#include <linux/memcontrol.h>
#include <linux/cgroup.h>
#include <linux/mm.h>
+#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/smp.h>
#include <linux/page-flags.h>
#include <linux/rcupdate.h>
#include <linux/limits.h>
#include <linux/mutex.h>
+#include <linux/rbtree.h>
#include <linux/slab.h>
#include <linux/swap.h>
+#include <linux/swapops.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/mm_inline.h>
#include <linux/page_cgroup.h>
+#include <linux/cpu.h>
#include "internal.h"
#include <asm/uaccess.h>
#define do_swap_account (0)
#endif
-static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */
+#define SOFTLIMIT_EVENTS_THRESH (1000)
/*
* Statistics for memory cgroup.
*/
MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
- MEM_CGROUP_STAT_MAPPED_FILE, /* # of pages charged as file rss */
+ MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
+ MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
+ MEM_CGROUP_STAT_SOFTLIMIT, /* decrements on each page in/out.
+ used by soft limit implementation */
MEM_CGROUP_STAT_NSTATS,
};
struct mem_cgroup_stat_cpu cpustat[0];
};
+static inline void
+__mem_cgroup_stat_set_safe(struct mem_cgroup_stat_cpu *stat,
+ enum mem_cgroup_stat_index idx, s64 val)
+{
+ stat->count[idx] = val;
+}
+
+static inline s64
+__mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat,
+ enum mem_cgroup_stat_index idx)
+{
+ return stat->count[idx];
+}
+
/*
* For accounting under irq disable, no need for increment preempt count.
*/
unsigned long count[NR_LRU_LISTS];
struct zone_reclaim_stat reclaim_stat;
+ struct rb_node tree_node; /* RB tree node */
+ unsigned long long usage_in_excess;/* Set to the value by which */
+ /* the soft limit is exceeded*/
+ bool on_tree;
+ struct mem_cgroup *mem; /* Back pointer, we cannot */
+ /* use container_of */
};
/* Macro for accessing counter */
#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
};
+/*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_zone {
+ struct rb_root rb_root;
+ spinlock_t lock;
+};
+
+struct mem_cgroup_tree_per_node {
+ struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_tree {
+ struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
/*
* The memory controller data structure. The memory controller controls both
* page cache and RSS per cgroup. We would eventually like to provide
int prev_priority; /* for recording reclaim priority */
/*
- * While reclaiming in a hiearchy, we cache the last child we
+ * While reclaiming in a hierarchy, we cache the last child we
* reclaimed from.
*/
int last_scanned_child;
/* set when res.limit == memsw.limit */
bool memsw_is_minimum;
+ /*
+ * 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;
+
/*
* statistics. This must be placed at the end of memcg.
*/
struct mem_cgroup_stat stat;
};
+/* Stuffs for move charges at task migration. */
+/*
+ * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
+ * left-shifted bitmap of these types.
+ */
+enum move_type {
+ MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
+ NR_MOVE_TYPE,
+};
+
+/* "mc" and its members are protected by cgroup_mutex */
+static struct move_charge_struct {
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ unsigned long precharge;
+ unsigned long moved_charge;
+ unsigned long moved_swap;
+ struct task_struct *moving_task; /* a task moving charges */
+ wait_queue_head_t waitq; /* a waitq for other context */
+} mc = {
+ .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
+};
+
+/*
+ * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
+ * limit reclaim to prevent infinite loops, if they ever occur.
+ */
+#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
+#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
+
enum charge_type {
MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
MEM_CGROUP_CHARGE_TYPE_MAPPED,
#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)
+/*
+ * Reclaim flags for mem_cgroup_hierarchical_reclaim
+ */
+#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
+#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
+#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
+#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
+#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
+#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
+
static void mem_cgroup_get(struct mem_cgroup *mem);
static void mem_cgroup_put(struct mem_cgroup *mem);
static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
+static void drain_all_stock_async(void);
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
+{
+ return &mem->info.nodeinfo[nid]->zoneinfo[zid];
+}
+
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+ return &mem->css;
+}
+
+static struct mem_cgroup_per_zone *
+page_cgroup_zoneinfo(struct page_cgroup *pc)
+{
+ struct mem_cgroup *mem = pc->mem_cgroup;
+ int nid = page_cgroup_nid(pc);
+ int zid = page_cgroup_zid(pc);
+
+ if (!mem)
+ return NULL;
+
+ return mem_cgroup_zoneinfo(mem, nid, zid);
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_node_zone(int nid, int zid)
+{
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_from_page(struct page *page)
+{
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static void
+__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz,
+ unsigned long long new_usage_in_excess)
+{
+ struct rb_node **p = &mctz->rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct mem_cgroup_per_zone *mz_node;
+
+ if (mz->on_tree)
+ return;
+
+ mz->usage_in_excess = new_usage_in_excess;
+ if (!mz->usage_in_excess)
+ return;
+ while (*p) {
+ parent = *p;
+ mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
+ tree_node);
+ if (mz->usage_in_excess < mz_node->usage_in_excess)
+ p = &(*p)->rb_left;
+ /*
+ * We can't avoid mem cgroups that are over their soft
+ * limit by the same amount
+ */
+ else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&mz->tree_node, parent, p);
+ rb_insert_color(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = true;
+}
+
+static void
+__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ if (!mz->on_tree)
+ return;
+ rb_erase(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = false;
+}
+
+static void
+mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ spin_lock(&mctz->lock);
+ __mem_cgroup_remove_exceeded(mem, mz, mctz);
+ spin_unlock(&mctz->lock);
+}
+
+static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
+{
+ bool ret = false;
+ int cpu;
+ s64 val;
+ struct mem_cgroup_stat_cpu *cpustat;
+
+ cpu = get_cpu();
+ cpustat = &mem->stat.cpustat[cpu];
+ val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_SOFTLIMIT);
+ if (unlikely(val < 0)) {
+ __mem_cgroup_stat_set_safe(cpustat, MEM_CGROUP_STAT_SOFTLIMIT,
+ SOFTLIMIT_EVENTS_THRESH);
+ ret = true;
+ }
+ put_cpu();
+ return ret;
+}
+
+static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
+{
+ unsigned long long excess;
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup_tree_per_zone *mctz;
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+ mctz = soft_limit_tree_from_page(page);
+
+ /*
+ * Necessary to update all ancestors when hierarchy is used.
+ * because their event counter is not touched.
+ */
+ for (; mem; mem = parent_mem_cgroup(mem)) {
+ mz = mem_cgroup_zoneinfo(mem, nid, zid);
+ excess = res_counter_soft_limit_excess(&mem->res);
+ /*
+ * We have to update the tree if mz is on RB-tree or
+ * mem is over its softlimit.
+ */
+ if (excess || mz->on_tree) {
+ spin_lock(&mctz->lock);
+ /* if on-tree, remove it */
+ if (mz->on_tree)
+ __mem_cgroup_remove_exceeded(mem, mz, mctz);
+ /*
+ * Insert again. mz->usage_in_excess will be updated.
+ * If excess is 0, no tree ops.
+ */
+ __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
+ spin_unlock(&mctz->lock);
+ }
+ }
+}
+
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
+{
+ int node, zone;
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup_tree_per_zone *mctz;
+
+ for_each_node_state(node, N_POSSIBLE) {
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ mz = mem_cgroup_zoneinfo(mem, node, zone);
+ mctz = soft_limit_tree_node_zone(node, zone);
+ mem_cgroup_remove_exceeded(mem, mz, mctz);
+ }
+ }
+}
+
+static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
+{
+ return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
+}
+
+static struct mem_cgroup_per_zone *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct rb_node *rightmost = NULL;
+ struct mem_cgroup_per_zone *mz;
+
+retry:
+ mz = NULL;
+ rightmost = rb_last(&mctz->rb_root);
+ if (!rightmost)
+ goto done; /* Nothing to reclaim from */
+
+ mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
+ /*
+ * Remove the node now but someone else can add it back,
+ * we will to add it back at the end of reclaim to its correct
+ * position in the tree.
+ */
+ __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
+ if (!res_counter_soft_limit_excess(&mz->mem->res) ||
+ !css_tryget(&mz->mem->css))
+ goto retry;
+done:
+ return mz;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ spin_lock(&mctz->lock);
+ mz = __mem_cgroup_largest_soft_limit_node(mctz);
+ spin_unlock(&mctz->lock);
+ return mz;
+}
+
+static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
+ bool charge)
+{
+ int val = (charge) ? 1 : -1;
+ struct mem_cgroup_stat *stat = &mem->stat;
+ struct mem_cgroup_stat_cpu *cpustat;
+ int cpu = get_cpu();
+
+ cpustat = &stat->cpustat[cpu];
+ __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
+ put_cpu();
+}
static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
struct page_cgroup *pc,
bool charge)
{
- int val = (charge)? 1 : -1;
+ int val = (charge) ? 1 : -1;
struct mem_cgroup_stat *stat = &mem->stat;
struct mem_cgroup_stat_cpu *cpustat;
int cpu = get_cpu();
else
__mem_cgroup_stat_add_safe(cpustat,
MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
+ __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SOFTLIMIT, -1);
put_cpu();
}
-static struct mem_cgroup_per_zone *
-mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
-{
- return &mem->info.nodeinfo[nid]->zoneinfo[zid];
-}
-
-static struct mem_cgroup_per_zone *
-page_cgroup_zoneinfo(struct page_cgroup *pc)
-{
- struct mem_cgroup *mem = pc->mem_cgroup;
- int nid = page_cgroup_nid(pc);
- int zid = page_cgroup_zid(pc);
-
- if (!mem)
- return NULL;
-
- return mem_cgroup_zoneinfo(mem, nid, zid);
-}
-
static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
enum lru_list idx)
{
task_unlock(task);
if (!curr)
return 0;
- if (curr->use_hierarchy)
+ /*
+ * We should check use_hierarchy of "mem" not "curr". Because checking
+ * use_hierarchy of "curr" here make this function true if hierarchy is
+ * 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);
static char memcg_name[PATH_MAX];
int ret;
- if (!memcg)
+ if (!memcg || !p)
return;
* If shrink==true, for avoiding to free too much, this returns immedieately.
*/
static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
- gfp_t gfp_mask, bool noswap, bool shrink)
+ struct zone *zone,
+ gfp_t gfp_mask,
+ unsigned long reclaim_options)
{
struct mem_cgroup *victim;
int ret, total = 0;
int loop = 0;
+ bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
+ bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
+ bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
+ unsigned long excess = mem_cgroup_get_excess(root_mem);
/* If memsw_is_minimum==1, swap-out is of-no-use. */
if (root_mem->memsw_is_minimum)
noswap = true;
- while (loop < 2) {
+ while (1) {
victim = mem_cgroup_select_victim(root_mem);
- if (victim == root_mem)
+ if (victim == root_mem) {
loop++;
+ if (loop >= 1)
+ drain_all_stock_async();
+ if (loop >= 2) {
+ /*
+ * If we have not been able to reclaim
+ * anything, it might because there are
+ * no reclaimable pages under this hierarchy
+ */
+ if (!check_soft || !total) {
+ css_put(&victim->css);
+ break;
+ }
+ /*
+ * We want to do more targetted reclaim.
+ * excess >> 2 is not to excessive so as to
+ * reclaim too much, nor too less that we keep
+ * coming back to reclaim from this cgroup
+ */
+ if (total >= (excess >> 2) ||
+ (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
+ css_put(&victim->css);
+ break;
+ }
+ }
+ }
if (!mem_cgroup_local_usage(&victim->stat)) {
/* this cgroup's local usage == 0 */
css_put(&victim->css);
continue;
}
/* we use swappiness of local cgroup */
- ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap,
- get_swappiness(victim));
+ if (check_soft)
+ ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
+ noswap, get_swappiness(victim), zone,
+ zone->zone_pgdat->node_id);
+ else
+ ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
+ noswap, get_swappiness(victim));
css_put(&victim->css);
/*
* At shrinking usage, we can't check we should stop here or
if (shrink)
return ret;
total += ret;
- if (mem_cgroup_check_under_limit(root_mem))
+ if (check_soft) {
+ if (res_counter_check_under_soft_limit(&root_mem->res))
+ return total;
+ } else if (mem_cgroup_check_under_limit(root_mem))
return 1 + total;
}
return total;
* Currently used to update mapped file statistics, but the routine can be
* generalized to update other statistics as well.
*/
-void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+void mem_cgroup_update_file_mapped(struct page *page, int val)
{
struct mem_cgroup *mem;
struct mem_cgroup_stat *stat;
int cpu;
struct page_cgroup *pc;
- if (!page_is_file_cache(page))
- return;
-
pc = lookup_page_cgroup(page);
if (unlikely(!pc))
return;
stat = &mem->stat;
cpustat = &stat->cpustat[cpu];
- __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+ __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED, val);
done:
unlock_page_cgroup(pc);
}
+/*
+ * size of first charge trial. "32" comes from vmscan.c's magic value.
+ * TODO: maybe necessary to use big numbers in big irons.
+ */
+#define CHARGE_SIZE (32 * PAGE_SIZE)
+struct memcg_stock_pcp {
+ struct mem_cgroup *cached; /* this never be root cgroup */
+ int charge;
+ struct work_struct work;
+};
+static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
+static atomic_t memcg_drain_count;
+
+/*
+ * Try to consume stocked charge on this cpu. If success, PAGE_SIZE 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.
+ */
+static bool consume_stock(struct mem_cgroup *mem)
+{
+ struct memcg_stock_pcp *stock;
+ bool ret = true;
+
+ stock = &get_cpu_var(memcg_stock);
+ if (mem == stock->cached && stock->charge)
+ stock->charge -= PAGE_SIZE;
+ else /* need to call res_counter_charge */
+ ret = false;
+ put_cpu_var(memcg_stock);
+ return ret;
+}
+
+/*
+ * Returns stocks cached in percpu to res_counter and reset cached information.
+ */
+static void drain_stock(struct memcg_stock_pcp *stock)
+{
+ struct mem_cgroup *old = stock->cached;
+
+ if (stock->charge) {
+ res_counter_uncharge(&old->res, stock->charge);
+ if (do_swap_account)
+ res_counter_uncharge(&old->memsw, stock->charge);
+ }
+ stock->cached = NULL;
+ stock->charge = 0;
+}
+
+/*
+ * This must be called under preempt disabled or must be called by
+ * a thread which is pinned to local cpu.
+ */
+static void drain_local_stock(struct work_struct *dummy)
+{
+ struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
+ drain_stock(stock);
+}
+
+/*
+ * Cache charges(val) which is from res_counter, to local per_cpu area.
+ * This will be consumed by consumt_stock() function, later.
+ */
+static void refill_stock(struct mem_cgroup *mem, int val)
+{
+ struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
+
+ if (stock->cached != mem) { /* reset if necessary */
+ drain_stock(stock);
+ stock->cached = mem;
+ }
+ stock->charge += val;
+ put_cpu_var(memcg_stock);
+}
+
+/*
+ * 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(void)
+{
+ int cpu;
+ /* This function is for scheduling "drain" in asynchronous way.
+ * The result of "drain" is not directly handled by callers. Then,
+ * if someone is calling drain, we don't have to call drain more.
+ * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
+ * there is a race. We just do loose check here.
+ */
+ if (atomic_read(&memcg_drain_count))
+ return;
+ /* Notify other cpus that system-wide "drain" is running */
+ atomic_inc(&memcg_drain_count);
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+ schedule_work_on(cpu, &stock->work);
+ }
+ put_online_cpus();
+ atomic_dec(&memcg_drain_count);
+ /* We don't wait for flush_work */
+}
+
+/* This is a synchronous drain interface. */
+static void drain_all_stock_sync(void)
+{
+ /* called when force_empty is called */
+ atomic_inc(&memcg_drain_count);
+ schedule_on_each_cpu(drain_local_stock);
+ atomic_dec(&memcg_drain_count);
+}
+
+static int __cpuinit memcg_stock_cpu_callback(struct notifier_block *nb,
+ unsigned long action,
+ void *hcpu)
+{
+ int cpu = (unsigned long)hcpu;
+ struct memcg_stock_pcp *stock;
+
+ if (action != CPU_DEAD)
+ return NOTIFY_OK;
+ stock = &per_cpu(memcg_stock, cpu);
+ drain_stock(stock);
+ return NOTIFY_OK;
+}
+
/*
* Unlike exported interface, "oom" parameter is added. if oom==true,
* oom-killer can be invoked.
*/
static int __mem_cgroup_try_charge(struct mm_struct *mm,
gfp_t gfp_mask, struct mem_cgroup **memcg,
- bool oom)
+ bool oom, struct page *page)
{
struct mem_cgroup *mem, *mem_over_limit;
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct res_counter *fail_res;
+ int csize = CHARGE_SIZE;
if (unlikely(test_thread_flag(TIF_MEMDIE))) {
/* Don't account this! */
return 0;
VM_BUG_ON(css_is_removed(&mem->css));
+ if (mem_cgroup_is_root(mem))
+ goto done;
while (1) {
- int ret;
- bool noswap = false;
+ int ret = 0;
+ unsigned long flags = 0;
- ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
+ if (consume_stock(mem))
+ goto charged;
+
+ ret = res_counter_charge(&mem->res, csize, &fail_res);
if (likely(!ret)) {
if (!do_swap_account)
break;
- ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
- &fail_res);
+ ret = res_counter_charge(&mem->memsw, csize, &fail_res);
if (likely(!ret))
break;
/* mem+swap counter fails */
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- noswap = true;
+ res_counter_uncharge(&mem->res, csize);
+ flags |= MEM_CGROUP_RECLAIM_NOSWAP;
mem_over_limit = mem_cgroup_from_res_counter(fail_res,
memsw);
} else
mem_over_limit = mem_cgroup_from_res_counter(fail_res,
res);
+ /* reduce request size and retry */
+ if (csize > PAGE_SIZE) {
+ csize = PAGE_SIZE;
+ continue;
+ }
if (!(gfp_mask & __GFP_WAIT))
goto nomem;
- ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
- noswap, false);
+ ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
+ gfp_mask, flags);
if (ret)
continue;
if (mem_cgroup_check_under_limit(mem_over_limit))
continue;
+ /* try to avoid oom while someone is moving charge */
+ if (mc.moving_task && current != mc.moving_task) {
+ struct mem_cgroup *from, *to;
+ bool do_continue = false;
+ /*
+ * 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)) {
+ if (mem_over_limit->use_hierarchy)
+ do_continue = css_is_ancestor(
+ &from->css,
+ &mem_over_limit->css);
+ else
+ do_continue = (from == mem_over_limit);
+ css_put(&from->css);
+ }
+ if (!do_continue && to && css_tryget(&to->css)) {
+ if (mem_over_limit->use_hierarchy)
+ do_continue = css_is_ancestor(
+ &to->css,
+ &mem_over_limit->css);
+ else
+ 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,
+ TASK_INTERRUPTIBLE);
+ /* moving charge context might have finished. */
+ if (mc.moving_task)
+ schedule();
+ finish_wait(&mc.waitq, &wait);
+ continue;
+ }
+ }
+
if (!nr_retries--) {
if (oom) {
- mutex_lock(&memcg_tasklist);
mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
- mutex_unlock(&memcg_tasklist);
record_last_oom(mem_over_limit);
}
goto nomem;
}
}
+ if (csize > PAGE_SIZE)
+ refill_stock(mem, csize - PAGE_SIZE);
+charged:
+ /*
+ * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
+ * if they exceeds softlimit.
+ */
+ if (page && mem_cgroup_soft_limit_check(mem))
+ mem_cgroup_update_tree(mem, page);
+done:
return 0;
nomem:
css_put(&mem->css);
return -ENOMEM;
}
+/*
+ * Somemtimes we have to undo a charge we got by try_charge().
+ * This function is for that and do uncharge, put css's refcnt.
+ * gotten by try_charge().
+ */
+static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
+ unsigned long count)
+{
+ if (!mem_cgroup_is_root(mem)) {
+ res_counter_uncharge(&mem->res, PAGE_SIZE * count);
+ if (do_swap_account)
+ res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
+ VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags));
+ WARN_ON_ONCE(count > INT_MAX);
+ __css_put(&mem->css, (int)count);
+ }
+ /* we don't need css_put for root */
+}
+
+static void mem_cgroup_cancel_charge(struct mem_cgroup *mem)
+{
+ __mem_cgroup_cancel_charge(mem, 1);
+}
/*
* A helper function to get mem_cgroup from ID. must be called under
return container_of(css, struct mem_cgroup, css);
}
-static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
+struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
{
- struct mem_cgroup *mem;
+ struct mem_cgroup *mem = NULL;
struct page_cgroup *pc;
unsigned short id;
swp_entry_t ent;
VM_BUG_ON(!PageLocked(page));
- if (!PageSwapCache(page))
- return NULL;
-
pc = lookup_page_cgroup(page);
lock_page_cgroup(pc);
if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
if (mem && !css_tryget(&mem->css))
mem = NULL;
- } else {
+ } else if (PageSwapCache(page)) {
ent.val = page_private(page);
id = lookup_swap_cgroup(ent);
rcu_read_lock();
lock_page_cgroup(pc);
if (unlikely(PageCgroupUsed(pc))) {
unlock_page_cgroup(pc);
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- if (do_swap_account)
- res_counter_uncharge(&mem->memsw, PAGE_SIZE);
- css_put(&mem->css);
+ mem_cgroup_cancel_charge(mem);
return;
}
pc->mem_cgroup = mem;
+ /*
+ * We access a page_cgroup asynchronously without lock_page_cgroup().
+ * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
+ * is accessed after testing USED bit. To make pc->mem_cgroup visible
+ * before USED bit, we need memory barrier here.
+ * See mem_cgroup_add_lru_list(), etc.
+ */
smp_wmb();
switch (ctype) {
case MEM_CGROUP_CHARGE_TYPE_CACHE:
}
/**
- * mem_cgroup_move_account - move account of the page
+ * __mem_cgroup_move_account - move account of the page
* @pc: page_cgroup of the page.
* @from: mem_cgroup which the page is moved from.
* @to: mem_cgroup which the page is moved to. @from != @to.
+ * @uncharge: whether we should call uncharge and css_put against @from.
*
* The caller must confirm following.
* - page is not on LRU (isolate_page() is useful.)
+ * - the pc is locked, used, and ->mem_cgroup points to @from.
*
- * returns 0 at success,
- * returns -EBUSY when lock is busy or "pc" is unstable.
- *
- * This function does "uncharge" from old cgroup but doesn't do "charge" to
- * new cgroup. It should be done by a caller.
+ * This function doesn't do "charge" nor css_get to new cgroup. It should be
+ * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
+ * true, this function does "uncharge" from old cgroup, but it doesn't if
+ * @uncharge is false, so a caller should do "uncharge".
*/
-static int mem_cgroup_move_account(struct page_cgroup *pc,
- struct mem_cgroup *from, struct mem_cgroup *to)
+static void __mem_cgroup_move_account(struct page_cgroup *pc,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
{
- struct mem_cgroup_per_zone *from_mz, *to_mz;
- int nid, zid;
- int ret = -EBUSY;
struct page *page;
int cpu;
struct mem_cgroup_stat *stat;
VM_BUG_ON(from == to);
VM_BUG_ON(PageLRU(pc->page));
-
- nid = page_cgroup_nid(pc);
- zid = page_cgroup_zid(pc);
- from_mz = mem_cgroup_zoneinfo(from, nid, zid);
- to_mz = mem_cgroup_zoneinfo(to, nid, zid);
-
- if (!trylock_page_cgroup(pc))
- return ret;
-
- if (!PageCgroupUsed(pc))
- goto out;
-
- if (pc->mem_cgroup != from)
- goto out;
-
- res_counter_uncharge(&from->res, PAGE_SIZE);
- mem_cgroup_charge_statistics(from, pc, false);
+ VM_BUG_ON(!PageCgroupLocked(pc));
+ VM_BUG_ON(!PageCgroupUsed(pc));
+ VM_BUG_ON(pc->mem_cgroup != from);
page = pc->page;
- if (page_is_file_cache(page) && page_mapped(page)) {
+ if (page_mapped(page) && !PageAnon(page)) {
cpu = smp_processor_id();
/* Update mapped_file data for mem_cgroup "from" */
stat = &from->stat;
cpustat = &stat->cpustat[cpu];
- __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+ __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
-1);
/* Update mapped_file data for mem_cgroup "to" */
stat = &to->stat;
cpustat = &stat->cpustat[cpu];
- __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+ __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
1);
}
+ mem_cgroup_charge_statistics(from, pc, false);
+ if (uncharge)
+ /* This is not "cancel", but cancel_charge does all we need. */
+ mem_cgroup_cancel_charge(from);
- if (do_swap_account)
- res_counter_uncharge(&from->memsw, PAGE_SIZE);
- css_put(&from->css);
-
- css_get(&to->css);
+ /* caller should have done css_get */
pc->mem_cgroup = to;
mem_cgroup_charge_statistics(to, pc, true);
- ret = 0;
-out:
- unlock_page_cgroup(pc);
/*
* 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 it's garanteed that
- * "to" is never removed. So, we don't check rmdir status here.
+ * this function is just force_empty() and move charge, so it's
+ * garanteed that "to" is never removed. So, we don't check rmdir
+ * status here.
*/
+}
+
+/*
+ * check whether the @pc is valid for moving account and call
+ * __mem_cgroup_move_account()
+ */
+static int mem_cgroup_move_account(struct page_cgroup *pc,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
+{
+ int ret = -EINVAL;
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
+ __mem_cgroup_move_account(pc, from, to, uncharge);
+ ret = 0;
+ }
+ unlock_page_cgroup(pc);
return ret;
}
if (!pcg)
return -EINVAL;
+ ret = -EBUSY;
+ if (!get_page_unless_zero(page))
+ goto out;
+ if (isolate_lru_page(page))
+ goto put;
parent = mem_cgroup_from_cont(pcg);
-
-
- ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
+ ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, page);
if (ret || !parent)
- return ret;
-
- if (!get_page_unless_zero(page)) {
- ret = -EBUSY;
- goto uncharge;
- }
-
- ret = isolate_lru_page(page);
+ goto put_back;
+ ret = mem_cgroup_move_account(pc, child, parent, true);
if (ret)
- goto cancel;
-
- ret = mem_cgroup_move_account(pc, child, parent);
-
+ mem_cgroup_cancel_charge(parent);
+put_back:
putback_lru_page(page);
- if (!ret) {
- put_page(page);
- /* drop extra refcnt by try_charge() */
- css_put(&parent->css);
- return 0;
- }
-
-cancel:
+put:
put_page(page);
-uncharge:
- /* drop extra refcnt by try_charge() */
- css_put(&parent->css);
- /* uncharge if move fails */
- res_counter_uncharge(&parent->res, PAGE_SIZE);
- if (do_swap_account)
- res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+out:
return ret;
}
prefetchw(pc);
mem = memcg;
- ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
+ ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page);
if (ret || !mem)
return ret;
/*
* While swap-in, try_charge -> commit or cancel, the page is locked.
* And when try_charge() successfully returns, one refcnt to memcg without
- * struct page_cgroup is aquired. This refcnt will be cumsumed by
+ * struct page_cgroup is acquired. This refcnt will be consumed by
* "commit()" or removed by "cancel()"
*/
int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
goto charge_cur_mm;
/*
* A racing thread's fault, or swapoff, may have already updated
- * the pte, and even removed page from swap cache: return success
- * to go on to do_swap_page()'s pte_same() test, which should fail.
+ * the pte, and even removed page from swap cache: in those cases
+ * do_swap_page()'s pte_same() test will fail; but there's also a
+ * KSM case which does need to charge the page.
*/
if (!PageSwapCache(page))
- return 0;
- mem = try_get_mem_cgroup_from_swapcache(page);
+ goto charge_cur_mm;
+ mem = try_get_mem_cgroup_from_page(page);
if (!mem)
goto charge_cur_mm;
*ptr = mem;
- ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
+ ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, page);
/* drop extra refcnt from tryget */
css_put(&mem->css);
return ret;
charge_cur_mm:
if (unlikely(!mm))
mm = &init_mm;
- return __mem_cgroup_try_charge(mm, mask, ptr, true);
+ return __mem_cgroup_try_charge(mm, mask, ptr, true, page);
}
static void
* This recorded memcg can be obsolete one. So, avoid
* calling css_tryget
*/
- 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);
mem_cgroup_put(memcg);
}
rcu_read_unlock();
return;
if (!mem)
return;
+ mem_cgroup_cancel_charge(mem);
+}
+
+static void
+__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype)
+{
+ struct memcg_batch_info *batch = NULL;
+ bool uncharge_memsw = true;
+ /* 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;
+ /*
+ * In usual, we do css_get() when we remember memcg pointer.
+ * But in this case, we keep res->usage until end of a series of
+ * uncharges. Then, it's ok to ignore memcg's refcnt.
+ */
+ if (!batch->memcg)
+ batch->memcg = mem;
+ /*
+ * 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.
+ */
+ if (batch->memcg != mem)
+ goto direct_uncharge;
+ /* remember freed charge and uncharge it later */
+ batch->bytes += PAGE_SIZE;
+ if (uncharge_memsw)
+ batch->memsw_bytes += PAGE_SIZE;
+ return;
+direct_uncharge:
res_counter_uncharge(&mem->res, PAGE_SIZE);
- if (do_swap_account)
+ if (uncharge_memsw)
res_counter_uncharge(&mem->memsw, PAGE_SIZE);
- css_put(&mem->css);
+ return;
}
-
/*
* uncharge if !page_mapped(page)
*/
break;
}
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
- res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+ if (!mem_cgroup_is_root(mem))
+ __do_uncharge(mem, ctype);
+ if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
+ mem_cgroup_swap_statistics(mem, true);
mem_cgroup_charge_statistics(mem, pc, false);
ClearPageCgroupUsed(pc);
mz = page_cgroup_zoneinfo(pc);
unlock_page_cgroup(pc);
+ if (mem_cgroup_soft_limit_check(mem))
+ mem_cgroup_update_tree(mem, page);
/* at swapout, this memcg will be accessed to record to swap */
if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
css_put(&mem->css);
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
}
+/*
+ * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
+ * In that cases, pages are freed continuously and we can expect pages
+ * are in the same memcg. All these calls itself limits the number of
+ * pages freed at once, then uncharge_start/end() is called properly.
+ * This may be called prural(2) times in a context,
+ */
+
+void mem_cgroup_uncharge_start(void)
+{
+ current->memcg_batch.do_batch++;
+ /* We can do nest. */
+ if (current->memcg_batch.do_batch == 1) {
+ current->memcg_batch.memcg = NULL;
+ current->memcg_batch.bytes = 0;
+ current->memcg_batch.memsw_bytes = 0;
+ }
+}
+
+void mem_cgroup_uncharge_end(void)
+{
+ struct memcg_batch_info *batch = ¤t->memcg_batch;
+
+ if (!batch->do_batch)
+ return;
+
+ batch->do_batch--;
+ if (batch->do_batch) /* If stacked, do nothing. */
+ return;
+
+ if (!batch->memcg)
+ return;
+ /*
+ * This "batch->memcg" is valid without any css_get/put etc...
+ * bacause we hide charges behind us.
+ */
+ if (batch->bytes)
+ res_counter_uncharge(&batch->memcg->res, batch->bytes);
+ if (batch->memsw_bytes)
+ res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
+ /* forget this pointer (for sanity check) */
+ batch->memcg = NULL;
+}
+
#ifdef CONFIG_SWAP
/*
* called after __delete_from_swap_cache() and drop "page" account.
* We uncharge this because swap is freed.
* This memcg can be obsolete one. We avoid calling css_tryget
*/
- 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);
mem_cgroup_put(memcg);
}
rcu_read_unlock();
}
+
+/**
+ * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
+ * @entry: swap entry to be moved
+ * @from: mem_cgroup which the entry is moved from
+ * @to: mem_cgroup which the entry is moved to
+ * @need_fixup: whether we should fixup res_counters and refcounts.
+ *
+ * It succeeds only when the swap_cgroup's record for this entry is the same
+ * as the mem_cgroup's id of @from.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ *
+ * The caller must have charged to @to, IOW, called res_counter_charge() about
+ * both res and memsw, and called css_get().
+ */
+static int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+{
+ unsigned short old_id, new_id;
+
+ old_id = css_id(&from->css);
+ new_id = css_id(&to->css);
+
+ if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
+ mem_cgroup_swap_statistics(from, false);
+ mem_cgroup_swap_statistics(to, true);
+ /*
+ * This function is only called from task migration context now.
+ * It postpones res_counter and refcount handling till the end
+ * of task migration(mem_cgroup_clear_mc()) for performance
+ * improvement. But we cannot postpone mem_cgroup_get(to)
+ * because if the process that has been moved to @to does
+ * swap-in, the refcount of @to might be decreased to 0.
+ */
+ mem_cgroup_get(to);
+ if (need_fixup) {
+ if (!mem_cgroup_is_root(from))
+ res_counter_uncharge(&from->memsw, PAGE_SIZE);
+ mem_cgroup_put(from);
+ /*
+ * we charged both to->res and to->memsw, so we should
+ * uncharge to->res.
+ */
+ if (!mem_cgroup_is_root(to))
+ res_counter_uncharge(&to->res, PAGE_SIZE);
+ css_put(&to->css);
+ }
+ return 0;
+ }
+ return -EINVAL;
+}
+#else
+static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+{
+ return -EINVAL;
+}
#endif
/*
unlock_page_cgroup(pc);
if (mem) {
- ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
+ ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
+ page);
css_put(&mem->css);
}
*ptr = mem;
unsigned long long val)
{
int retry_count;
- int progress;
u64 memswlimit;
int ret = 0;
int children = mem_cgroup_count_children(memcg);
if (!ret)
break;
- progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
- false, true);
+ mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_SHRINK);
curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
/* Usage is reduced ? */
if (curusage >= oldusage)
if (!ret)
break;
- mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true);
+ mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_NOSWAP |
+ MEM_CGROUP_RECLAIM_SHRINK);
curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
/* Usage is reduced ? */
if (curusage >= oldusage)
return ret;
}
+unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
+ gfp_t gfp_mask, int nid,
+ int zid)
+{
+ unsigned long nr_reclaimed = 0;
+ struct mem_cgroup_per_zone *mz, *next_mz = NULL;
+ unsigned long reclaimed;
+ int loop = 0;
+ struct mem_cgroup_tree_per_zone *mctz;
+ unsigned long long excess;
+
+ if (order > 0)
+ return 0;
+
+ mctz = soft_limit_tree_node_zone(nid, zid);
+ /*
+ * This loop can run a while, specially if mem_cgroup's continuously
+ * keep exceeding their soft limit and putting the system under
+ * pressure
+ */
+ do {
+ if (next_mz)
+ mz = next_mz;
+ else
+ mz = mem_cgroup_largest_soft_limit_node(mctz);
+ if (!mz)
+ break;
+
+ reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
+ gfp_mask,
+ MEM_CGROUP_RECLAIM_SOFT);
+ nr_reclaimed += reclaimed;
+ spin_lock(&mctz->lock);
+
+ /*
+ * If we failed to reclaim anything from this memory cgroup
+ * it is time to move on to the next cgroup
+ */
+ next_mz = NULL;
+ if (!reclaimed) {
+ do {
+ /*
+ * Loop until we find yet another one.
+ *
+ * By the time we get the soft_limit lock
+ * again, someone might have aded the
+ * group back on the RB tree. Iterate to
+ * make sure we get a different mem.
+ * mem_cgroup_largest_soft_limit_node returns
+ * NULL if no other cgroup is present on
+ * the tree
+ */
+ next_mz =
+ __mem_cgroup_largest_soft_limit_node(mctz);
+ if (next_mz == mz) {
+ css_put(&next_mz->mem->css);
+ next_mz = NULL;
+ } else /* next_mz == NULL or other memcg */
+ break;
+ } while (1);
+ }
+ __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
+ excess = res_counter_soft_limit_excess(&mz->mem->res);
+ /*
+ * One school of thought says that we should not add
+ * back the node to the tree if reclaim returns 0.
+ * But our reclaim could return 0, simply because due
+ * to priority we are exposing a smaller subset of
+ * memory to reclaim from. Consider this as a longer
+ * term TODO.
+ */
+ /* If excess == 0, no tree ops */
+ __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
+ spin_unlock(&mctz->lock);
+ css_put(&mz->mem->css);
+ loop++;
+ /*
+ * Could not reclaim anything and there are no more
+ * mem cgroups to try or we seem to be looping without
+ * reclaiming anything.
+ */
+ if (!nr_reclaimed &&
+ (next_mz == NULL ||
+ loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+ break;
+ } while (!nr_reclaimed);
+ if (next_mz)
+ css_put(&next_mz->mem->css);
+ return nr_reclaimed;
+}
+
/*
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
pc = list_entry(list->prev, struct page_cgroup, lru);
if (busy == pc) {
list_move(&pc->lru, list);
- busy = 0;
+ busy = NULL;
spin_unlock_irqrestore(&zone->lru_lock, flags);
continue;
}
if (free_all)
goto try_to_free;
move_account:
- while (mem->res.usage > 0) {
+ do {
ret = -EBUSY;
if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
goto out;
goto out;
/* This is for making all *used* pages to be on LRU. */
lru_add_drain_all();
+ drain_all_stock_sync();
ret = 0;
for_each_node_state(node, N_HIGH_MEMORY) {
for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
if (ret == -ENOMEM)
goto try_to_free;
cond_resched();
- }
- ret = 0;
+ /* "ret" should also be checked to ensure all lists are empty. */
+ } while (mem->res.usage > 0 || ret);
out:
css_put(&mem->css);
return ret;
}
lru_add_drain();
/* try move_account...there may be some *locked* pages. */
- if (mem->res.usage)
- goto move_account;
- ret = 0;
- goto out;
+ goto move_account;
}
int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
cgroup_lock();
/*
- * If parent's use_hiearchy is set, we can't make any modifications
+ * If parent's use_hierarchy is set, we can't make any modifications
* in the child subtrees. If it is unset, then the change can
* occur, provided the current cgroup has no children.
*
return retval;
}
+struct mem_cgroup_idx_data {
+ s64 val;
+ enum mem_cgroup_stat_index idx;
+};
+
+static int
+mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
+{
+ struct mem_cgroup_idx_data *d = data;
+ d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
+ return 0;
+}
+
+static void
+mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
+ enum mem_cgroup_stat_index idx, s64 *val)
+{
+ struct mem_cgroup_idx_data d;
+ d.idx = idx;
+ d.val = 0;
+ mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat);
+ *val = d.val;
+}
+
+static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
+{
+ u64 idx_val, val;
+
+ if (!mem_cgroup_is_root(mem)) {
+ if (!swap)
+ return res_counter_read_u64(&mem->res, RES_USAGE);
+ else
+ return res_counter_read_u64(&mem->memsw, RES_USAGE);
+ }
+
+ mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE, &idx_val);
+ val = idx_val;
+ mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS, &idx_val);
+ val += idx_val;
+
+ if (swap) {
+ mem_cgroup_get_recursive_idx_stat(mem,
+ MEM_CGROUP_STAT_SWAPOUT, &idx_val);
+ val += idx_val;
+ }
+
+ return val << PAGE_SHIFT;
+}
+
static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
{
struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
- u64 val = 0;
+ u64 val;
int type, name;
type = MEMFILE_TYPE(cft->private);
name = MEMFILE_ATTR(cft->private);
switch (type) {
case _MEM:
- val = res_counter_read_u64(&mem->res, name);
+ if (name == RES_USAGE)
+ val = mem_cgroup_usage(mem, false);
+ else
+ val = res_counter_read_u64(&mem->res, name);
break;
case _MEMSWAP:
- val = res_counter_read_u64(&mem->memsw, name);
+ if (name == RES_USAGE)
+ val = mem_cgroup_usage(mem, true);
+ else
+ val = res_counter_read_u64(&mem->memsw, name);
break;
default:
BUG();
else
ret = mem_cgroup_resize_memsw_limit(memcg, val);
break;
+ case RES_SOFT_LIMIT:
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ /*
+ * For memsw, soft limits are hard to implement in terms
+ * of semantics, for now, we support soft limits for
+ * control without swap
+ */
+ if (type == _MEM)
+ ret = res_counter_set_soft_limit(&memcg->res, val);
+ else
+ ret = -EINVAL;
+ break;
default:
ret = -EINVAL; /* should be BUG() ? */
break;
res_counter_reset_failcnt(&mem->memsw);
break;
}
+
return 0;
}
+static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
+}
+
+#ifdef CONFIG_MMU
+static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+
+ if (val >= (1 << NR_MOVE_TYPE))
+ return -EINVAL;
+ /*
+ * We check this value several times in both in can_attach() and
+ * attach(), so we need cgroup lock to prevent this value from being
+ * inconsistent.
+ */
+ cgroup_lock();
+ mem->move_charge_at_immigrate = val;
+ cgroup_unlock();
+
+ return 0;
+}
+#else
+static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ return -ENOSYS;
+}
+#endif
+
/* For read statistics */
enum {
MCS_CACHE,
MCS_RSS,
- MCS_MAPPED_FILE,
+ MCS_FILE_MAPPED,
MCS_PGPGIN,
MCS_PGPGOUT,
+ MCS_SWAP,
MCS_INACTIVE_ANON,
MCS_ACTIVE_ANON,
MCS_INACTIVE_FILE,
{"mapped_file", "total_mapped_file"},
{"pgpgin", "total_pgpgin"},
{"pgpgout", "total_pgpgout"},
+ {"swap", "total_swap"},
{"inactive_anon", "total_inactive_anon"},
{"active_anon", "total_active_anon"},
{"inactive_file", "total_inactive_file"},
s->stat[MCS_CACHE] += val * PAGE_SIZE;
val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
s->stat[MCS_RSS] += val * PAGE_SIZE;
- val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
- s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
+ val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_FILE_MAPPED);
+ s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
s->stat[MCS_PGPGIN] += val;
val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
s->stat[MCS_PGPGOUT] += val;
+ if (do_swap_account) {
+ val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT);
+ s->stat[MCS_SWAP] += val * PAGE_SIZE;
+ }
/* per zone stat */
val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
memset(&mystat, 0, sizeof(mystat));
mem_cgroup_get_local_stat(mem_cont, &mystat);
- for (i = 0; i < NR_MCS_STAT; i++)
+ for (i = 0; i < NR_MCS_STAT; i++) {
+ if (i == MCS_SWAP && !do_swap_account)
+ continue;
cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
+ }
/* Hierarchical information */
{
memset(&mystat, 0, sizeof(mystat));
mem_cgroup_get_total_stat(mem_cont, &mystat);
- for (i = 0; i < NR_MCS_STAT; i++)
+ for (i = 0; i < NR_MCS_STAT; i++) {
+ if (i == MCS_SWAP && !do_swap_account)
+ continue;
cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
-
+ }
#ifdef CONFIG_DEBUG_VM
cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
.write_string = mem_cgroup_write,
.read_u64 = mem_cgroup_read,
},
+ {
+ .name = "soft_limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
+ },
{
.name = "failcnt",
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
.read_u64 = mem_cgroup_swappiness_read,
.write_u64 = mem_cgroup_swappiness_write,
},
+ {
+ .name = "move_charge_at_immigrate",
+ .read_u64 = mem_cgroup_move_charge_read,
+ .write_u64 = mem_cgroup_move_charge_write,
+ },
};
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
mz = &pn->zoneinfo[zone];
for_each_lru(l)
INIT_LIST_HEAD(&mz->lists[l]);
+ mz->usage_in_excess = 0;
+ mz->on_tree = false;
+ mz->mem = mem;
}
return 0;
}
{
int node;
+ mem_cgroup_remove_from_trees(mem);
free_css_id(&mem_cgroup_subsys, &mem->css);
for_each_node_state(node, N_POSSIBLE)
atomic_inc(&mem->refcnt);
}
-static void mem_cgroup_put(struct mem_cgroup *mem)
+static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
{
- if (atomic_dec_and_test(&mem->refcnt)) {
+ if (atomic_sub_and_test(count, &mem->refcnt)) {
struct mem_cgroup *parent = parent_mem_cgroup(mem);
__mem_cgroup_free(mem);
if (parent)
}
}
+static void mem_cgroup_put(struct mem_cgroup *mem)
+{
+ __mem_cgroup_put(mem, 1);
+}
+
/*
* Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
*/
}
#endif
+static int mem_cgroup_soft_limit_tree_init(void)
+{
+ struct mem_cgroup_tree_per_node *rtpn;
+ struct mem_cgroup_tree_per_zone *rtpz;
+ int tmp, node, zone;
+
+ for_each_node_state(node, N_POSSIBLE) {
+ tmp = node;
+ if (!node_state(node, N_NORMAL_MEMORY))
+ tmp = -1;
+ rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
+ if (!rtpn)
+ return 1;
+
+ soft_limit_tree.rb_tree_per_node[node] = rtpn;
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ rtpz = &rtpn->rb_tree_per_zone[zone];
+ rtpz->rb_root = RB_ROOT;
+ spin_lock_init(&rtpz->lock);
+ }
+ }
+ return 0;
+}
+
static struct cgroup_subsys_state * __ref
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
{
for_each_node_state(node, N_POSSIBLE)
if (alloc_mem_cgroup_per_zone_info(mem, node))
goto free_out;
+
/* root ? */
if (cont->parent == NULL) {
+ int cpu;
enable_swap_cgroup();
parent = NULL;
root_mem_cgroup = mem;
+ if (mem_cgroup_soft_limit_tree_init())
+ goto free_out;
+ for_each_possible_cpu(cpu) {
+ struct memcg_stock_pcp *stock =
+ &per_cpu(memcg_stock, cpu);
+ INIT_WORK(&stock->work, drain_local_stock);
+ }
+ hotcpu_notifier(memcg_stock_cpu_callback, 0);
} else {
parent = mem_cgroup_from_cont(cont->parent);
mem->use_hierarchy = parent->use_hierarchy;
if (parent)
mem->swappiness = get_swappiness(parent);
atomic_set(&mem->refcnt, 1);
+ mem->move_charge_at_immigrate = 0;
return &mem->css;
free_out:
__mem_cgroup_free(mem);
return ret;
}
+#ifdef CONFIG_MMU
+/* Handlers for move charge at task migration. */
+#define PRECHARGE_COUNT_AT_ONCE 256
+static int mem_cgroup_do_precharge(unsigned long count)
+{
+ int ret = 0;
+ int batch_count = PRECHARGE_COUNT_AT_ONCE;
+ struct mem_cgroup *mem = mc.to;
+
+ if (mem_cgroup_is_root(mem)) {
+ mc.precharge += count;
+ /* we don't need css_get for root */
+ return ret;
+ }
+ /* try to charge at once */
+ if (count > 1) {
+ struct res_counter *dummy;
+ /*
+ * "mem" cannot be under rmdir() because we've already checked
+ * by cgroup_lock_live_cgroup() that it is not removed and we
+ * are still under the same cgroup_mutex. So we can postpone
+ * css_get().
+ */
+ if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
+ goto one_by_one;
+ if (do_swap_account && res_counter_charge(&mem->memsw,
+ PAGE_SIZE * count, &dummy)) {
+ res_counter_uncharge(&mem->res, PAGE_SIZE * count);
+ goto one_by_one;
+ }
+ mc.precharge += count;
+ VM_BUG_ON(test_bit(CSS_ROOT, &mem->css.flags));
+ WARN_ON_ONCE(count > INT_MAX);
+ __css_get(&mem->css, (int)count);
+ return ret;
+ }
+one_by_one:
+ /* fall back to one by one charge */
+ while (count--) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ if (!batch_count--) {
+ batch_count = PRECHARGE_COUNT_AT_ONCE;
+ cond_resched();
+ }
+ ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem,
+ false, NULL);
+ if (ret || !mem)
+ /* mem_cgroup_clear_mc() will do uncharge later */
+ return -ENOMEM;
+ mc.precharge++;
+ }
+ return ret;
+}
+#else /* !CONFIG_MMU */
+static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
+ struct cgroup *cgroup,
+ struct task_struct *p,
+ bool threadgroup)
+{
+ return 0;
+}
+static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
+ struct cgroup *cgroup,
+ struct task_struct *p,
+ bool threadgroup)
+{
+}
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup *cont,
struct cgroup *old_cont,
struct task_struct *p,
bool threadgroup)
{
- mutex_lock(&memcg_tasklist);
+}
+#endif
+
+/**
+ * is_target_pte_for_mc - check a pte whether it is valid for move charge
+ * @vma: the vma the pte to be checked belongs
+ * @addr: the address corresponding to the pte to be checked
+ * @ptent: the pte to be checked
+ * @target: the pointer the target page or swap ent will be stored(can be NULL)
+ *
+ * Returns
+ * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
+ * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
+ * move charge. if @target is not NULL, the page is stored in target->page
+ * with extra refcnt got(Callers should handle it).
+ * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
+ * target for charge migration. if @target is not NULL, the entry is stored
+ * in target->ent.
+ *
+ * Called with pte lock held.
+ */
+union mc_target {
+ struct page *page;
+ swp_entry_t ent;
+};
+
+enum mc_target_type {
+ MC_TARGET_NONE, /* not used */
+ MC_TARGET_PAGE,
+ MC_TARGET_SWAP,
+};
+
+static int is_target_pte_for_mc(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, union mc_target *target)
+{
+ struct page *page = NULL;
+ 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);
+ return 0;
+ }
+ if (page) {
+ pc = lookup_page_cgroup(page);
+ /*
+ * Do only loose check w/o page_cgroup lock.
+ * mem_cgroup_move_account() checks the pc is valid or not under
+ * the lock.
+ */
+ if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target)
+ target->page = page;
+ }
+ if (!ret || !target)
+ put_page(page);
+ }
+ /* throught */
+ if (ent.val && do_swap_account && !ret &&
+ css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
+ ret = MC_TARGET_SWAP;
+ if (target)
+ target->ent = ent;
+ }
+ return ret;
+}
+
+static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->private;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; pte++, addr += PAGE_SIZE)
+ if (is_target_pte_for_mc(vma, addr, *pte, NULL))
+ mc.precharge++; /* increment precharge temporarily */
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ return 0;
+}
+
+static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
+{
+ unsigned long precharge;
+ struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ struct mm_walk mem_cgroup_count_precharge_walk = {
+ .pmd_entry = mem_cgroup_count_precharge_pte_range,
+ .mm = mm,
+ .private = vma,
+ };
+ 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);
+ }
+ up_read(&mm->mmap_sem);
+
+ precharge = mc.precharge;
+ mc.precharge = 0;
+
+ return precharge;
+}
+
+static int mem_cgroup_precharge_mc(struct mm_struct *mm)
+{
+ return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm));
+}
+
+static void mem_cgroup_clear_mc(void)
+{
+ /* we must uncharge all the leftover precharges from mc.to */
+ if (mc.precharge) {
+ __mem_cgroup_cancel_charge(mc.to, mc.precharge);
+ mc.precharge = 0;
+ }
/*
- * FIXME: It's better to move charges of this process from old
- * memcg to new memcg. But it's just on TODO-List now.
+ * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
+ * we must uncharge here.
*/
- mutex_unlock(&memcg_tasklist);
+ if (mc.moved_charge) {
+ __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
+ mc.moved_charge = 0;
+ }
+ /* we must fixup refcnts and charges */
+ if (mc.moved_swap) {
+ WARN_ON_ONCE(mc.moved_swap > INT_MAX);
+ /* uncharge swap account from the old cgroup */
+ if (!mem_cgroup_is_root(mc.from))
+ res_counter_uncharge(&mc.from->memsw,
+ PAGE_SIZE * mc.moved_swap);
+ __mem_cgroup_put(mc.from, mc.moved_swap);
+
+ if (!mem_cgroup_is_root(mc.to)) {
+ /*
+ * 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);
+ VM_BUG_ON(test_bit(CSS_ROOT, &mc.to->css.flags));
+ __css_put(&mc.to->css, mc.moved_swap);
+ }
+ /* we've already done mem_cgroup_get(mc.to) */
+
+ mc.moved_swap = 0;
+ }
+ mc.from = NULL;
+ mc.to = NULL;
+ mc.moving_task = NULL;
+ wake_up_all(&mc.waitq);
+}
+
+static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
+ struct cgroup *cgroup,
+ struct task_struct *p,
+ bool threadgroup)
+{
+ int ret = 0;
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
+
+ if (mem->move_charge_at_immigrate) {
+ struct mm_struct *mm;
+ struct mem_cgroup *from = mem_cgroup_from_task(p);
+
+ VM_BUG_ON(from == mem);
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return 0;
+ /* We move charges only when we move a owner of the mm */
+ if (mm->owner == p) {
+ VM_BUG_ON(mc.from);
+ VM_BUG_ON(mc.to);
+ VM_BUG_ON(mc.precharge);
+ VM_BUG_ON(mc.moved_charge);
+ VM_BUG_ON(mc.moved_swap);
+ VM_BUG_ON(mc.moving_task);
+ mc.from = from;
+ mc.to = mem;
+ mc.precharge = 0;
+ mc.moved_charge = 0;
+ mc.moved_swap = 0;
+ mc.moving_task = current;
+
+ ret = mem_cgroup_precharge_mc(mm);
+ if (ret)
+ mem_cgroup_clear_mc();
+ }
+ mmput(mm);
+ }
+ return ret;
+}
+
+static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
+ struct cgroup *cgroup,
+ struct task_struct *p,
+ bool threadgroup)
+{
+ mem_cgroup_clear_mc();
+}
+
+static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ int ret = 0;
+ struct vm_area_struct *vma = walk->private;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+retry:
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; addr += PAGE_SIZE) {
+ pte_t ptent = *(pte++);
+ union mc_target target;
+ int type;
+ struct page *page;
+ struct page_cgroup *pc;
+ swp_entry_t ent;
+
+ if (!mc.precharge)
+ break;
+
+ type = is_target_pte_for_mc(vma, addr, ptent, &target);
+ switch (type) {
+ case MC_TARGET_PAGE:
+ page = target.page;
+ if (isolate_lru_page(page))
+ goto put;
+ pc = lookup_page_cgroup(page);
+ if (!mem_cgroup_move_account(pc,
+ mc.from, mc.to, false)) {
+ mc.precharge--;
+ /* we uncharge from mc.from later. */
+ mc.moved_charge++;
+ }
+ putback_lru_page(page);
+put: /* is_target_pte_for_mc() gets the page */
+ put_page(page);
+ break;
+ case MC_TARGET_SWAP:
+ ent = target.ent;
+ if (!mem_cgroup_move_swap_account(ent,
+ mc.from, mc.to, false)) {
+ mc.precharge--;
+ /* we fixup refcnts and charges later. */
+ mc.moved_swap++;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ if (addr != end) {
+ /*
+ * We have consumed all precharges we got in can_attach().
+ * We try charge one by one, but don't do any additional
+ * charges to mc.to if we have failed in charge once in attach()
+ * phase.
+ */
+ ret = mem_cgroup_do_precharge(1);
+ if (!ret)
+ goto retry;
+ }
+
+ return ret;
+}
+
+static void mem_cgroup_move_charge(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+
+ lru_add_drain_all();
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ int ret;
+ struct mm_walk mem_cgroup_move_charge_walk = {
+ .pmd_entry = mem_cgroup_move_charge_pte_range,
+ .mm = mm,
+ .private = vma,
+ };
+ 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)
+ /*
+ * means we have consumed all precharges and failed in
+ * doing additional charge. Just abandon here.
+ */
+ break;
+ }
+ up_read(&mm->mmap_sem);
+}
+
+static void mem_cgroup_move_task(struct cgroup_subsys *ss,
+ struct cgroup *cont,
+ struct cgroup *old_cont,
+ struct task_struct *p,
+ bool threadgroup)
+{
+ struct mm_struct *mm;
+
+ if (!mc.to)
+ /* no need to move charge */
+ return;
+
+ mm = get_task_mm(p);
+ if (mm) {
+ mem_cgroup_move_charge(mm);
+ mmput(mm);
+ }
+ mem_cgroup_clear_mc();
}
struct cgroup_subsys mem_cgroup_subsys = {
.pre_destroy = mem_cgroup_pre_destroy,
.destroy = mem_cgroup_destroy,
.populate = mem_cgroup_populate,
+ .can_attach = mem_cgroup_can_attach,
+ .cancel_attach = mem_cgroup_cancel_attach,
.attach = mem_cgroup_move_task,
.early_init = 0,
.use_id = 1,
Code Review / linux-2.6.git / blobdiff