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
- ret = true;
+
+ ret = mem_cgroup_same_or_subtree(mem, from)
+ || mem_cgroup_same_or_subtree(mem, to);
unlock:
spin_unlock(&mc.lock);
return ret;
static int memcg_oom_wake_function(wait_queue_t *wait,
unsigned mode, int sync, void *arg)
{
- struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
+ struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg,
+ *oom_wait_mem;
struct oom_wait_info *oom_wait_info;
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+ oom_wait_mem = oom_wait_info->mem;
- if (oom_wait_info->mem == wake_mem)
- goto wakeup;
- /* if no hierarchy, no match */
- if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
- return 0;
/*
* Both of oom_wait_info->mem and wake_mem are stable under us.
* Then we can use css_is_ancestor without taking care of RCU.
*/
- if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
- !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
+ if (!mem_cgroup_same_or_subtree(oom_wait_mem, wake_mem)
+ && !mem_cgroup_same_or_subtree(wake_mem, oom_wait_mem))
return 0;
-
-wakeup:
return autoremove_wake_function(wait, mode, sync, arg);
}
#define FLUSHING_CACHED_CHARGE (0)
};
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
-static DEFINE_MUTEX(percpu_charge_mutex);
/*
* Try to consume stocked charge on this cpu. If success, one page is consumed
}
/*
- * Tries to drain stocked charges in other cpus. This function is asynchronous
- * and just put a work per cpu for draining localy on each cpu. Caller can
- * expects some charges will be back to res_counter later but cannot wait for
- * it.
+ * Drains all per-CPU charge caches for given root_mem resp. subtree
+ * of the hierarchy under it. sync flag says whether we should block
+ * until the work is done.
*/
-static void drain_all_stock_async(struct mem_cgroup *root_mem)
+static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
{
int cpu, curcpu;
- /*
- * If someone calls draining, avoid adding more kworker runs.
- */
- if (!mutex_trylock(&percpu_charge_mutex))
- return;
+
/* Notify other cpus that system-wide "drain" is running */
get_online_cpus();
/*
mem = stock->cached;
if (!mem || !stock->nr_pages)
continue;
- if (mem != root_mem) {
- if (!root_mem->use_hierarchy)
- continue;
- /* check whether "mem" is under tree of "root_mem" */
- if (!css_is_ancestor(&mem->css, &root_mem->css))
- continue;
- }
+ if (!mem_cgroup_same_or_subtree(root_mem, mem))
+ continue;
if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
if (cpu == curcpu)
drain_local_stock(&stock->work);
schedule_work_on(cpu, &stock->work);
}
}
+
+ if (!sync)
+ goto out;
+
+ for_each_online_cpu(cpu) {
+ struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+ if (mem_cgroup_same_or_subtree(root_mem, stock->cached) &&
+ test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
+ flush_work(&stock->work);
+ }
+out:
put_online_cpus();
- mutex_unlock(&percpu_charge_mutex);
- /* We don't wait for flush_work */
+}
+
+/*
+ * Tries to drain stocked charges in other cpus. This function is asynchronous
+ * and just put a work per cpu for draining localy on each cpu. Caller can
+ * expects some charges will be back to res_counter later but cannot wait for
+ * it.
+ */
+static void drain_all_stock_async(struct mem_cgroup *root_mem)
+{
+ drain_all_stock(root_mem, false);
}
/* This is a synchronous drain interface. */
-static void drain_all_stock_sync(void)
+static void drain_all_stock_sync(struct mem_cgroup *root_mem)
{
/* called when force_empty is called */
- mutex_lock(&percpu_charge_mutex);
- schedule_on_each_cpu(drain_local_stock);
- mutex_unlock(&percpu_charge_mutex);
+ drain_all_stock(root_mem, true);
}
/*
return 0;
if (PageCompound(page))
return 0;
- /*
- * Corner case handling. This is called from add_to_page_cache()
- * in usual. But some FS (shmem) precharges this page before calling it
- * and call add_to_page_cache() with GFP_NOWAIT.
- *
- * For GFP_NOWAIT case, the page may be pre-charged before calling
- * add_to_page_cache(). (See shmem.c) check it here and avoid to call
- * charge twice. (It works but has to pay a bit larger cost.)
- * And when the page is SwapCache, it should take swap information
- * into account. This is under lock_page() now.
- */
- if (!(gfp_mask & __GFP_WAIT)) {
- struct page_cgroup *pc;
-
- pc = lookup_page_cgroup(page);
- if (!pc)
- return 0;
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc)) {
- unlock_page_cgroup(pc);
- return 0;
- }
- unlock_page_cgroup(pc);
- }
if (unlikely(!mm))
mm = &init_mm;
cgroup_release_and_wakeup_rmdir(&mem->css);
}
-/*
- * 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_shmem_charge_fallback(struct page *page,
- struct mm_struct *mm,
- gfp_t gfp_mask)
-{
- struct mem_cgroup *mem;
- int ret;
-
- if (mem_cgroup_disabled())
- return 0;
-
- ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
- if (!ret)
- mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
-
- return ret;
-}
-
#ifdef CONFIG_DEBUG_VM
static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
{
goto out;
/* This is for making all *used* pages to be on LRU. */
lru_add_drain_all();
- drain_all_stock_sync();
+ drain_all_stock_sync(mem);
ret = 0;
mem_cgroup_start_move(mem);
for_each_node_state(node, N_HIGH_MEMORY) {
pgoff = pte_to_pgoff(ptent);
/* page is moved even if it's not RSS of this task(page-faulted). */
- if (!mapping_cap_swap_backed(mapping)) { /* normal file */
- page = find_get_page(mapping, pgoff);
- } else { /* shmem/tmpfs file. we should take account of swap too. */
- swp_entry_t ent;
- mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
+ page = find_get_page(mapping, pgoff);
+
+#ifdef CONFIG_SWAP
+ /* shmem/tmpfs may report page out on swap: account for that too. */
+ if (radix_tree_exceptional_entry(page)) {
+ swp_entry_t swap = radix_to_swp_entry(page);
if (do_swap_account)
- entry->val = ent.val;
+ *entry = swap;
+ page = find_get_page(&swapper_space, swap.val);
}
-
+#endif
return page;
}