#include <trace/events/vmscan.h>
struct cgroup_subsys mem_cgroup_subsys __read_mostly;
+EXPORT_SYMBOL(mem_cgroup_subsys);
+
#define MEM_CGROUP_RECLAIM_RETRIES 5
static struct mem_cgroup *root_mem_cgroup __read_mostly;
};
/* for encoding cft->private value on file */
-#define _MEM (0)
-#define _MEMSWAP (1)
-#define _OOM_TYPE (2)
+enum res_type {
+ _MEM,
+ _MEMSWAP,
+ _OOM_TYPE,
+};
+
#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)
int nid;
u64 total = 0;
- for_each_node_state(nid, N_HIGH_MEMORY)
+ for_each_node_state(nid, N_MEMORY)
total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
return total;
}
iter != NULL; \
iter = mem_cgroup_iter(NULL, iter, NULL))
-void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
+void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
{
struct mem_cgroup *memcg;
- if (!mm)
- return;
-
rcu_read_lock();
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
if (unlikely(!memcg))
out:
rcu_read_unlock();
}
-EXPORT_SYMBOL(mem_cgroup_count_vm_event);
+EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
/**
* mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
return;
/* make a nodemask where this memcg uses memory from */
- memcg->scan_nodes = node_states[N_HIGH_MEMORY];
+ memcg->scan_nodes = node_states[N_MEMORY];
- for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
+ for_each_node_mask(nid, node_states[N_MEMORY]) {
if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
node_clear(nid, memcg->scan_nodes);
/*
* Check rest of nodes.
*/
- for_each_node_state(nid, N_HIGH_MEMORY) {
+ for_each_node_state(nid, N_MEMORY) {
if (node_isset(nid, memcg->scan_nodes))
continue;
if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
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
- * from local stock and true is returned. If the stock is 0 or charges from a
- * cgroup which is not current target, returns false. This stock will be
- * refilled.
+/**
+ * consume_stock: Try to consume stocked charge on this cpu.
+ * @memcg: memcg to consume from.
+ * @nr_pages: how many pages to charge.
+ *
+ * The charges will only happen if @memcg matches the current cpu's memcg
+ * stock, and at least @nr_pages are available in that stock. Failure to
+ * service an allocation will refill the stock.
+ *
+ * returns true if successful, false otherwise.
*/
-static bool consume_stock(struct mem_cgroup *memcg)
+static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
{
struct memcg_stock_pcp *stock;
bool ret = true;
+ if (nr_pages > CHARGE_BATCH)
+ return false;
+
stock = &get_cpu_var(memcg_stock);
- if (memcg == stock->cached && stock->nr_pages)
- stock->nr_pages--;
+ if (memcg == stock->cached && stock->nr_pages >= nr_pages)
+ stock->nr_pages -= nr_pages;
else /* need to call res_counter_charge */
ret = false;
put_cpu_var(memcg_stock);
};
static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
- unsigned int nr_pages, bool oom_check)
+ unsigned int nr_pages, unsigned int min_pages,
+ bool oom_check)
{
unsigned long csize = nr_pages * PAGE_SIZE;
struct mem_cgroup *mem_over_limit;
} else
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
/*
- * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
- * of regular pages (CHARGE_BATCH), or a single regular page (1).
- *
* Never reclaim on behalf of optional batching, retry with a
* single page instead.
*/
- if (nr_pages == CHARGE_BATCH)
+ if (nr_pages > min_pages)
return CHARGE_RETRY;
if (!(gfp_mask & __GFP_WAIT))
return CHARGE_WOULDBLOCK;
+ if (gfp_mask & __GFP_NORETRY)
+ return CHARGE_NOMEM;
+
ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
return CHARGE_RETRY;
* unlikely to succeed so close to the limit, and we fall back
* to regular pages anyway in case of failure.
*/
- if (nr_pages == 1 && ret)
+ if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret)
return CHARGE_RETRY;
/*
again:
if (*ptr) { /* css should be a valid one */
memcg = *ptr;
- VM_BUG_ON(css_is_removed(&memcg->css));
if (mem_cgroup_is_root(memcg))
goto done;
- if (nr_pages == 1 && consume_stock(memcg))
+ if (consume_stock(memcg, nr_pages))
goto done;
css_get(&memcg->css);
} else {
rcu_read_unlock();
goto done;
}
- if (nr_pages == 1 && consume_stock(memcg)) {
+ if (consume_stock(memcg, nr_pages)) {
/*
* It seems dagerous to access memcg without css_get().
* But considering how consume_stok works, it's not
nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
}
- ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check);
+ ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages,
+ oom_check);
switch (ret) {
case CHARGE_OK:
break;
/*
* A helper function to get mem_cgroup from ID. must be called under
- * rcu_read_lock(). The caller must check css_is_removed() or some if
- * it's concern. (dropping refcnt from swap can be called against removed
- * memcg.)
+ * rcu_read_lock(). The caller is responsible for calling css_tryget if
+ * the mem_cgroup is used for charging. (dropping refcnt from swap can be
+ * called against removed memcg.)
*/
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
{
/* caller should have done css_get */
pc->mem_cgroup = to;
mem_cgroup_charge_statistics(to, anon, nr_pages);
- /*
- * We charges against "to" which may not have any tasks. Then, "to"
- * can be under rmdir(). But in current implementation, caller of
- * this function is just force_empty() and move charge, so it's
- * guaranteed that "to" is never removed. So, we don't check rmdir
- * status here.
- */
move_unlock_mem_cgroup(from, &flags);
ret = 0;
unlock:
return ret;
}
-/*
- * move charges to its parent.
+/**
+ * mem_cgroup_move_parent - moves page to the parent group
+ * @page: the page to move
+ * @pc: page_cgroup of the page
+ * @child: page's cgroup
+ *
+ * move charges to its parent or the root cgroup if the group has no
+ * parent (aka use_hierarchy==0).
+ * Although this might fail (get_page_unless_zero, isolate_lru_page or
+ * mem_cgroup_move_account fails) the failure is always temporary and
+ * it signals a race with a page removal/uncharge or migration. In the
+ * first case the page is on the way out and it will vanish from the LRU
+ * on the next attempt and the call should be retried later.
+ * Isolation from the LRU fails only if page has been isolated from
+ * the LRU since we looked at it and that usually means either global
+ * reclaim or migration going on. The page will either get back to the
+ * LRU or vanish.
+ * Finaly mem_cgroup_move_account fails only if the page got uncharged
+ * (!PageCgroupUsed) or moved to a different group. The page will
+ * disappear in the next attempt.
*/
-
static int mem_cgroup_move_parent(struct page *page,
struct page_cgroup *pc,
struct mem_cgroup *child)
unsigned long uninitialized_var(flags);
int ret;
- /* Is ROOT ? */
- if (mem_cgroup_is_root(child))
- return -EINVAL;
+ VM_BUG_ON(mem_cgroup_is_root(child));
ret = -EBUSY;
if (!get_page_unless_zero(page))
if (!parent)
parent = root_mem_cgroup;
- if (nr_pages > 1)
+ if (nr_pages > 1) {
+ VM_BUG_ON(!PageTransHuge(page));
flags = compound_lock_irqsave(page);
+ }
ret = mem_cgroup_move_account(page, nr_pages,
pc, child, parent);
return;
if (!memcg)
return;
- cgroup_exclude_rmdir(&memcg->css);
__mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
/*
swp_entry_t ent = {.val = page_private(page)};
mem_cgroup_uncharge_swap(ent);
}
- /*
- * At swapin, 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.
- */
- cgroup_release_and_wakeup_rmdir(&memcg->css);
}
void mem_cgroup_commit_charge_swapin(struct page *page,
struct mem_cgroup **memcgp)
{
struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
struct page_cgroup *pc;
enum charge_type ctype;
*memcgp = NULL;
- VM_BUG_ON(PageTransHuge(page));
if (mem_cgroup_disabled())
return;
+ if (PageTransHuge(page))
+ nr_pages <<= compound_order(page);
+
pc = lookup_page_cgroup(page);
lock_page_cgroup(pc);
if (PageCgroupUsed(pc)) {
* charged to the res_counter since we plan on replacing the
* old one and only one page is going to be left afterwards.
*/
- __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false);
+ __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
}
/* remove redundant charge if migration failed*/
if (!memcg)
return;
- /* blocks rmdir() */
- cgroup_exclude_rmdir(&memcg->css);
+
if (!migration_ok) {
used = oldpage;
unused = newpage;
*/
if (anon)
mem_cgroup_uncharge_page(used);
- /*
- * 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.
- */
- cgroup_release_and_wakeup_rmdir(&memcg->css);
}
/*
return nr_reclaimed;
}
-/*
+/**
+ * mem_cgroup_force_empty_list - clears LRU of a group
+ * @memcg: group to clear
+ * @node: NUMA node
+ * @zid: zone id
+ * @lru: lru to to clear
+ *
* Traverse a specified page_cgroup list and try to drop them all. This doesn't
- * reclaim the pages page themselves - it just removes the page_cgroups.
- * Returns true if some page_cgroups were not freed, indicating that the caller
- * must retry this operation.
+ * reclaim the pages page themselves - pages are moved to the parent (or root)
+ * group.
*/
-static bool mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
+static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
int node, int zid, enum lru_list lru)
{
struct lruvec *lruvec;
- unsigned long flags, loop;
+ unsigned long flags;
struct list_head *list;
struct page *busy;
struct zone *zone;
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
list = &lruvec->lists[lru];
- loop = mem_cgroup_get_lru_size(lruvec, lru);
- /* give some margin against EBUSY etc...*/
- loop += 256;
busy = NULL;
- while (loop--) {
+ do {
struct page_cgroup *pc;
struct page *page;
cond_resched();
} else
busy = NULL;
- }
- return !list_empty(list);
+ } while (!list_empty(list));
}
/*
- * make mem_cgroup's charge to be 0 if there is no task.
+ * make mem_cgroup's charge to be 0 if there is no task by moving
+ * all the charges and pages to the parent.
* This enables deleting this mem_cgroup.
+ *
+ * Caller is responsible for holding css reference on the memcg.
*/
-static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
+static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
{
- int ret;
- int node, zid, shrink;
- int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
- struct cgroup *cgrp = memcg->css.cgroup;
+ int node, zid;
- css_get(&memcg->css);
-
- shrink = 0;
- /* should free all ? */
- if (free_all)
- goto try_to_free;
-move_account:
do {
- ret = -EBUSY;
- if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
- goto out;
/* This is for making all *used* pages to be on LRU. */
lru_add_drain_all();
drain_all_stock_sync(memcg);
- ret = 0;
mem_cgroup_start_move(memcg);
- for_each_node_state(node, N_HIGH_MEMORY) {
- for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
+ for_each_node_state(node, N_MEMORY) {
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
enum lru_list lru;
for_each_lru(lru) {
- ret = mem_cgroup_force_empty_list(memcg,
+ mem_cgroup_force_empty_list(memcg,
node, zid, lru);
- if (ret)
- break;
}
}
- if (ret)
- break;
}
mem_cgroup_end_move(memcg);
memcg_oom_recover(memcg);
cond_resched();
- /* "ret" should also be checked to ensure all lists are empty. */
- } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret);
-out:
- css_put(&memcg->css);
- return ret;
-try_to_free:
+ /*
+ * This is a safety check because mem_cgroup_force_empty_list
+ * could have raced with mem_cgroup_replace_page_cache callers
+ * so the lru seemed empty but the page could have been added
+ * right after the check. RES_USAGE should be safe as we always
+ * charge before adding to the LRU.
+ */
+ } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0);
+}
+
+/*
+ * Reclaims as many pages from the given memcg as possible and moves
+ * the rest to the parent.
+ *
+ * Caller is responsible for holding css reference for memcg.
+ */
+static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
+{
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct cgroup *cgrp = memcg->css.cgroup;
+
/* returns EBUSY if there is a task or if we come here twice. */
- if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
- ret = -EBUSY;
- goto out;
- }
+ if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
+ return -EBUSY;
+
/* we call try-to-free pages for make this cgroup empty */
lru_add_drain_all();
/* try to free all pages in this cgroup */
- shrink = 1;
while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
int progress;
- if (signal_pending(current)) {
- ret = -EINTR;
- goto out;
- }
+ if (signal_pending(current))
+ return -EINTR;
+
progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
false);
if (!progress) {
}
lru_add_drain();
- /* try move_account...there may be some *locked* pages. */
- goto move_account;
+ mem_cgroup_reparent_charges(memcg);
+
+ return 0;
}
static int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
{
- return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ int ret;
+
+ if (mem_cgroup_is_root(memcg))
+ return -EINVAL;
+ css_get(&memcg->css);
+ ret = mem_cgroup_force_empty(memcg);
+ css_put(&memcg->css);
+
+ return ret;
}
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
char str[64];
u64 val;
- int type, name, len;
+ int name, len;
+ enum res_type type;
type = MEMFILE_TYPE(cft->private);
name = MEMFILE_ATTR(cft->private);
const char *buffer)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- int type, name;
+ enum res_type type;
+ int name;
unsigned long long val;
int ret;
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- int type, name;
+ int name;
+ enum res_type type;
type = MEMFILE_TYPE(event);
name = MEMFILE_ATTR(event);
total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL);
seq_printf(m, "total=%lu", total_nr);
- for_each_node_state(nid, N_HIGH_MEMORY) {
+ for_each_node_state(nid, N_MEMORY) {
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL);
seq_printf(m, " N%d=%lu", nid, node_nr);
}
file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE);
seq_printf(m, "file=%lu", file_nr);
- for_each_node_state(nid, N_HIGH_MEMORY) {
+ for_each_node_state(nid, N_MEMORY) {
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
LRU_ALL_FILE);
seq_printf(m, " N%d=%lu", nid, node_nr);
anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON);
seq_printf(m, "anon=%lu", anon_nr);
- for_each_node_state(nid, N_HIGH_MEMORY) {
+ for_each_node_state(nid, N_MEMORY) {
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
LRU_ALL_ANON);
seq_printf(m, " N%d=%lu", nid, node_nr);
unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
seq_printf(m, "unevictable=%lu", unevictable_nr);
- for_each_node_state(nid, N_HIGH_MEMORY) {
+ for_each_node_state(nid, N_MEMORY) {
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
BIT(LRU_UNEVICTABLE));
seq_printf(m, " N%d=%lu", nid, node_nr);
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup_thresholds *thresholds;
struct mem_cgroup_threshold_ary *new;
- int type = MEMFILE_TYPE(cft->private);
+ enum res_type type = MEMFILE_TYPE(cft->private);
u64 threshold, usage;
int i, size, ret;
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup_thresholds *thresholds;
struct mem_cgroup_threshold_ary *new;
- int type = MEMFILE_TYPE(cft->private);
+ enum res_type type = MEMFILE_TYPE(cft->private);
u64 usage;
int i, j, size;
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup_eventfd_list *event;
- int type = MEMFILE_TYPE(cft->private);
+ enum res_type type = MEMFILE_TYPE(cft->private);
BUG_ON(type != _OOM_TYPE);
event = kmalloc(sizeof(*event), GFP_KERNEL);
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup_eventfd_list *ev, *tmp;
- int type = MEMFILE_TYPE(cft->private);
+ enum res_type type = MEMFILE_TYPE(cft->private);
BUG_ON(type != _OOM_TYPE);
}
static struct cgroup_subsys_state * __ref
-mem_cgroup_create(struct cgroup *cont)
+mem_cgroup_css_alloc(struct cgroup *cont)
{
struct mem_cgroup *memcg, *parent;
long error = -ENOMEM;
return ERR_PTR(error);
}
-static int mem_cgroup_pre_destroy(struct cgroup *cont)
+static void mem_cgroup_css_offline(struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- return mem_cgroup_force_empty(memcg, false);
+ mem_cgroup_reparent_charges(memcg);
}
-static void mem_cgroup_destroy(struct cgroup *cont)
+static void mem_cgroup_css_free(struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
struct cgroup_subsys mem_cgroup_subsys = {
.name = "memory",
.subsys_id = mem_cgroup_subsys_id,
- .create = mem_cgroup_create,
- .pre_destroy = mem_cgroup_pre_destroy,
- .destroy = mem_cgroup_destroy,
+ .css_alloc = mem_cgroup_css_alloc,
+ .css_offline = mem_cgroup_css_offline,
+ .css_free = mem_cgroup_css_free,
.can_attach = mem_cgroup_can_attach,
.cancel_attach = mem_cgroup_cancel_attach,
.attach = mem_cgroup_move_task,
.base_cftypes = mem_cgroup_files,
.early_init = 0,
.use_id = 1,
- .__DEPRECATED_clear_css_refs = true,
};
#ifdef CONFIG_MEMCG_SWAP
projects / mirror_ubuntu-bionic-kernel.git / blobdiff