* the counter to account for memory usage
*/
struct res_counter res;
- /*
- * the counter to account for mem+swap usage.
- */
- struct res_counter memsw;
+
+ union {
+ /*
+ * the counter to account for mem+swap usage.
+ */
+ struct res_counter memsw;
+
+ /*
+ * rcu_freeing is used only when freeing struct mem_cgroup,
+ * so put it into a union to avoid wasting more memory.
+ * It must be disjoint from the css field. It could be
+ * in a union with the res field, but res plays a much
+ * larger part in mem_cgroup life than memsw, and might
+ * be of interest, even at time of free, when debugging.
+ * So share rcu_head with the less interesting memsw.
+ */
+ struct rcu_head rcu_freeing;
+ /*
+ * But when using vfree(), that cannot be done at
+ * interrupt time, so we must then queue the work.
+ */
+ struct work_struct work_freeing;
+ };
+
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
void sock_update_memcg(struct sock *sk)
{
- if (static_branch(&memcg_socket_limit_enabled)) {
+ if (mem_cgroup_sockets_enabled) {
struct mem_cgroup *memcg;
BUG_ON(!sk->sk_prot->proto_cgroup);
void sock_release_memcg(struct sock *sk)
{
- if (static_branch(&memcg_socket_limit_enabled) && sk->sk_cgrp) {
+ if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
struct mem_cgroup *memcg;
WARN_ON(!sk->sk_cgrp->memcg);
memcg = sk->sk_cgrp->memcg;
/* threshold event is triggered in finer grain than soft limit */
if (unlikely(mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_THRESH))) {
- bool do_softlimit, do_numainfo;
+ bool do_softlimit;
+ bool do_numainfo __maybe_unused;
do_softlimit = mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_SOFTLIMIT);
pc = lookup_page_cgroup(page);
memcg = pc->mem_cgroup;
+
+ /*
+ * Surreptitiously switch any uncharged page to root:
+ * an uncharged page off lru does nothing to secure
+ * its former mem_cgroup from sudden removal.
+ *
+ * Our caller holds lru_lock, and PageCgroupUsed is updated
+ * under page_cgroup lock: between them, they make all uses
+ * of pc->mem_cgroup safe.
+ */
+ if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup)
+ pc->mem_cgroup = memcg = root_mem_cgroup;
+
mz = page_cgroup_zoneinfo(memcg, page);
/* compound_order() is stabilized through lru_lock */
MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
struct page *page,
unsigned int nr_pages,
struct page_cgroup *pc,
- enum charge_type ctype)
+ enum charge_type ctype,
+ bool lrucare)
{
+ struct zone *uninitialized_var(zone);
+ bool was_on_lru = false;
+
lock_page_cgroup(pc);
if (unlikely(PageCgroupUsed(pc))) {
unlock_page_cgroup(pc);
* we don't need page_cgroup_lock about tail pages, becase they are not
* accessed by any other context at this point.
*/
+
+ /*
+ * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
+ * may already be on some other mem_cgroup's LRU. Take care of it.
+ */
+ if (lrucare) {
+ zone = page_zone(page);
+ spin_lock_irq(&zone->lru_lock);
+ if (PageLRU(page)) {
+ ClearPageLRU(page);
+ del_page_from_lru_list(zone, page, page_lru(page));
+ was_on_lru = true;
+ }
+ }
+
pc->mem_cgroup = memcg;
/*
* We access a page_cgroup asynchronously without lock_page_cgroup().
break;
}
+ if (lrucare) {
+ if (was_on_lru) {
+ VM_BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+ add_page_to_lru_list(zone, page, page_lru(page));
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
unlock_page_cgroup(pc);
- WARN_ON_ONCE(PageLRU(page));
+
/*
* "charge_statistics" updated event counter. Then, check it.
* Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
if (ret == -ENOMEM)
return ret;
- __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
+ __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype, false);
return 0;
}
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
enum charge_type ctype);
-static void
-__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
- enum charge_type ctype)
-{
- struct page_cgroup *pc = lookup_page_cgroup(page);
- struct zone *zone = page_zone(page);
- unsigned long flags;
- bool removed = false;
-
- /*
- * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
- * is already on LRU. It means the page may on some other page_cgroup's
- * LRU. Take care of it.
- */
- spin_lock_irqsave(&zone->lru_lock, flags);
- if (PageLRU(page)) {
- del_page_from_lru_list(zone, page, page_lru(page));
- ClearPageLRU(page);
- removed = true;
- }
- __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
- if (removed) {
- add_page_to_lru_list(zone, page, page_lru(page));
- SetPageLRU(page);
- }
- spin_unlock_irqrestore(&zone->lru_lock, flags);
- return;
-}
-
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask)
{
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
enum charge_type ctype)
{
+ struct page_cgroup *pc;
+
if (mem_cgroup_disabled())
return;
if (!memcg)
return;
cgroup_exclude_rmdir(&memcg->css);
- __mem_cgroup_commit_charge_lrucare(page, memcg, ctype);
+ pc = lookup_page_cgroup(page);
+ __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype, true);
/*
* Now swap is on-memory. This means this page may be
* counted both as mem and swap....double count.
batch->memcg = NULL;
}
-/*
- * A function for resetting pc->mem_cgroup for newly allocated pages.
- * This function should be called if the newpage will be added to LRU
- * before start accounting.
- */
-void mem_cgroup_reset_owner(struct page *newpage)
-{
- struct page_cgroup *pc;
-
- if (mem_cgroup_disabled())
- return;
-
- pc = lookup_page_cgroup(newpage);
- VM_BUG_ON(PageCgroupUsed(pc));
- pc->mem_cgroup = root_mem_cgroup;
-}
-
#ifdef CONFIG_SWAP
/*
* called after __delete_from_swap_cache() and drop "page" account.
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
else
ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
- __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
+ __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype, false);
return ret;
}
* the newpage may be on LRU(or pagevec for LRU) already. We lock
* LRU while we overwrite pc->mem_cgroup.
*/
- __mem_cgroup_commit_charge_lrucare(newpage, memcg, type);
+ __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
}
#ifdef CONFIG_DEBUG_VM
*/
BUG_ON(!thresholds);
+ if (!thresholds->primary)
+ goto unlock;
+
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
/* Check if a threshold crossed before removing */
/* To be sure that nobody uses thresholds */
synchronize_rcu();
-
+unlock:
mutex_unlock(&memcg->thresholds_lock);
}
return NULL;
}
+/*
+ * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
+ * but in process context. The work_freeing structure is overlaid
+ * on the rcu_freeing structure, which itself is overlaid on memsw.
+ */
+static void vfree_work(struct work_struct *work)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(work, struct mem_cgroup, work_freeing);
+ vfree(memcg);
+}
+static void vfree_rcu(struct rcu_head *rcu_head)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
+ INIT_WORK(&memcg->work_freeing, vfree_work);
+ schedule_work(&memcg->work_freeing);
+}
+
/*
* At destroying mem_cgroup, references from swap_cgroup can remain.
* (scanning all at force_empty is too costly...)
free_percpu(memcg->stat);
if (sizeof(struct mem_cgroup) < PAGE_SIZE)
- kfree(memcg);
+ kfree_rcu(memcg, rcu_freeing);
else
- vfree(memcg);
+ call_rcu(&memcg->rcu_freeing, vfree_rcu);
}
static void mem_cgroup_get(struct mem_cgroup *memcg)
projects / ~andy / linux / blobdiff