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Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c139
1 files changed, 109 insertions, 30 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ec4dcf1b9562..28928ce9b07f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -292,6 +292,9 @@ struct mem_cgroup {
/* vmpressure notifications */
struct vmpressure vmpressure;
+ /* css_online() has been completed */
+ int initialized;
+
/*
* the counter to account for mem+swap usage.
*/
@@ -1099,10 +1102,21 @@ skip_node:
* skipping css reference should be safe.
*/
if (next_css) {
- if ((next_css == &root->css) ||
- ((next_css->flags & CSS_ONLINE) &&
- css_tryget_online(next_css)))
- return mem_cgroup_from_css(next_css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(next_css);
+
+ if (next_css == &root->css)
+ return memcg;
+
+ if (css_tryget_online(next_css)) {
+ /*
+ * Make sure the memcg is initialized:
+ * mem_cgroup_css_online() orders the the
+ * initialization against setting the flag.
+ */
+ if (smp_load_acquire(&memcg->initialized))
+ return memcg;
+ css_put(next_css);
+ }
prev_css = next_css;
goto skip_node;
@@ -2534,6 +2548,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
unsigned long long size;
int ret = 0;
+ if (mem_cgroup_is_root(memcg))
+ goto done;
retry:
if (consume_stock(memcg, nr_pages))
goto done;
@@ -2611,9 +2627,7 @@ nomem:
if (!(gfp_mask & __GFP_NOFAIL))
return -ENOMEM;
bypass:
- memcg = root_mem_cgroup;
- ret = -EINTR;
- goto retry;
+ return -EINTR;
done_restock:
if (batch > nr_pages)
@@ -2626,6 +2640,9 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
{
unsigned long bytes = nr_pages * PAGE_SIZE;
+ if (mem_cgroup_is_root(memcg))
+ return;
+
res_counter_uncharge(&memcg->res, bytes);
if (do_swap_account)
res_counter_uncharge(&memcg->memsw, bytes);
@@ -2640,6 +2657,9 @@ static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
{
unsigned long bytes = nr_pages * PAGE_SIZE;
+ if (mem_cgroup_is_root(memcg))
+ return;
+
res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
if (do_swap_account)
res_counter_uncharge_until(&memcg->memsw,
@@ -4093,6 +4113,46 @@ out:
return retval;
}
+static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ struct mem_cgroup *iter;
+ long val = 0;
+
+ /* Per-cpu values can be negative, use a signed accumulator */
+ for_each_mem_cgroup_tree(iter, memcg)
+ val += mem_cgroup_read_stat(iter, idx);
+
+ if (val < 0) /* race ? */
+ val = 0;
+ return val;
+}
+
+static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
+{
+ u64 val;
+
+ if (!mem_cgroup_is_root(memcg)) {
+ if (!swap)
+ return res_counter_read_u64(&memcg->res, RES_USAGE);
+ else
+ return res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ }
+
+ /*
+ * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
+ * as well as in MEM_CGROUP_STAT_RSS_HUGE.
+ */
+ val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
+
+ if (swap)
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
+
+ return val << PAGE_SHIFT;
+}
+
+
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
@@ -4102,8 +4162,12 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
switch (type) {
case _MEM:
+ if (name == RES_USAGE)
+ return mem_cgroup_usage(memcg, false);
return res_counter_read_u64(&memcg->res, name);
case _MEMSWAP:
+ if (name == RES_USAGE)
+ return mem_cgroup_usage(memcg, true);
return res_counter_read_u64(&memcg->memsw, name);
case _KMEM:
return res_counter_read_u64(&memcg->kmem, name);
@@ -4572,10 +4636,7 @@ static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
if (!t)
goto unlock;
- if (!swap)
- usage = res_counter_read_u64(&memcg->res, RES_USAGE);
- else
- usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ usage = mem_cgroup_usage(memcg, swap);
/*
* current_threshold points to threshold just below or equal to usage.
@@ -4673,10 +4734,10 @@ static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
if (type == _MEM) {
thresholds = &memcg->thresholds;
- usage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ usage = mem_cgroup_usage(memcg, false);
} else if (type == _MEMSWAP) {
thresholds = &memcg->memsw_thresholds;
- usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ usage = mem_cgroup_usage(memcg, true);
} else
BUG();
@@ -4762,10 +4823,10 @@ static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
if (type == _MEM) {
thresholds = &memcg->thresholds;
- usage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ usage = mem_cgroup_usage(memcg, false);
} else if (type == _MEMSWAP) {
thresholds = &memcg->memsw_thresholds;
- usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ usage = mem_cgroup_usage(memcg, true);
} else
BUG();
@@ -5502,6 +5563,7 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup *parent = mem_cgroup_from_css(css->parent);
+ int ret;
if (css->id > MEM_CGROUP_ID_MAX)
return -ENOSPC;
@@ -5525,9 +5587,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
* core guarantees its existence.
*/
} else {
- res_counter_init(&memcg->res, &root_mem_cgroup->res);
- res_counter_init(&memcg->memsw, &root_mem_cgroup->memsw);
- res_counter_init(&memcg->kmem, &root_mem_cgroup->kmem);
+ res_counter_init(&memcg->res, NULL);
+ res_counter_init(&memcg->memsw, NULL);
+ res_counter_init(&memcg->kmem, NULL);
/*
* Deeper hierachy with use_hierarchy == false doesn't make
* much sense so let cgroup subsystem know about this
@@ -5538,7 +5600,18 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
}
mutex_unlock(&memcg_create_mutex);
- return memcg_init_kmem(memcg, &memory_cgrp_subsys);
+ ret = memcg_init_kmem(memcg, &memory_cgrp_subsys);
+ if (ret)
+ return ret;
+
+ /*
+ * Make sure the memcg is initialized: mem_cgroup_iter()
+ * orders reading memcg->initialized against its callers
+ * reading the memcg members.
+ */
+ smp_store_release(&memcg->initialized, 1);
+
+ return 0;
}
/*
@@ -5969,8 +6042,9 @@ static void __mem_cgroup_clear_mc(void)
/* we must fixup refcnts and charges */
if (mc.moved_swap) {
/* uncharge swap account from the old cgroup */
- res_counter_uncharge(&mc.from->memsw,
- PAGE_SIZE * mc.moved_swap);
+ if (!mem_cgroup_is_root(mc.from))
+ res_counter_uncharge(&mc.from->memsw,
+ PAGE_SIZE * mc.moved_swap);
for (i = 0; i < mc.moved_swap; i++)
css_put(&mc.from->css);
@@ -5979,8 +6053,9 @@ static void __mem_cgroup_clear_mc(void)
* we charged both to->res and to->memsw, so we should
* uncharge to->res.
*/
- res_counter_uncharge(&mc.to->res,
- PAGE_SIZE * mc.moved_swap);
+ if (!mem_cgroup_is_root(mc.to))
+ res_counter_uncharge(&mc.to->res,
+ PAGE_SIZE * mc.moved_swap);
/* we've already done css_get(mc.to) */
mc.moved_swap = 0;
}
@@ -6345,7 +6420,8 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry)
rcu_read_lock();
memcg = mem_cgroup_lookup(id);
if (memcg) {
- res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+ if (!mem_cgroup_is_root(memcg))
+ res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
mem_cgroup_swap_statistics(memcg, false);
css_put(&memcg->css);
}
@@ -6509,12 +6585,15 @@ static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
{
unsigned long flags;
- if (nr_mem)
- res_counter_uncharge(&memcg->res, nr_mem * PAGE_SIZE);
- if (nr_memsw)
- res_counter_uncharge(&memcg->memsw, nr_memsw * PAGE_SIZE);
-
- memcg_oom_recover(memcg);
+ if (!mem_cgroup_is_root(memcg)) {
+ if (nr_mem)
+ res_counter_uncharge(&memcg->res,
+ nr_mem * PAGE_SIZE);
+ if (nr_memsw)
+ res_counter_uncharge(&memcg->memsw,
+ nr_memsw * PAGE_SIZE);
+ memcg_oom_recover(memcg);
+ }
local_irq_save(flags);
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-08 01:53:42 +0300