#include <linux/memcontrol.h>
#include <linux/cgroup.h>
#include <linux/mm.h>
+#include <linux/smp.h>
#include <linux/page-flags.h>
#include <linux/backing-dev.h>
#include <linux/bit_spinlock.h>
#include <linux/rcupdate.h>
+#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
-struct cgroup_subsys mem_cgroup_subsys;
-static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
+#include <asm/uaccess.h>
+
+struct cgroup_subsys mem_cgroup_subsys __read_mostly;
+static struct kmem_cache *page_cgroup_cache __read_mostly;
+#define MEM_CGROUP_RECLAIM_RETRIES 5
+
+/*
+ * Statistics for memory cgroup.
+ */
+enum mem_cgroup_stat_index {
+ /*
+ * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
+ */
+ MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
+ MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */
+ MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
+ MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
+
+ MEM_CGROUP_STAT_NSTATS,
+};
+
+struct mem_cgroup_stat_cpu {
+ s64 count[MEM_CGROUP_STAT_NSTATS];
+} ____cacheline_aligned_in_smp;
+
+struct mem_cgroup_stat {
+ struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
+};
+
+/*
+ * For accounting under irq disable, no need for increment preempt count.
+ */
+static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat,
+ enum mem_cgroup_stat_index idx, int val)
+{
+ int cpu = smp_processor_id();
+ stat->cpustat[cpu].count[idx] += val;
+}
+
+static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
+ enum mem_cgroup_stat_index idx)
+{
+ int cpu;
+ s64 ret = 0;
+ for_each_possible_cpu(cpu)
+ ret += stat->cpustat[cpu].count[idx];
+ return ret;
+}
+
+/*
+ * per-zone information in memory controller.
+ */
+
+enum mem_cgroup_zstat_index {
+ MEM_CGROUP_ZSTAT_ACTIVE,
+ MEM_CGROUP_ZSTAT_INACTIVE,
+
+ NR_MEM_CGROUP_ZSTAT,
+};
+
+struct mem_cgroup_per_zone {
+ /*
+ * spin_lock to protect the per cgroup LRU
+ */
+ spinlock_t lru_lock;
+ struct list_head active_list;
+ struct list_head inactive_list;
+ unsigned long count[NR_MEM_CGROUP_ZSTAT];
+};
+/* Macro for accessing counter */
+#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
+
+struct mem_cgroup_per_node {
+ struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_lru_info {
+ struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
+};
/*
* The memory controller data structure. The memory controller controls both
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
- * TODO: Consider making these lists per zone
*/
- struct list_head active_list;
- struct list_head inactive_list;
+ struct mem_cgroup_lru_info info;
+
+ int prev_priority; /* for recording reclaim priority */
/*
- * spin_lock to protect the per cgroup LRU
+ * statistics.
*/
- spinlock_t lru_lock;
+ struct mem_cgroup_stat stat;
};
+static struct mem_cgroup init_mem_cgroup;
/*
* We use the lower bit of the page->page_cgroup pointer as a bit spin
- * lock. We need to ensure that page->page_cgroup is atleast two
- * byte aligned (based on comments from Nick Piggin)
+ * lock. We need to ensure that page->page_cgroup is at least two
+ * byte aligned (based on comments from Nick Piggin). But since
+ * bit_spin_lock doesn't actually set that lock bit in a non-debug
+ * uniprocessor kernel, we should avoid setting it here too.
*/
#define PAGE_CGROUP_LOCK_BIT 0x0
-#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
+#else
+#define PAGE_CGROUP_LOCK 0x0
+#endif
/*
* A page_cgroup page is associated with every page descriptor. The
struct list_head lru; /* per cgroup LRU list */
struct page *page;
struct mem_cgroup *mem_cgroup;
- atomic_t ref_cnt; /* Helpful when pages move b/w */
- /* mapped and cached states */
+ int flags;
};
+#define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
+#define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
+
+static int page_cgroup_nid(struct page_cgroup *pc)
+{
+ return page_to_nid(pc->page);
+}
+
+static enum zone_type page_cgroup_zid(struct page_cgroup *pc)
+{
+ return page_zonenum(pc->page);
+}
+enum charge_type {
+ MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED,
+ MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
+};
-static inline
-struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
+/*
+ * Always modified under lru lock. Then, not necessary to preempt_disable()
+ */
+static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags,
+ bool charge)
+{
+ int val = (charge)? 1 : -1;
+ struct mem_cgroup_stat *stat = &mem->stat;
+
+ VM_BUG_ON(!irqs_disabled());
+ if (flags & PAGE_CGROUP_FLAG_CACHE)
+ __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_CACHE, val);
+ else
+ __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);
+
+ if (charge)
+ __mem_cgroup_stat_add_safe(stat,
+ MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
+ else
+ __mem_cgroup_stat_add_safe(stat,
+ MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
+}
+
+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);
+
+ return mem_cgroup_zoneinfo(mem, nid, zid);
+}
+
+static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
+ enum mem_cgroup_zstat_index idx)
+{
+ int nid, zid;
+ struct mem_cgroup_per_zone *mz;
+ u64 total = 0;
+
+ for_each_online_node(nid)
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = mem_cgroup_zoneinfo(mem, nid, zid);
+ total += MEM_CGROUP_ZSTAT(mz, idx);
+ }
+ return total;
+}
+
+static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
{
return container_of(cgroup_subsys_state(cont,
mem_cgroup_subsys_id), struct mem_cgroup,
css);
}
-static inline
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
{
+ /*
+ * mm_update_next_owner() may clear mm->owner to NULL
+ * if it races with swapoff, page migration, etc.
+ * So this can be called with p == NULL.
+ */
+ if (unlikely(!p))
+ return NULL;
+
return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
struct mem_cgroup, css);
}
-void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p)
+static inline int page_cgroup_locked(struct page *page)
{
- struct mem_cgroup *mem;
-
- mem = mem_cgroup_from_task(p);
- css_get(&mem->css);
- mm->mem_cgroup = mem;
+ return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
}
-void mm_free_cgroup(struct mm_struct *mm)
+static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
{
- css_put(&mm->mem_cgroup->css);
+ VM_BUG_ON(!page_cgroup_locked(page));
+ page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK);
}
-static inline int page_cgroup_locked(struct page *page)
+struct page_cgroup *page_get_page_cgroup(struct page *page)
{
- return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT,
- &page->page_cgroup);
+ return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK);
}
-void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
+static void lock_page_cgroup(struct page *page)
{
- int locked;
+ bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
+}
- /*
- * While resetting the page_cgroup we might not hold the
- * page_cgroup lock. free_hot_cold_page() is an example
- * of such a scenario
- */
- if (pc)
- VM_BUG_ON(!page_cgroup_locked(page));
- locked = (page->page_cgroup & PAGE_CGROUP_LOCK);
- page->page_cgroup = ((unsigned long)pc | locked);
+static int try_lock_page_cgroup(struct page *page)
+{
+ return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
}
-struct page_cgroup *page_get_page_cgroup(struct page *page)
+static void unlock_page_cgroup(struct page *page)
{
- return (struct page_cgroup *)
- (page->page_cgroup & ~PAGE_CGROUP_LOCK);
+ bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
}
-void __always_inline lock_page_cgroup(struct page *page)
+static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
+ struct page_cgroup *pc)
{
- bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
- VM_BUG_ON(!page_cgroup_locked(page));
+ int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
+
+ if (from)
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
+ else
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
+
+ mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false);
+ list_del(&pc->lru);
}
-void __always_inline unlock_page_cgroup(struct page *page)
+static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz,
+ struct page_cgroup *pc)
{
- bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
+ int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
+
+ if (!to) {
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
+ list_add(&pc->lru, &mz->inactive_list);
+ } else {
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
+ list_add(&pc->lru, &mz->active_list);
+ }
+ mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true);
}
-void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
+static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
{
- if (active)
- list_move(&pc->lru, &pc->mem_cgroup->active_list);
+ int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
+ struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
+
+ if (from)
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
else
- list_move(&pc->lru, &pc->mem_cgroup->inactive_list);
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
+
+ if (active) {
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
+ pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
+ list_move(&pc->lru, &mz->active_list);
+ } else {
+ MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
+ pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE;
+ list_move(&pc->lru, &mz->inactive_list);
+ }
+}
+
+int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
+{
+ int ret;
+
+ task_lock(task);
+ ret = task->mm && mm_match_cgroup(task->mm, mem);
+ task_unlock(task);
+ return ret;
}
/*
* This routine assumes that the appropriate zone's lru lock is already held
*/
-void mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
+void mem_cgroup_move_lists(struct page *page, bool active)
{
- struct mem_cgroup *mem;
- if (!pc)
+ struct page_cgroup *pc;
+ struct mem_cgroup_per_zone *mz;
+ unsigned long flags;
+
+ if (mem_cgroup_subsys.disabled)
return;
- mem = pc->mem_cgroup;
+ /*
+ * We cannot lock_page_cgroup while holding zone's lru_lock,
+ * because other holders of lock_page_cgroup can be interrupted
+ * with an attempt to rotate_reclaimable_page. But we cannot
+ * safely get to page_cgroup without it, so just try_lock it:
+ * mem_cgroup_isolate_pages allows for page left on wrong list.
+ */
+ if (!try_lock_page_cgroup(page))
+ return;
+
+ pc = page_get_page_cgroup(page);
+ if (pc) {
+ mz = page_cgroup_zoneinfo(pc);
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ __mem_cgroup_move_lists(pc, active);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+ }
+ unlock_page_cgroup(page);
+}
+
+/*
+ * Calculate mapped_ratio under memory controller. This will be used in
+ * vmscan.c for deteremining we have to reclaim mapped pages.
+ */
+int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
+{
+ long total, rss;
+
+ /*
+ * usage is recorded in bytes. But, here, we assume the number of
+ * physical pages can be represented by "long" on any arch.
+ */
+ total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
+ rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
+ return (int)((rss * 100L) / total);
+}
+
+/*
+ * This function is called from vmscan.c. In page reclaiming loop. balance
+ * between active and inactive list is calculated. For memory controller
+ * page reclaiming, we should use using mem_cgroup's imbalance rather than
+ * zone's global lru imbalance.
+ */
+long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
+{
+ unsigned long active, inactive;
+ /* active and inactive are the number of pages. 'long' is ok.*/
+ active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE);
+ inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
+ return (long) (active / (inactive + 1));
+}
+
+/*
+ * prev_priority control...this will be used in memory reclaim path.
+ */
+int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
+{
+ return mem->prev_priority;
+}
+
+void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
+{
+ if (priority < mem->prev_priority)
+ mem->prev_priority = priority;
+}
- spin_lock(&mem->lru_lock);
- __mem_cgroup_move_lists(pc, active);
- spin_unlock(&mem->lru_lock);
+void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
+{
+ mem->prev_priority = priority;
+}
+
+/*
+ * Calculate # of pages to be scanned in this priority/zone.
+ * See also vmscan.c
+ *
+ * priority starts from "DEF_PRIORITY" and decremented in each loop.
+ * (see include/linux/mmzone.h)
+ */
+
+long mem_cgroup_calc_reclaim_active(struct mem_cgroup *mem,
+ struct zone *zone, int priority)
+{
+ long nr_active;
+ int nid = zone->zone_pgdat->node_id;
+ int zid = zone_idx(zone);
+ struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
+
+ nr_active = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE);
+ return (nr_active >> priority);
+}
+
+long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem,
+ struct zone *zone, int priority)
+{
+ long nr_inactive;
+ int nid = zone->zone_pgdat->node_id;
+ int zid = zone_idx(zone);
+ struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
+
+ nr_inactive = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE);
+ return (nr_inactive >> priority);
}
unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
unsigned long scan;
LIST_HEAD(pc_list);
struct list_head *src;
- struct page_cgroup *pc;
+ struct page_cgroup *pc, *tmp;
+ int nid = z->zone_pgdat->node_id;
+ int zid = zone_idx(z);
+ struct mem_cgroup_per_zone *mz;
+ BUG_ON(!mem_cont);
+ mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
if (active)
- src = &mem_cont->active_list;
+ src = &mz->active_list;
else
- src = &mem_cont->inactive_list;
+ src = &mz->inactive_list;
+
- spin_lock(&mem_cont->lru_lock);
- for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
- pc = list_entry(src->prev, struct page_cgroup, lru);
+ spin_lock(&mz->lru_lock);
+ scan = 0;
+ list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
+ if (scan >= nr_to_scan)
+ break;
page = pc->page;
- VM_BUG_ON(!pc);
+
+ if (unlikely(!PageLRU(page)))
+ continue;
if (PageActive(page) && !active) {
__mem_cgroup_move_lists(pc, true);
- scan--;
continue;
}
if (!PageActive(page) && active) {
__mem_cgroup_move_lists(pc, false);
- scan--;
continue;
}
- /*
- * Reclaim, per zone
- * TODO: make the active/inactive lists per zone
- */
- if (page_zone(page) != z)
- continue;
-
- /*
- * Check if the meta page went away from under us
- */
- if (!list_empty(&pc->lru))
- list_move(&pc->lru, &pc_list);
- else
- continue;
+ scan++;
+ list_move(&pc->lru, &pc_list);
if (__isolate_lru_page(page, mode) == 0) {
list_move(&page->lru, dst);
}
list_splice(&pc_list, src);
- spin_unlock(&mem_cont->lru_lock);
+ spin_unlock(&mz->lru_lock);
*scanned = scan;
return nr_taken;
* 0 if the charge was successful
* < 0 if the cgroup is over its limit
*/
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask, enum charge_type ctype,
+ struct mem_cgroup *memcg)
{
struct mem_cgroup *mem;
- struct page_cgroup *pc, *race_pc;
+ struct page_cgroup *pc;
unsigned long flags;
unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct mem_cgroup_per_zone *mz;
- /*
- * Should page_cgroup's go to their own slab?
- * One could optimize the performance of the charging routine
- * by saving a bit in the page_flags and using it as a lock
- * to see if the cgroup page already has a page_cgroup associated
- * with it
- */
-retry:
- lock_page_cgroup(page);
- pc = page_get_page_cgroup(page);
- /*
- * The page_cgroup exists and the page has already been accounted
- */
- if (pc) {
- if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {
- /* this page is under being uncharged ? */
- unlock_page_cgroup(page);
- cpu_relax();
- goto retry;
- } else
- goto done;
- }
-
- unlock_page_cgroup(page);
-
- pc = kzalloc(sizeof(struct page_cgroup), GFP_KERNEL);
- if (pc == NULL)
+ pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
+ if (unlikely(pc == NULL))
goto err;
- rcu_read_lock();
/*
- * We always charge the cgroup the mm_struct belongs to
- * the mm_struct's mem_cgroup changes on task migration if the
+ * We always charge the cgroup the mm_struct belongs to.
+ * The mm_struct's mem_cgroup changes on task migration if the
* thread group leader migrates. It's possible that mm is not
* set, if so charge the init_mm (happens for pagecache usage).
*/
- if (!mm)
- mm = &init_mm;
-
- mem = rcu_dereference(mm->mem_cgroup);
- /*
- * For every charge from the cgroup, increment reference
- * count
- */
- css_get(&mem->css);
- rcu_read_unlock();
+ if (likely(!memcg)) {
+ rcu_read_lock();
+ mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!mem)) {
+ rcu_read_unlock();
+ kmem_cache_free(page_cgroup_cache, pc);
+ return 0;
+ }
+ /*
+ * For every charge from the cgroup, increment reference count
+ */
+ css_get(&mem->css);
+ rcu_read_unlock();
+ } else {
+ mem = memcg;
+ css_get(&memcg->css);
+ }
- /*
- * If we created the page_cgroup, we should free it on exceeding
- * the cgroup limit.
- */
while (res_counter_charge(&mem->res, PAGE_SIZE)) {
- if (try_to_free_mem_cgroup_pages(mem))
+ if (!(gfp_mask & __GFP_WAIT))
+ goto out;
+
+ if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
continue;
/*
- * try_to_free_mem_cgroup_pages() might not give us a full
- * picture of reclaim. Some pages are reclaimed and might be
- * moved to swap cache or just unmapped from the cgroup.
- * Check the limit again to see if the reclaim reduced the
- * current usage of the cgroup before giving up
- */
+ * try_to_free_mem_cgroup_pages() might not give us a full
+ * picture of reclaim. Some pages are reclaimed and might be
+ * moved to swap cache or just unmapped from the cgroup.
+ * Check the limit again to see if the reclaim reduced the
+ * current usage of the cgroup before giving up
+ */
if (res_counter_check_under_limit(&mem->res))
continue;
- /*
- * Since we control both RSS and cache, we end up with a
- * very interesting scenario where we end up reclaiming
- * memory (essentially RSS), since the memory is pushed
- * to swap cache, we eventually end up adding those
- * pages back to our list. Hence we give ourselves a
- * few chances before we fail
- */
- else if (nr_retries--) {
- congestion_wait(WRITE, HZ/10);
- continue;
- }
- css_put(&mem->css);
- mem_cgroup_out_of_memory(mem, GFP_KERNEL);
- goto free_pc;
+ if (!nr_retries--) {
+ mem_cgroup_out_of_memory(mem, gfp_mask);
+ goto out;
+ }
}
- lock_page_cgroup(page);
+ pc->mem_cgroup = mem;
+ pc->page = page;
/*
- * Check if somebody else beat us to allocating the page_cgroup
+ * If a page is accounted as a page cache, insert to inactive list.
+ * If anon, insert to active list.
*/
- race_pc = page_get_page_cgroup(page);
- if (race_pc) {
- kfree(pc);
- pc = race_pc;
- atomic_inc(&pc->ref_cnt);
+ if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
+ pc->flags = PAGE_CGROUP_FLAG_CACHE;
+ else
+ pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
+
+ lock_page_cgroup(page);
+ if (unlikely(page_get_page_cgroup(page))) {
+ unlock_page_cgroup(page);
res_counter_uncharge(&mem->res, PAGE_SIZE);
css_put(&mem->css);
+ kmem_cache_free(page_cgroup_cache, pc);
goto done;
}
-
- atomic_set(&pc->ref_cnt, 1);
- pc->mem_cgroup = mem;
- pc->page = page;
page_assign_page_cgroup(page, pc);
- spin_lock_irqsave(&mem->lru_lock, flags);
- list_add(&pc->lru, &mem->active_list);
- spin_unlock_irqrestore(&mem->lru_lock, flags);
+ mz = page_cgroup_zoneinfo(pc);
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ __mem_cgroup_add_list(mz, pc);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
-done:
unlock_page_cgroup(page);
+done:
return 0;
-free_pc:
- kfree(pc);
+out:
+ css_put(&mem->css);
+ kmem_cache_free(page_cgroup_cache, pc);
err:
return -ENOMEM;
}
+int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
+{
+ if (mem_cgroup_subsys.disabled)
+ return 0;
+
+ /*
+ * If already mapped, we don't have to account.
+ * If page cache, page->mapping has address_space.
+ * But page->mapping may have out-of-use anon_vma pointer,
+ * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
+ * is NULL.
+ */
+ if (page_mapped(page) || (page->mapping && !PageAnon(page)))
+ return 0;
+ if (unlikely(!mm))
+ mm = &init_mm;
+ return mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
+}
+
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask)
+{
+ if (mem_cgroup_subsys.disabled)
+ return 0;
+
+ /*
+ * Corner case handling. This is called from add_to_page_cache()
+ * in usual. But some FS (shmem) precharges this page before calling it
+ * and call add_to_page_cache() with GFP_NOWAIT.
+ *
+ * For GFP_NOWAIT case, the page may be pre-charged before calling
+ * add_to_page_cache(). (See shmem.c) check it here and avoid to call
+ * charge twice. (It works but has to pay a bit larger cost.)
+ */
+ if (!(gfp_mask & __GFP_WAIT)) {
+ struct page_cgroup *pc;
+
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
+ if (pc) {
+ VM_BUG_ON(pc->page != page);
+ VM_BUG_ON(!pc->mem_cgroup);
+ unlock_page_cgroup(page);
+ return 0;
+ }
+ unlock_page_cgroup(page);
+ }
+
+ if (unlikely(!mm))
+ mm = &init_mm;
+
+ return mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
+}
+
/*
- * Uncharging is always a welcome operation, we never complain, simply
- * uncharge.
+ * uncharge if !page_mapped(page)
*/
-void mem_cgroup_uncharge(struct page_cgroup *pc)
+static void
+__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
{
+ struct page_cgroup *pc;
struct mem_cgroup *mem;
- struct page *page;
+ struct mem_cgroup_per_zone *mz;
unsigned long flags;
- if (!pc)
+ if (mem_cgroup_subsys.disabled)
return;
- if (atomic_dec_and_test(&pc->ref_cnt)) {
- page = pc->page;
- lock_page_cgroup(page);
+ /*
+ * Check if our page_cgroup is valid
+ */
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
+ if (unlikely(!pc))
+ goto unlock;
+
+ VM_BUG_ON(pc->page != page);
+
+ if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
+ && ((pc->flags & PAGE_CGROUP_FLAG_CACHE)
+ || page_mapped(page)))
+ goto unlock;
+
+ mz = page_cgroup_zoneinfo(pc);
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ __mem_cgroup_remove_list(mz, pc);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+
+ page_assign_page_cgroup(page, NULL);
+ unlock_page_cgroup(page);
+
+ mem = pc->mem_cgroup;
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
+ css_put(&mem->css);
+
+ kmem_cache_free(page_cgroup_cache, pc);
+ return;
+unlock:
+ unlock_page_cgroup(page);
+}
+
+void mem_cgroup_uncharge_page(struct page *page)
+{
+ __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
+void mem_cgroup_uncharge_cache_page(struct page *page)
+{
+ VM_BUG_ON(page_mapped(page));
+ __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
+}
+
+/*
+ * Before starting migration, account against new page.
+ */
+int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
+{
+ struct page_cgroup *pc;
+ struct mem_cgroup *mem = NULL;
+ enum charge_type ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
+ int ret = 0;
+
+ if (mem_cgroup_subsys.disabled)
+ return 0;
+
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
+ if (pc) {
mem = pc->mem_cgroup;
+ css_get(&mem->css);
+ if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
+ ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+ }
+ unlock_page_cgroup(page);
+ if (mem) {
+ ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
+ ctype, mem);
css_put(&mem->css);
- page_assign_page_cgroup(page, NULL);
- unlock_page_cgroup(page);
- res_counter_uncharge(&mem->res, PAGE_SIZE);
+ }
+ return ret;
+}
+
+/* remove redundant charge if migration failed*/
+void mem_cgroup_end_migration(struct page *newpage)
+{
+ /*
+ * At success, page->mapping is not NULL.
+ * special rollback care is necessary when
+ * 1. at migration failure. (newpage->mapping is cleared in this case)
+ * 2. the newpage was moved but not remapped again because the task
+ * exits and the newpage is obsolete. In this case, the new page
+ * may be a swapcache. So, we just call mem_cgroup_uncharge_page()
+ * always for avoiding mess. The page_cgroup will be removed if
+ * unnecessary. File cache pages is still on radix-tree. Don't
+ * care it.
+ */
+ if (!newpage->mapping)
+ __mem_cgroup_uncharge_common(newpage,
+ MEM_CGROUP_CHARGE_TYPE_FORCE);
+ else if (PageAnon(newpage))
+ mem_cgroup_uncharge_page(newpage);
+}
+
+/*
+ * A call to try to shrink memory usage under specified resource controller.
+ * This is typically used for page reclaiming for shmem for reducing side
+ * effect of page allocation from shmem, which is used by some mem_cgroup.
+ */
+int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
+{
+ struct mem_cgroup *mem;
+ int progress = 0;
+ int retry = MEM_CGROUP_RECLAIM_RETRIES;
- spin_lock_irqsave(&mem->lru_lock, flags);
- list_del_init(&pc->lru);
- spin_unlock_irqrestore(&mem->lru_lock, flags);
- kfree(pc);
+ if (mem_cgroup_subsys.disabled)
+ return 0;
+ if (!mm)
+ return 0;
+
+ rcu_read_lock();
+ mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!mem)) {
+ rcu_read_unlock();
+ return 0;
}
+ css_get(&mem->css);
+ rcu_read_unlock();
+
+ do {
+ progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
+ progress += res_counter_check_under_limit(&mem->res);
+ } while (!progress && --retry);
+
+ css_put(&mem->css);
+ if (!retry)
+ return -ENOMEM;
+ return 0;
}
-int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp)
+int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val)
{
- *tmp = memparse(buf, &buf);
- if (*buf != '\0')
- return -EINVAL;
+ int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
+ int progress;
+ int ret = 0;
+
+ while (res_counter_set_limit(&memcg->res, val)) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ if (!retry_count) {
+ ret = -EBUSY;
+ break;
+ }
+ progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
+ if (!progress)
+ retry_count--;
+ }
+ return ret;
+}
+
+
+/*
+ * This routine traverse page_cgroup in given list and drop them all.
+ * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
+ */
+#define FORCE_UNCHARGE_BATCH (128)
+static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
+ struct mem_cgroup_per_zone *mz,
+ int active)
+{
+ struct page_cgroup *pc;
+ struct page *page;
+ int count = FORCE_UNCHARGE_BATCH;
+ unsigned long flags;
+ struct list_head *list;
+
+ if (active)
+ list = &mz->active_list;
+ else
+ list = &mz->inactive_list;
+
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ while (!list_empty(list)) {
+ pc = list_entry(list->prev, struct page_cgroup, lru);
+ page = pc->page;
+ get_page(page);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+ /*
+ * Check if this page is on LRU. !LRU page can be found
+ * if it's under page migration.
+ */
+ if (PageLRU(page)) {
+ __mem_cgroup_uncharge_common(page,
+ MEM_CGROUP_CHARGE_TYPE_FORCE);
+ put_page(page);
+ if (--count <= 0) {
+ count = FORCE_UNCHARGE_BATCH;
+ cond_resched();
+ }
+ } else
+ cond_resched();
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ }
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+}
+
+/*
+ * make mem_cgroup's charge to be 0 if there is no task.
+ * This enables deleting this mem_cgroup.
+ */
+static int mem_cgroup_force_empty(struct mem_cgroup *mem)
+{
+ int ret = -EBUSY;
+ int node, zid;
+
+ css_get(&mem->css);
/*
- * Round up the value to the closest page size
+ * page reclaim code (kswapd etc..) will move pages between
+ * active_list <-> inactive_list while we don't take a lock.
+ * So, we have to do loop here until all lists are empty.
*/
- *tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT;
+ while (mem->res.usage > 0) {
+ if (atomic_read(&mem->css.cgroup->count) > 0)
+ goto out;
+ for_each_node_state(node, N_POSSIBLE)
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ struct mem_cgroup_per_zone *mz;
+ mz = mem_cgroup_zoneinfo(mem, node, zid);
+ /* drop all page_cgroup in active_list */
+ mem_cgroup_force_empty_list(mem, mz, 1);
+ /* drop all page_cgroup in inactive_list */
+ mem_cgroup_force_empty_list(mem, mz, 0);
+ }
+ }
+ ret = 0;
+out:
+ css_put(&mem->css);
+ return ret;
+}
+
+static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
+{
+ return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res,
+ cft->private);
+}
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
+static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
+ const char *buffer)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ unsigned long long val;
+ int ret;
+
+ switch (cft->private) {
+ case RES_LIMIT:
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (!ret)
+ ret = mem_cgroup_resize_limit(memcg, val);
+ break;
+ default:
+ ret = -EINVAL; /* should be BUG() ? */
+ break;
+ }
+ return ret;
+}
+
+static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
+{
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cont);
+ switch (event) {
+ case RES_MAX_USAGE:
+ res_counter_reset_max(&mem->res);
+ break;
+ case RES_FAILCNT:
+ res_counter_reset_failcnt(&mem->res);
+ break;
+ }
return 0;
}
-static ssize_t mem_cgroup_read(struct cgroup *cont,
- struct cftype *cft, struct file *file,
- char __user *userbuf, size_t nbytes, loff_t *ppos)
+static int mem_force_empty_write(struct cgroup *cont, unsigned int event)
{
- return res_counter_read(&mem_cgroup_from_cont(cont)->res,
- cft->private, userbuf, nbytes, ppos,
- NULL);
+ return mem_cgroup_force_empty(mem_cgroup_from_cont(cont));
}
-static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
- struct file *file, const char __user *userbuf,
- size_t nbytes, loff_t *ppos)
+static const struct mem_cgroup_stat_desc {
+ const char *msg;
+ u64 unit;
+} mem_cgroup_stat_desc[] = {
+ [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
+ [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
+ [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
+ [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
+};
+
+static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
+ struct cgroup_map_cb *cb)
{
- return res_counter_write(&mem_cgroup_from_cont(cont)->res,
- cft->private, userbuf, nbytes, ppos,
- mem_cgroup_write_strategy);
+ struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
+ struct mem_cgroup_stat *stat = &mem_cont->stat;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
+ s64 val;
+
+ val = mem_cgroup_read_stat(stat, i);
+ val *= mem_cgroup_stat_desc[i].unit;
+ cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
+ }
+ /* showing # of active pages */
+ {
+ unsigned long active, inactive;
+
+ inactive = mem_cgroup_get_all_zonestat(mem_cont,
+ MEM_CGROUP_ZSTAT_INACTIVE);
+ active = mem_cgroup_get_all_zonestat(mem_cont,
+ MEM_CGROUP_ZSTAT_ACTIVE);
+ cb->fill(cb, "active", (active) * PAGE_SIZE);
+ cb->fill(cb, "inactive", (inactive) * PAGE_SIZE);
+ }
+ return 0;
}
static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
.private = RES_USAGE,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "max_usage_in_bytes",
+ .private = RES_MAX_USAGE,
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
},
{
.name = "limit_in_bytes",
.private = RES_LIMIT,
- .write = mem_cgroup_write,
- .read = mem_cgroup_read,
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
},
{
.name = "failcnt",
.private = RES_FAILCNT,
- .read = mem_cgroup_read,
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "force_empty",
+ .trigger = mem_force_empty_write,
+ },
+ {
+ .name = "stat",
+ .read_map = mem_control_stat_show,
},
};
-static struct mem_cgroup init_mem_cgroup;
+static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
+{
+ struct mem_cgroup_per_node *pn;
+ struct mem_cgroup_per_zone *mz;
+ int zone, tmp = node;
+ /*
+ * This routine is called against possible nodes.
+ * But it's BUG to call kmalloc() against offline node.
+ *
+ * TODO: this routine can waste much memory for nodes which will
+ * never be onlined. It's better to use memory hotplug callback
+ * function.
+ */
+ if (!node_state(node, N_NORMAL_MEMORY))
+ tmp = -1;
+ pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
+ if (!pn)
+ return 1;
+
+ mem->info.nodeinfo[node] = pn;
+ memset(pn, 0, sizeof(*pn));
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ mz = &pn->zoneinfo[zone];
+ INIT_LIST_HEAD(&mz->active_list);
+ INIT_LIST_HEAD(&mz->inactive_list);
+ spin_lock_init(&mz->lru_lock);
+ }
+ return 0;
+}
+
+static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
+{
+ kfree(mem->info.nodeinfo[node]);
+}
+
+static struct mem_cgroup *mem_cgroup_alloc(void)
+{
+ struct mem_cgroup *mem;
+
+ if (sizeof(*mem) < PAGE_SIZE)
+ mem = kmalloc(sizeof(*mem), GFP_KERNEL);
+ else
+ mem = vmalloc(sizeof(*mem));
+
+ if (mem)
+ memset(mem, 0, sizeof(*mem));
+ return mem;
+}
+
+static void mem_cgroup_free(struct mem_cgroup *mem)
+{
+ if (sizeof(*mem) < PAGE_SIZE)
+ kfree(mem);
+ else
+ vfree(mem);
+}
+
static struct cgroup_subsys_state *
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
{
struct mem_cgroup *mem;
+ int node;
if (unlikely((cont->parent) == NULL)) {
mem = &init_mem_cgroup;
- init_mm.mem_cgroup = mem;
- } else
- mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
-
- if (mem == NULL)
- return NULL;
+ page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC);
+ } else {
+ mem = mem_cgroup_alloc();
+ if (!mem)
+ return ERR_PTR(-ENOMEM);
+ }
res_counter_init(&mem->res);
- INIT_LIST_HEAD(&mem->active_list);
- INIT_LIST_HEAD(&mem->inactive_list);
- spin_lock_init(&mem->lru_lock);
+
+ for_each_node_state(node, N_POSSIBLE)
+ if (alloc_mem_cgroup_per_zone_info(mem, node))
+ goto free_out;
+
return &mem->css;
+free_out:
+ for_each_node_state(node, N_POSSIBLE)
+ free_mem_cgroup_per_zone_info(mem, node);
+ if (cont->parent != NULL)
+ mem_cgroup_free(mem);
+ return ERR_PTR(-ENOMEM);
+}
+
+static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
+ struct cgroup *cont)
+{
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+ mem_cgroup_force_empty(mem);
}
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
struct cgroup *cont)
{
- kfree(mem_cgroup_from_cont(cont));
+ int node;
+ struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+
+ for_each_node_state(node, N_POSSIBLE)
+ free_mem_cgroup_per_zone_info(mem, node);
+
+ mem_cgroup_free(mem_cgroup_from_cont(cont));
}
static int mem_cgroup_populate(struct cgroup_subsys *ss,
mem = mem_cgroup_from_cont(cont);
old_mem = mem_cgroup_from_cont(old_cont);
- if (mem == old_mem)
- goto out;
-
/*
* Only thread group leaders are allowed to migrate, the mm_struct is
* in effect owned by the leader
*/
- if (p->tgid != p->pid)
+ if (!thread_group_leader(p))
goto out;
- css_get(&mem->css);
- rcu_assign_pointer(mm->mem_cgroup, mem);
- css_put(&old_mem->css);
-
out:
mmput(mm);
- return;
}
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,
.populate = mem_cgroup_populate,
.attach = mem_cgroup_move_task,
- .early_init = 1,
+ .early_init = 0,
};