]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - mm/memcontrol.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6-omap-h63xx.git] / mm / memcontrol.c
index 031682e7ef0c8fbafe2d18ee397925b2335a25af..866dcc7eeb0c3da1e4c6d822ece39a3ea65dc6f9 100644 (file)
 #include <linux/seq_file.h>
 #include <linux/vmalloc.h>
 #include <linux/mm_inline.h>
+#include <linux/page_cgroup.h>
 
 #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
 
 /*
@@ -135,79 +135,6 @@ struct mem_cgroup {
 };
 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 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
-#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
- * page_cgroup helps us identify information about the cgroup
- */
-struct page_cgroup {
-       struct list_head lru;           /* per cgroup LRU list */
-       struct page *page;
-       struct mem_cgroup *mem_cgroup;
-       unsigned long flags;
-};
-
-enum {
-       /* flags for mem_cgroup */
-       PCG_CACHE, /* charged as cache */
-       /* flags for LRU placement */
-       PCG_ACTIVE, /* page is active in this cgroup */
-       PCG_FILE, /* page is file system backed */
-       PCG_UNEVICTABLE, /* page is unevictableable */
-};
-
-#define TESTPCGFLAG(uname, lname)                      \
-static inline int PageCgroup##uname(struct page_cgroup *pc)    \
-       { return test_bit(PCG_##lname, &pc->flags); }
-
-#define SETPCGFLAG(uname, lname)                       \
-static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
-       { set_bit(PCG_##lname, &pc->flags);  }
-
-#define CLEARPCGFLAG(uname, lname)                     \
-static inline void ClearPageCgroup##uname(struct page_cgroup *pc)      \
-       { clear_bit(PCG_##lname, &pc->flags);  }
-
-
-/* Cache flag is set only once (at allocation) */
-TESTPCGFLAG(Cache, CACHE)
-
-/* LRU management flags (from global-lru definition) */
-TESTPCGFLAG(File, FILE)
-SETPCGFLAG(File, FILE)
-CLEARPCGFLAG(File, FILE)
-
-TESTPCGFLAG(Active, ACTIVE)
-SETPCGFLAG(Active, ACTIVE)
-CLEARPCGFLAG(Active, ACTIVE)
-
-TESTPCGFLAG(Unevictable, UNEVICTABLE)
-SETPCGFLAG(Unevictable, UNEVICTABLE)
-CLEARPCGFLAG(Unevictable, UNEVICTABLE)
-
-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,
@@ -216,12 +143,18 @@ enum charge_type {
        NR_CHARGE_TYPE,
 };
 
+/* only for here (for easy reading.) */
+#define PCGF_CACHE     (1UL << PCG_CACHE)
+#define PCGF_USED      (1UL << PCG_USED)
+#define PCGF_ACTIVE    (1UL << PCG_ACTIVE)
+#define PCGF_LOCK      (1UL << PCG_LOCK)
+#define PCGF_FILE      (1UL << PCG_FILE)
 static const unsigned long
 pcg_default_flags[NR_CHARGE_TYPE] = {
-       ((1 << PCG_CACHE) | (1 << PCG_FILE)),
-       ((1 << PCG_ACTIVE)),
-       ((1 << PCG_ACTIVE) | (1 << PCG_CACHE)),
-       0,
+       PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */
+       PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */
+       PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
+       0, /* FORCE */
 };
 
 /*
@@ -303,37 +236,6 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
                                struct mem_cgroup, css);
 }
 
-static inline int page_cgroup_locked(struct page *page)
-{
-       return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
-{
-       VM_BUG_ON(!page_cgroup_locked(page));
-       page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK);
-}
-
-struct page_cgroup *page_get_page_cgroup(struct page *page)
-{
-       return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK);
-}
-
-static void lock_page_cgroup(struct page *page)
-{
-       bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static int try_lock_page_cgroup(struct page *page)
-{
-       return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static void unlock_page_cgroup(struct page *page)
-{
-       bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
 static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
                        struct page_cgroup *pc)
 {
@@ -436,17 +338,16 @@ void mem_cgroup_move_lists(struct page *page, enum lru_list lru)
         * 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))
+       pc = lookup_page_cgroup(page);
+       if (!trylock_page_cgroup(pc))
                return;
-
-       pc = page_get_page_cgroup(page);
-       if (pc) {
+       if (pc && PageCgroupUsed(pc)) {
                mz = page_cgroup_zoneinfo(pc);
                spin_lock_irqsave(&mz->lru_lock, flags);
                __mem_cgroup_move_lists(pc, lru);
                spin_unlock_irqrestore(&mz->lru_lock, flags);
        }
-       unlock_page_cgroup(page);
+       unlock_page_cgroup(pc);
 }
 
 /*
@@ -533,6 +434,8 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
        list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
                if (scan >= nr_to_scan)
                        break;
+               if (unlikely(!PageCgroupUsed(pc)))
+                       continue;
                page = pc->page;
 
                if (unlikely(!PageLRU(page)))
@@ -576,26 +479,27 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
 {
        struct mem_cgroup *mem;
        struct page_cgroup *pc;
-       unsigned long flags;
        unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
        struct mem_cgroup_per_zone *mz;
+       unsigned long flags;
 
-       pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
-       if (unlikely(pc == NULL))
-               goto err;
-
+       pc = lookup_page_cgroup(page);
+       /* can happen at boot */
+       if (unlikely(!pc))
+               return 0;
+       prefetchw(pc);
        /*
         * 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 (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;
                }
                /*
@@ -631,36 +535,33 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
                }
        }
 
+
+       lock_page_cgroup(pc);
+       if (unlikely(PageCgroupUsed(pc))) {
+               unlock_page_cgroup(pc);
+               res_counter_uncharge(&mem->res, PAGE_SIZE);
+               css_put(&mem->css);
+
+               goto done;
+       }
        pc->mem_cgroup = mem;
-       pc->page = page;
        /*
         * If a page is accounted as a page cache, insert to inactive list.
         * If anon, insert to active list.
         */
        pc->flags = pcg_default_flags[ctype];
 
-       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;
-       }
-       page_assign_page_cgroup(page, pc);
-
        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);
+       unlock_page_cgroup(pc);
 
-       unlock_page_cgroup(page);
 done:
        return 0;
 out:
        css_put(&mem->css);
-       kmem_cache_free(page_cgroup_cache, pc);
-err:
        return -ENOMEM;
 }
 
@@ -668,7 +569,8 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
 {
        if (mem_cgroup_subsys.disabled)
                return 0;
-
+       if (PageCompound(page))
+               return 0;
        /*
         * If already mapped, we don't have to account.
         * If page cache, page->mapping has address_space.
@@ -689,7 +591,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 {
        if (mem_cgroup_subsys.disabled)
                return 0;
-
+       if (PageCompound(page))
+               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
@@ -702,15 +605,16 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
        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);
+
+               pc = lookup_page_cgroup(page);
+               if (!pc)
+                       return 0;
+               lock_page_cgroup(pc);
+               if (PageCgroupUsed(pc)) {
+                       unlock_page_cgroup(pc);
                        return 0;
                }
-               unlock_page_cgroup(page);
+               unlock_page_cgroup(pc);
        }
 
        if (unlikely(!mm))
@@ -741,37 +645,39 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
        /*
         * 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);
+       pc = lookup_page_cgroup(page);
+       if (unlikely(!pc || !PageCgroupUsed(pc)))
+               return;
 
-       if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
-           && ((PageCgroupCache(pc) || page_mapped(page))))
-               goto unlock;
+       lock_page_cgroup(pc);
+       if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED && page_mapped(page))
+            || !PageCgroupUsed(pc)) {
+               /* This happens at race in zap_pte_range() and do_swap_page()*/
+               unlock_page_cgroup(pc);
+               return;
+       }
+       ClearPageCgroupUsed(pc);
+       mem = pc->mem_cgroup;
 
        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);
+       unlock_page_cgroup(pc);
 
-       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)
 {
+       /* early check. */
+       if (page_mapped(page))
+               return;
+       if (page->mapping && !PageAnon(page))
+               return;
        __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
@@ -795,9 +701,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
        if (mem_cgroup_subsys.disabled)
                return 0;
 
-       lock_page_cgroup(page);
-       pc = page_get_page_cgroup(page);
-       if (pc) {
+       pc = lookup_page_cgroup(page);
+       lock_page_cgroup(pc);
+       if (PageCgroupUsed(pc)) {
                mem = pc->mem_cgroup;
                css_get(&mem->css);
                if (PageCgroupCache(pc)) {
@@ -807,7 +713,7 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
                                ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
                }
        }
-       unlock_page_cgroup(page);
+       unlock_page_cgroup(pc);
        if (mem) {
                ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
                        ctype, mem);
@@ -832,7 +738,7 @@ void mem_cgroup_end_migration(struct page *newpage)
         */
        if (!newpage->mapping)
                __mem_cgroup_uncharge_common(newpage,
-                                        MEM_CGROUP_CHARGE_TYPE_FORCE);
+                               MEM_CGROUP_CHARGE_TYPE_FORCE);
        else if (PageAnon(newpage))
                mem_cgroup_uncharge_page(newpage);
 }
@@ -918,6 +824,8 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
        while (!list_empty(list)) {
                pc = list_entry(list->prev, struct page_cgroup, lru);
                page = pc->page;
+               if (!PageCgroupUsed(pc))
+                       break;
                get_page(page);
                spin_unlock_irqrestore(&mz->lru_lock, flags);
                /*
@@ -932,8 +840,10 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
                                count = FORCE_UNCHARGE_BATCH;
                                cond_resched();
                        }
-               } else
-                       cond_resched();
+               } else {
+                       spin_lock_irqsave(&mz->lru_lock, flags);
+                       break;
+               }
                spin_lock_irqsave(&mz->lru_lock, flags);
        }
        spin_unlock_irqrestore(&mz->lru_lock, flags);
@@ -957,6 +867,8 @@ static int mem_cgroup_force_empty(struct mem_cgroup *mem)
        while (mem->res.usage > 0) {
                if (atomic_read(&mem->css.cgroup->count) > 0)
                        goto out;
+               /* This is for making all *used* pages to be on LRU. */
+               lru_add_drain_all();
                for_each_node_state(node, N_POSSIBLE)
                        for (zid = 0; zid < MAX_NR_ZONES; zid++) {
                                struct mem_cgroup_per_zone *mz;
@@ -965,6 +877,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *mem)
                                for_each_lru(l)
                                        mem_cgroup_force_empty_list(mem, mz, l);
                        }
+               cond_resched();
        }
        ret = 0;
 out:
@@ -1176,7 +1089,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 
        if (unlikely((cont->parent) == NULL)) {
                mem = &init_mem_cgroup;
-               page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC);
        } else {
                mem = mem_cgroup_alloc();
                if (!mem)