u64 threshold;
};
+/* For threshold */
struct mem_cgroup_threshold_ary {
/* An array index points to threshold just below usage. */
- atomic_t current_threshold;
+ int current_threshold;
/* Size of entries[] */
unsigned int size;
/* Array of thresholds */
struct mem_cgroup_threshold entries[0];
};
+struct mem_cgroup_thresholds {
+ /* Primary thresholds array */
+ struct mem_cgroup_threshold_ary *primary;
+ /*
+ * Spare threshold array.
+ * This is needed to make mem_cgroup_unregister_event() "never fail".
+ * It must be able to store at least primary->size - 1 entries.
+ */
+ struct mem_cgroup_threshold_ary *spare;
+};
+
+/* for OOM */
+struct mem_cgroup_eventfd_list {
+ struct list_head list;
+ struct eventfd_ctx *eventfd;
+};
+
static void mem_cgroup_threshold(struct mem_cgroup *mem);
+static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
/*
* The memory controller data structure. The memory controller controls both
atomic_t refcnt;
unsigned int swappiness;
+ /* OOM-Killer disable */
+ int oom_kill_disable;
/* set when res.limit == memsw.limit */
bool memsw_is_minimum;
struct mutex thresholds_lock;
/* thresholds for memory usage. RCU-protected */
- struct mem_cgroup_threshold_ary *thresholds;
+ struct mem_cgroup_thresholds thresholds;
/* thresholds for mem+swap usage. RCU-protected */
- struct mem_cgroup_threshold_ary *memsw_thresholds;
+ struct mem_cgroup_thresholds memsw_thresholds;
+
+ /* For oom notifier event fd */
+ struct list_head oom_notify;
/*
* Should we move charges of a task when a task is moved into this
* mem_cgroup ? And what type of charges should we move ?
*/
unsigned long move_charge_at_immigrate;
-
/*
* percpu counter.
*/
*/
enum move_type {
MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
+ MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
NR_MOVE_TYPE,
};
.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
};
+static bool move_anon(void)
+{
+ return test_bit(MOVE_CHARGE_TYPE_ANON,
+ &mc.to->move_charge_at_immigrate);
+}
+
+static bool move_file(void)
+{
+ return test_bit(MOVE_CHARGE_TYPE_FILE,
+ &mc.to->move_charge_at_immigrate);
+}
+
/*
* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
* limit reclaim to prevent infinite loops, if they ever occur.
/* for encoding cft->private value on file */
#define _MEM (0)
#define _MEMSWAP (1)
+#define _OOM_TYPE (2)
#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)
+/* Used for OOM nofiier */
+#define OOM_CONTROL (0)
/*
* Reclaim flags for mem_cgroup_hierarchical_reclaim
static DEFINE_MUTEX(memcg_oom_mutex);
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
+struct oom_wait_info {
+ struct mem_cgroup *mem;
+ wait_queue_t wait;
+};
+
+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 oom_wait_info *oom_wait_info;
+
+ oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+
+ 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))
+ return 0;
+
+wakeup:
+ return autoremove_wake_function(wait, mode, sync, arg);
+}
+
+static void memcg_wakeup_oom(struct mem_cgroup *mem)
+{
+ /* for filtering, pass "mem" as argument. */
+ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
+}
+
+static void memcg_oom_recover(struct mem_cgroup *mem)
+{
+ if (mem->oom_kill_disable && atomic_read(&mem->oom_lock))
+ memcg_wakeup_oom(mem);
+}
+
/*
* try to call OOM killer. returns false if we should exit memory-reclaim loop.
*/
bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
{
- DEFINE_WAIT(wait);
- bool locked;
+ struct oom_wait_info owait;
+ bool locked, need_to_kill;
+ owait.mem = mem;
+ owait.wait.flags = 0;
+ owait.wait.func = memcg_oom_wake_function;
+ owait.wait.private = current;
+ INIT_LIST_HEAD(&owait.wait.task_list);
+ need_to_kill = true;
/* At first, try to OOM lock hierarchy under mem.*/
mutex_lock(&memcg_oom_mutex);
locked = mem_cgroup_oom_lock(mem);
* accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
* under OOM is always welcomed, use TASK_KILLABLE here.
*/
- if (!locked)
- prepare_to_wait(&memcg_oom_waitq, &wait, TASK_KILLABLE);
+ prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
+ if (!locked || mem->oom_kill_disable)
+ need_to_kill = false;
+ if (locked)
+ mem_cgroup_oom_notify(mem);
mutex_unlock(&memcg_oom_mutex);
- if (locked)
+ if (need_to_kill) {
+ finish_wait(&memcg_oom_waitq, &owait.wait);
mem_cgroup_out_of_memory(mem, mask);
- else {
+ } else {
schedule();
- finish_wait(&memcg_oom_waitq, &wait);
+ finish_wait(&memcg_oom_waitq, &owait.wait);
}
mutex_lock(&memcg_oom_mutex);
mem_cgroup_oom_unlock(mem);
- /*
- * Here, we use global waitq .....more fine grained waitq ?
- * Assume following hierarchy.
- * A/
- * 01
- * 02
- * assume OOM happens both in A and 01 at the same time. Tthey are
- * mutually exclusive by lock. (kill in 01 helps A.)
- * When we use per memcg waitq, we have to wake up waiters on A and 02
- * in addtion to waiters on 01. We use global waitq for avoiding mess.
- * It will not be a big problem.
- * (And a task may be moved to other groups while it's waiting for OOM.)
- */
- wake_up_all(&memcg_oom_waitq);
+ memcg_wakeup_oom(mem);
mutex_unlock(&memcg_oom_mutex);
if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
/*
* Cache charges(val) which is from res_counter, to local per_cpu area.
- * This will be consumed by consumt_stock() function, later.
+ * This will be consumed by consume_stock() function, later.
*/
static void refill_stock(struct mem_cgroup *mem, int val)
{
* There is a small race that "from" or "to" can be
* freed by rmdir, so we use css_tryget().
*/
- rcu_read_lock();
from = mc.from;
to = mc.to;
if (from && css_tryget(&from->css)) {
do_continue = (to == mem_over_limit);
css_put(&to->css);
}
- rcu_read_unlock();
if (do_continue) {
DEFINE_WAIT(wait);
prepare_to_wait(&mc.waitq, &wait,
/* If swapout, usage of swap doesn't decrease */
if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
uncharge_memsw = false;
- /*
- * do_batch > 0 when unmapping pages or inode invalidate/truncate.
- * In those cases, all pages freed continously can be expected to be in
- * the same cgroup and we have chance to coalesce uncharges.
- * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
- * because we want to do uncharge as soon as possible.
- */
- if (!current->memcg_batch.do_batch || test_thread_flag(TIF_MEMDIE))
- goto direct_uncharge;
batch = ¤t->memcg_batch;
/*
if (!batch->memcg)
batch->memcg = mem;
/*
+ * do_batch > 0 when unmapping pages or inode invalidate/truncate.
+ * In those cases, all pages freed continously can be expected to be in
+ * the same cgroup and we have chance to coalesce uncharges.
+ * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
+ * because we want to do uncharge as soon as possible.
+ */
+
+ if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
+ goto direct_uncharge;
+
+ /*
* In typical case, batch->memcg == mem. This means we can
* merge a series of uncharges to an uncharge of res_counter.
* If not, we uncharge res_counter ony by one.
res_counter_uncharge(&mem->res, PAGE_SIZE);
if (uncharge_memsw)
res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+ if (unlikely(batch->memcg != mem))
+ memcg_oom_recover(mem);
return;
}
switch (ctype) {
case MEM_CGROUP_CHARGE_TYPE_MAPPED:
case MEM_CGROUP_CHARGE_TYPE_DROP:
- if (page_mapped(page))
+ /* See mem_cgroup_prepare_migration() */
+ if (page_mapped(page) || PageCgroupMigration(pc))
goto unlock_out;
break;
case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
res_counter_uncharge(&batch->memcg->res, batch->bytes);
if (batch->memsw_bytes)
res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
+ memcg_oom_recover(batch->memcg);
/* forget this pointer (for sanity check) */
batch->memcg = NULL;
}
* Before starting migration, account PAGE_SIZE to mem_cgroup that the old
* page belongs to.
*/
-int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
+int mem_cgroup_prepare_migration(struct page *page,
+ struct page *newpage, struct mem_cgroup **ptr)
{
struct page_cgroup *pc;
struct mem_cgroup *mem = NULL;
+ enum charge_type ctype;
int ret = 0;
if (mem_cgroup_disabled())
if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
css_get(&mem->css);
+ /*
+ * At migrating an anonymous page, its mapcount goes down
+ * to 0 and uncharge() will be called. But, even if it's fully
+ * unmapped, migration may fail and this page has to be
+ * charged again. We set MIGRATION flag here and delay uncharge
+ * until end_migration() is called
+ *
+ * Corner Case Thinking
+ * A)
+ * When the old page was mapped as Anon and it's unmap-and-freed
+ * while migration was ongoing.
+ * If unmap finds the old page, uncharge() of it will be delayed
+ * until end_migration(). If unmap finds a new page, it's
+ * uncharged when it make mapcount to be 1->0. If unmap code
+ * finds swap_migration_entry, the new page will not be mapped
+ * and end_migration() will find it(mapcount==0).
+ *
+ * B)
+ * When the old page was mapped but migraion fails, the kernel
+ * remaps it. A charge for it is kept by MIGRATION flag even
+ * if mapcount goes down to 0. We can do remap successfully
+ * without charging it again.
+ *
+ * C)
+ * The "old" page is under lock_page() until the end of
+ * migration, so, the old page itself will not be swapped-out.
+ * If the new page is swapped out before end_migraton, our
+ * hook to usual swap-out path will catch the event.
+ */
+ if (PageAnon(page))
+ SetPageCgroupMigration(pc);
}
unlock_page_cgroup(pc);
+ /*
+ * If the page is not charged at this point,
+ * we return here.
+ */
+ if (!mem)
+ return 0;
- if (mem) {
- ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
- css_put(&mem->css);
- }
*ptr = mem;
+ ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false);
+ css_put(&mem->css);/* drop extra refcnt */
+ if (ret || *ptr == NULL) {
+ if (PageAnon(page)) {
+ lock_page_cgroup(pc);
+ ClearPageCgroupMigration(pc);
+ unlock_page_cgroup(pc);
+ /*
+ * The old page may be fully unmapped while we kept it.
+ */
+ mem_cgroup_uncharge_page(page);
+ }
+ return -ENOMEM;
+ }
+ /*
+ * We charge new page before it's used/mapped. So, even if unlock_page()
+ * is called before end_migration, we can catch all events on this new
+ * page. In the case new page is migrated but not remapped, new page's
+ * mapcount will be finally 0 and we call uncharge in end_migration().
+ */
+ pc = lookup_page_cgroup(newpage);
+ if (PageAnon(page))
+ ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
+ else if (page_is_file_cache(page))
+ ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+ else
+ ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+ __mem_cgroup_commit_charge(mem, pc, ctype);
return ret;
}
/* remove redundant charge if migration failed*/
void mem_cgroup_end_migration(struct mem_cgroup *mem,
- struct page *oldpage, struct page *newpage)
+ struct page *oldpage, struct page *newpage)
{
- struct page *target, *unused;
+ struct page *used, *unused;
struct page_cgroup *pc;
- enum charge_type ctype;
if (!mem)
return;
+ /* blocks rmdir() */
cgroup_exclude_rmdir(&mem->css);
/* at migration success, oldpage->mapping is NULL. */
if (oldpage->mapping) {
- target = oldpage;
- unused = NULL;
+ used = oldpage;
+ unused = newpage;
} else {
- target = newpage;
+ used = newpage;
unused = oldpage;
}
-
- if (PageAnon(target))
- ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
- else if (page_is_file_cache(target))
- ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
- else
- ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-
- /* unused page is not on radix-tree now. */
- if (unused)
- __mem_cgroup_uncharge_common(unused, ctype);
-
- pc = lookup_page_cgroup(target);
/*
- * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
- * So, double-counting is effectively avoided.
+ * We disallowed uncharge of pages under migration because mapcount
+ * of the page goes down to zero, temporarly.
+ * Clear the flag and check the page should be charged.
*/
- __mem_cgroup_commit_charge(mem, pc, ctype);
+ pc = lookup_page_cgroup(oldpage);
+ lock_page_cgroup(pc);
+ ClearPageCgroupMigration(pc);
+ unlock_page_cgroup(pc);
+ if (unused != oldpage)
+ pc = lookup_page_cgroup(unused);
+ __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
+
+ pc = lookup_page_cgroup(used);
/*
- * Both of oldpage and newpage are still under lock_page().
- * Then, we don't have to care about race in radix-tree.
- * But we have to be careful that this page is unmapped or not.
- *
- * There is a case for !page_mapped(). At the start of
- * migration, oldpage was mapped. But now, it's zapped.
- * But we know *target* page is not freed/reused under us.
- * mem_cgroup_uncharge_page() does all necessary checks.
+ * If a page is a file cache, radix-tree replacement is very atomic
+ * and we can skip this check. When it was an Anon page, its mapcount
+ * goes down to 0. But because we added MIGRATION flage, it's not
+ * uncharged yet. There are several case but page->mapcount check
+ * and USED bit check in mem_cgroup_uncharge_page() will do enough
+ * check. (see prepare_charge() also)
*/
- if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
- mem_cgroup_uncharge_page(target);
+ if (PageAnon(used))
+ mem_cgroup_uncharge_page(used);
/*
- * At migration, we may charge account against cgroup which has no tasks
+ * At migration, we may charge account against cgroup which has no
+ * tasks.
* So, rmdir()->pre_destroy() can be called while we do this charge.
* In that case, we need to call pre_destroy() again. check it here.
*/
unsigned long long val)
{
int retry_count;
- u64 memswlimit;
+ u64 memswlimit, memlimit;
int ret = 0;
int children = mem_cgroup_count_children(memcg);
u64 curusage, oldusage;
+ int enlarge;
/*
* For keeping hierarchical_reclaim simple, how long we should retry
oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ enlarge = 0;
while (retry_count) {
if (signal_pending(current)) {
ret = -EINTR;
mutex_unlock(&set_limit_mutex);
break;
}
+
+ memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ if (memlimit < val)
+ enlarge = 1;
+
ret = res_counter_set_limit(&memcg->res, val);
if (!ret) {
if (memswlimit == val)
else
oldusage = curusage;
}
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
return ret;
}
unsigned long long val)
{
int retry_count;
- u64 memlimit, oldusage, curusage;
+ u64 memlimit, memswlimit, oldusage, curusage;
int children = mem_cgroup_count_children(memcg);
int ret = -EBUSY;
+ int enlarge = 0;
/* see mem_cgroup_resize_res_limit */
retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
mutex_unlock(&set_limit_mutex);
break;
}
+ memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ if (memswlimit < val)
+ enlarge = 1;
ret = res_counter_set_limit(&memcg->memsw, val);
if (!ret) {
if (memlimit == val)
else
oldusage = curusage;
}
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
return ret;
}
if (ret)
break;
}
+ memcg_oom_recover(mem);
/* it seems parent cgroup doesn't have enough mem */
if (ret == -ENOMEM)
goto try_to_free;
rcu_read_lock();
if (!swap)
- t = rcu_dereference(memcg->thresholds);
+ t = rcu_dereference(memcg->thresholds.primary);
else
- t = rcu_dereference(memcg->memsw_thresholds);
+ t = rcu_dereference(memcg->memsw_thresholds.primary);
if (!t)
goto unlock;
* If it's not true, a threshold was crossed after last
* call of __mem_cgroup_threshold().
*/
- i = atomic_read(&t->current_threshold);
+ i = t->current_threshold;
/*
* Iterate backward over array of thresholds starting from
eventfd_signal(t->entries[i].eventfd, 1);
/* Update current_threshold */
- atomic_set(&t->current_threshold, i - 1);
+ t->current_threshold = i - 1;
unlock:
rcu_read_unlock();
}
return _a->threshold - _b->threshold;
}
-static int mem_cgroup_register_event(struct cgroup *cgrp, struct cftype *cft,
- struct eventfd_ctx *eventfd, const char *args)
+static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem, void *data)
+{
+ struct mem_cgroup_eventfd_list *ev;
+
+ list_for_each_entry(ev, &mem->oom_notify, list)
+ eventfd_signal(ev->eventfd, 1);
+ return 0;
+}
+
+static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
+{
+ mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_notify_cb);
+}
+
+static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
- struct mem_cgroup_threshold_ary *thresholds, *thresholds_new;
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
int type = MEMFILE_TYPE(cft->private);
u64 threshold, usage;
- int size;
- int i, ret;
+ int i, size, ret;
ret = res_counter_memparse_write_strategy(args, &threshold);
if (ret)
return ret;
mutex_lock(&memcg->thresholds_lock);
+
if (type == _MEM)
- thresholds = memcg->thresholds;
+ thresholds = &memcg->thresholds;
else if (type == _MEMSWAP)
- thresholds = memcg->memsw_thresholds;
+ thresholds = &memcg->memsw_thresholds;
else
BUG();
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
/* Check if a threshold crossed before adding a new one */
- if (thresholds)
+ if (thresholds->primary)
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
- if (thresholds)
- size = thresholds->size + 1;
- else
- size = 1;
+ size = thresholds->primary ? thresholds->primary->size + 1 : 1;
/* Allocate memory for new array of thresholds */
- thresholds_new = kmalloc(sizeof(*thresholds_new) +
- size * sizeof(struct mem_cgroup_threshold),
+ new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
GFP_KERNEL);
- if (!thresholds_new) {
+ if (!new) {
ret = -ENOMEM;
goto unlock;
}
- thresholds_new->size = size;
+ new->size = size;
/* Copy thresholds (if any) to new array */
- if (thresholds)
- memcpy(thresholds_new->entries, thresholds->entries,
- thresholds->size *
+ if (thresholds->primary) {
+ memcpy(new->entries, thresholds->primary->entries, (size - 1) *
sizeof(struct mem_cgroup_threshold));
+ }
+
/* Add new threshold */
- thresholds_new->entries[size - 1].eventfd = eventfd;
- thresholds_new->entries[size - 1].threshold = threshold;
+ new->entries[size - 1].eventfd = eventfd;
+ new->entries[size - 1].threshold = threshold;
/* Sort thresholds. Registering of new threshold isn't time-critical */
- sort(thresholds_new->entries, size,
- sizeof(struct mem_cgroup_threshold),
+ sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
compare_thresholds, NULL);
/* Find current threshold */
- atomic_set(&thresholds_new->current_threshold, -1);
+ new->current_threshold = -1;
for (i = 0; i < size; i++) {
- if (thresholds_new->entries[i].threshold < usage) {
+ if (new->entries[i].threshold < usage) {
/*
- * thresholds_new->current_threshold will not be used
- * until rcu_assign_pointer(), so it's safe to increment
+ * new->current_threshold will not be used until
+ * rcu_assign_pointer(), so it's safe to increment
* it here.
*/
- atomic_inc(&thresholds_new->current_threshold);
+ ++new->current_threshold;
}
}
- if (type == _MEM)
- rcu_assign_pointer(memcg->thresholds, thresholds_new);
- else
- rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new);
+ /* Free old spare buffer and save old primary buffer as spare */
+ kfree(thresholds->spare);
+ thresholds->spare = thresholds->primary;
- /* To be sure that nobody uses thresholds before freeing it */
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
synchronize_rcu();
- kfree(thresholds);
unlock:
mutex_unlock(&memcg->thresholds_lock);
return ret;
}
-static int mem_cgroup_unregister_event(struct cgroup *cgrp, struct cftype *cft,
- struct eventfd_ctx *eventfd)
+static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
- struct mem_cgroup_threshold_ary *thresholds, *thresholds_new;
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
int type = MEMFILE_TYPE(cft->private);
u64 usage;
- int size = 0;
- int i, j, ret;
+ int i, j, size;
mutex_lock(&memcg->thresholds_lock);
if (type == _MEM)
- thresholds = memcg->thresholds;
+ thresholds = &memcg->thresholds;
else if (type == _MEMSWAP)
- thresholds = memcg->memsw_thresholds;
+ thresholds = &memcg->memsw_thresholds;
else
BUG();
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
/* Calculate new number of threshold */
- for (i = 0; i < thresholds->size; i++) {
- if (thresholds->entries[i].eventfd != eventfd)
+ size = 0;
+ for (i = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd != eventfd)
size++;
}
+ new = thresholds->spare;
+
/* Set thresholds array to NULL if we don't have thresholds */
if (!size) {
- thresholds_new = NULL;
- goto assign;
+ kfree(new);
+ new = NULL;
+ goto swap_buffers;
}
- /* Allocate memory for new array of thresholds */
- thresholds_new = kmalloc(sizeof(*thresholds_new) +
- size * sizeof(struct mem_cgroup_threshold),
- GFP_KERNEL);
- if (!thresholds_new) {
- ret = -ENOMEM;
- goto unlock;
- }
- thresholds_new->size = size;
+ new->size = size;
/* Copy thresholds and find current threshold */
- atomic_set(&thresholds_new->current_threshold, -1);
- for (i = 0, j = 0; i < thresholds->size; i++) {
- if (thresholds->entries[i].eventfd == eventfd)
+ new->current_threshold = -1;
+ for (i = 0, j = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd == eventfd)
continue;
- thresholds_new->entries[j] = thresholds->entries[i];
- if (thresholds_new->entries[j].threshold < usage) {
+ new->entries[j] = thresholds->primary->entries[i];
+ if (new->entries[j].threshold < usage) {
/*
- * thresholds_new->current_threshold will not be used
+ * new->current_threshold will not be used
* until rcu_assign_pointer(), so it's safe to increment
* it here.
*/
- atomic_inc(&thresholds_new->current_threshold);
+ ++new->current_threshold;
}
j++;
}
-assign:
- if (type == _MEM)
- rcu_assign_pointer(memcg->thresholds, thresholds_new);
- else
- rcu_assign_pointer(memcg->memsw_thresholds, thresholds_new);
+swap_buffers:
+ /* Swap primary and spare array */
+ thresholds->spare = thresholds->primary;
+ rcu_assign_pointer(thresholds->primary, new);
- /* To be sure that nobody uses thresholds before freeing it */
+ /* To be sure that nobody uses thresholds */
synchronize_rcu();
- kfree(thresholds);
-unlock:
mutex_unlock(&memcg->thresholds_lock);
+}
- return ret;
+static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_eventfd_list *event;
+ int type = MEMFILE_TYPE(cft->private);
+
+ BUG_ON(type != _OOM_TYPE);
+ event = kmalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ mutex_lock(&memcg_oom_mutex);
+
+ event->eventfd = eventfd;
+ list_add(&event->list, &memcg->oom_notify);
+
+ /* already in OOM ? */
+ if (atomic_read(&memcg->oom_lock))
+ eventfd_signal(eventfd, 1);
+ mutex_unlock(&memcg_oom_mutex);
+
+ return 0;
+}
+
+static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_eventfd_list *ev, *tmp;
+ int type = MEMFILE_TYPE(cft->private);
+
+ BUG_ON(type != _OOM_TYPE);
+
+ mutex_lock(&memcg_oom_mutex);
+
+ list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
+ if (ev->eventfd == eventfd) {
+ list_del(&ev->list);
+ kfree(ev);
+ }
+ }
+
+ mutex_unlock(&memcg_oom_mutex);
+}
+
+static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
+ struct cftype *cft, struct cgroup_map_cb *cb)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+
+ cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
+
+ if (atomic_read(&mem->oom_lock))
+ cb->fill(cb, "under_oom", 1);
+ else
+ cb->fill(cb, "under_oom", 0);
+ return 0;
+}
+
+/*
+ */
+static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup *parent;
+
+ /* cannot set to root cgroup and only 0 and 1 are allowed */
+ if (!cgrp->parent || !((val == 0) || (val == 1)))
+ return -EINVAL;
+
+ parent = mem_cgroup_from_cont(cgrp->parent);
+
+ cgroup_lock();
+ /* oom-kill-disable is a flag for subhierarchy. */
+ if ((parent->use_hierarchy) ||
+ (mem->use_hierarchy && !list_empty(&cgrp->children))) {
+ cgroup_unlock();
+ return -EINVAL;
+ }
+ mem->oom_kill_disable = val;
+ cgroup_unlock();
+ return 0;
}
static struct cftype mem_cgroup_files[] = {
.name = "usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
.read_u64 = mem_cgroup_read,
- .register_event = mem_cgroup_register_event,
- .unregister_event = mem_cgroup_unregister_event,
+ .register_event = mem_cgroup_usage_register_event,
+ .unregister_event = mem_cgroup_usage_unregister_event,
},
{
.name = "max_usage_in_bytes",
.read_u64 = mem_cgroup_move_charge_read,
.write_u64 = mem_cgroup_move_charge_write,
},
+ {
+ .name = "oom_control",
+ .read_map = mem_cgroup_oom_control_read,
+ .write_u64 = mem_cgroup_oom_control_write,
+ .register_event = mem_cgroup_oom_register_event,
+ .unregister_event = mem_cgroup_oom_unregister_event,
+ .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
+ },
};
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
.name = "memsw.usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
.read_u64 = mem_cgroup_read,
- .register_event = mem_cgroup_register_event,
- .unregister_event = mem_cgroup_unregister_event,
+ .register_event = mem_cgroup_usage_register_event,
+ .unregister_event = mem_cgroup_usage_unregister_event,
},
{
.name = "memsw.max_usage_in_bytes",
} else {
parent = mem_cgroup_from_cont(cont->parent);
mem->use_hierarchy = parent->use_hierarchy;
+ mem->oom_kill_disable = parent->oom_kill_disable;
}
if (parent && parent->use_hierarchy) {
}
mem->last_scanned_child = 0;
spin_lock_init(&mem->reclaim_param_lock);
+ INIT_LIST_HEAD(&mem->oom_notify);
if (parent)
mem->swappiness = get_swappiness(parent);
MC_TARGET_SWAP,
};
+static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent)
+{
+ struct page *page = vm_normal_page(vma, addr, ptent);
+
+ if (!page || !page_mapped(page))
+ return NULL;
+ if (PageAnon(page)) {
+ /* we don't move shared anon */
+ if (!move_anon() || page_mapcount(page) > 2)
+ return NULL;
+ } else if (!move_file())
+ /* we ignore mapcount for file pages */
+ return NULL;
+ if (!get_page_unless_zero(page))
+ return NULL;
+
+ return page;
+}
+
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ int usage_count;
+ struct page *page = NULL;
+ swp_entry_t ent = pte_to_swp_entry(ptent);
+
+ if (!move_anon() || non_swap_entry(ent))
+ return NULL;
+ usage_count = mem_cgroup_count_swap_user(ent, &page);
+ if (usage_count > 1) { /* we don't move shared anon */
+ if (page)
+ put_page(page);
+ return NULL;
+ }
+ if (do_swap_account)
+ entry->val = ent.val;
+
+ return page;
+}
+
+static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ struct page *page = NULL;
+ struct inode *inode;
+ struct address_space *mapping;
+ pgoff_t pgoff;
+
+ if (!vma->vm_file) /* anonymous vma */
+ return NULL;
+ if (!move_file())
+ return NULL;
+
+ inode = vma->vm_file->f_path.dentry->d_inode;
+ mapping = vma->vm_file->f_mapping;
+ if (pte_none(ptent))
+ pgoff = linear_page_index(vma, addr);
+ else /* pte_file(ptent) is true */
+ 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);
+ if (do_swap_account)
+ entry->val = ent.val;
+ }
+
+ return page;
+}
+
static int is_target_pte_for_mc(struct vm_area_struct *vma,
unsigned long addr, pte_t ptent, union mc_target *target)
{
struct page_cgroup *pc;
int ret = 0;
swp_entry_t ent = { .val = 0 };
- int usage_count = 0;
- bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON,
- &mc.to->move_charge_at_immigrate);
- if (!pte_present(ptent)) {
- /* TODO: handle swap of shmes/tmpfs */
- if (pte_none(ptent) || pte_file(ptent))
- return 0;
- else if (is_swap_pte(ptent)) {
- ent = pte_to_swp_entry(ptent);
- if (!move_anon || non_swap_entry(ent))
- return 0;
- usage_count = mem_cgroup_count_swap_user(ent, &page);
- }
- } else {
- page = vm_normal_page(vma, addr, ptent);
- if (!page || !page_mapped(page))
- return 0;
- /*
- * TODO: We don't move charges of file(including shmem/tmpfs)
- * pages for now.
- */
- if (!move_anon || !PageAnon(page))
- return 0;
- if (!get_page_unless_zero(page))
- return 0;
- usage_count = page_mapcount(page);
- }
- if (usage_count > 1) {
- /*
- * TODO: We don't move charges of shared(used by multiple
- * processes) pages for now.
- */
- if (page)
- put_page(page);
+ if (pte_present(ptent))
+ page = mc_handle_present_pte(vma, addr, ptent);
+ else if (is_swap_pte(ptent))
+ page = mc_handle_swap_pte(vma, addr, ptent, &ent);
+ else if (pte_none(ptent) || pte_file(ptent))
+ page = mc_handle_file_pte(vma, addr, ptent, &ent);
+
+ if (!page && !ent.val)
return 0;
- }
if (page) {
pc = lookup_page_cgroup(page);
/*
if (!ret || !target)
put_page(page);
}
- /* throught */
- if (ent.val && do_swap_account && !ret &&
+ /* There is a swap entry and a page doesn't exist or isn't charged */
+ if (ent.val && !ret &&
css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
ret = MC_TARGET_SWAP;
if (target)
};
if (is_vm_hugetlb_page(vma))
continue;
- /* TODO: We don't move charges of shmem/tmpfs pages for now. */
- if (vma->vm_flags & VM_SHARED)
- continue;
walk_page_range(vma->vm_start, vma->vm_end,
&mem_cgroup_count_precharge_walk);
}
if (mc.precharge) {
__mem_cgroup_cancel_charge(mc.to, mc.precharge);
mc.precharge = 0;
+ memcg_oom_recover(mc.to);
}
/*
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so
if (mc.moved_charge) {
__mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
mc.moved_charge = 0;
+ memcg_oom_recover(mc.from);
}
/* we must fixup refcnts and charges */
if (mc.moved_swap) {
};
if (is_vm_hugetlb_page(vma))
continue;
- /* TODO: We don't move charges of shmem/tmpfs pages for now. */
- if (vma->vm_flags & VM_SHARED)
- continue;
ret = walk_page_range(vma->vm_start, vma->vm_end,
&mem_cgroup_move_charge_walk);
if (ret)
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff