mm: add FOLL_MLOCK follow_page flag.
[linux-2.6.git] / mm / page_cgroup.c
index f59d797..5bffada 100644 (file)
@@ -8,6 +8,8 @@
 #include <linux/memory.h>
 #include <linux/vmalloc.h>
 #include <linux/cgroup.h>
+#include <linux/swapops.h>
+#include <linux/kmemleak.h>
 
 static void __meminit
 __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
@@ -15,13 +17,14 @@ __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
        pc->flags = 0;
        pc->mem_cgroup = NULL;
        pc->page = pfn_to_page(pfn);
+       INIT_LIST_HEAD(&pc->lru);
 }
 static unsigned long total_usage;
 
 #if !defined(CONFIG_SPARSEMEM)
 
 
-void __init pgdat_page_cgroup_init(struct pglist_data *pgdat)
+void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 {
        pgdat->node_page_cgroup = NULL;
 }
@@ -49,6 +52,9 @@ static int __init alloc_node_page_cgroup(int nid)
        start_pfn = NODE_DATA(nid)->node_start_pfn;
        nr_pages = NODE_DATA(nid)->node_spanned_pages;
 
+       if (!nr_pages)
+               return 0;
+
        table_size = sizeof(struct page_cgroup) * nr_pages;
 
        base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
@@ -64,12 +70,12 @@ static int __init alloc_node_page_cgroup(int nid)
        return 0;
 }
 
-void __init page_cgroup_init(void)
+void __init page_cgroup_init_flatmem(void)
 {
 
        int nid, fail;
 
-       if (mem_cgroup_subsys.disabled)
+       if (mem_cgroup_disabled())
                return;
 
        for_each_online_node(nid)  {
@@ -78,12 +84,12 @@ void __init page_cgroup_init(void)
                        goto fail;
        }
        printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
-       printk(KERN_INFO "please try cgroup_disable=memory option if you"
-       " don't want\n");
+       printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
+       " don't want memory cgroups\n");
        return;
 fail:
-       printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
-       printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
+       printk(KERN_CRIT "allocation of page_cgroup failed.\n");
+       printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
        panic("Out of memory");
 }
 
@@ -94,31 +100,50 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
        unsigned long pfn = page_to_pfn(page);
        struct mem_section *section = __pfn_to_section(pfn);
 
+       if (!section->page_cgroup)
+               return NULL;
        return section->page_cgroup + pfn;
 }
 
-int __meminit init_section_page_cgroup(unsigned long pfn)
+/* __alloc_bootmem...() is protected by !slab_available() */
+static int __init_refok init_section_page_cgroup(unsigned long pfn)
 {
-       struct mem_section *section;
+       struct mem_section *section = __pfn_to_section(pfn);
        struct page_cgroup *base, *pc;
        unsigned long table_size;
        int nid, index;
 
-       section = __pfn_to_section(pfn);
-
-       if (section->page_cgroup)
-               return 0;
-
-       nid = page_to_nid(pfn_to_page(pfn));
-
-       table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
-       if (slab_is_available()) {
-               base = kmalloc_node(table_size, GFP_KERNEL, nid);
-               if (!base)
-                       base = vmalloc_node(table_size, nid);
+       if (!section->page_cgroup) {
+               nid = page_to_nid(pfn_to_page(pfn));
+               table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+               VM_BUG_ON(!slab_is_available());
+               if (node_state(nid, N_HIGH_MEMORY)) {
+                       base = kmalloc_node(table_size,
+                               GFP_KERNEL | __GFP_NOWARN, nid);
+                       if (!base)
+                               base = vmalloc_node(table_size, nid);
+               } else {
+                       base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
+                       if (!base)
+                               base = vmalloc(table_size);
+               }
+               /*
+                * The value stored in section->page_cgroup is (base - pfn)
+                * and it does not point to the memory block allocated above,
+                * causing kmemleak false positives.
+                */
+               kmemleak_not_leak(base);
        } else {
-               base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), table_size,
-                               PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+               /*
+                * We don't have to allocate page_cgroup again, but
+                * address of memmap may be changed. So, we have to initialize
+                * again.
+                */
+               base = section->page_cgroup + pfn;
+               table_size = 0;
+               /* check address of memmap is changed or not. */
+               if (base->page == pfn_to_page(pfn))
+                       return 0;
        }
 
        if (!base) {
@@ -131,7 +156,6 @@ int __meminit init_section_page_cgroup(unsigned long pfn)
                __init_page_cgroup(pc, pfn + index);
        }
 
-       section = __pfn_to_section(pfn);
        section->page_cgroup = base - pfn;
        total_usage += table_size;
        return 0;
@@ -158,14 +182,14 @@ void __free_page_cgroup(unsigned long pfn)
        }
 }
 
-int online_page_cgroup(unsigned long start_pfn,
+int __meminit online_page_cgroup(unsigned long start_pfn,
                        unsigned long nr_pages,
                        int nid)
 {
        unsigned long start, end, pfn;
        int fail = 0;
 
-       start = start_pfn & (PAGES_PER_SECTION - 1);
+       start = start_pfn & ~(PAGES_PER_SECTION - 1);
        end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 
        for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
@@ -183,12 +207,12 @@ int online_page_cgroup(unsigned long start_pfn,
        return -ENOMEM;
 }
 
-int offline_page_cgroup(unsigned long start_pfn,
+int __meminit offline_page_cgroup(unsigned long start_pfn,
                unsigned long nr_pages, int nid)
 {
        unsigned long start, end, pfn;
 
-       start = start_pfn & (PAGES_PER_SECTION - 1);
+       start = start_pfn & ~(PAGES_PER_SECTION - 1);
        end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 
        for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
@@ -197,7 +221,7 @@ int offline_page_cgroup(unsigned long start_pfn,
 
 }
 
-static int page_cgroup_callback(struct notifier_block *self,
+static int __meminit page_cgroup_callback(struct notifier_block *self,
                               unsigned long action, void *arg)
 {
        struct memory_notify *mn = arg;
@@ -207,18 +231,23 @@ static int page_cgroup_callback(struct notifier_block *self,
                ret = online_page_cgroup(mn->start_pfn,
                                   mn->nr_pages, mn->status_change_nid);
                break;
-       case MEM_CANCEL_ONLINE:
        case MEM_OFFLINE:
                offline_page_cgroup(mn->start_pfn,
                                mn->nr_pages, mn->status_change_nid);
                break;
+       case MEM_CANCEL_ONLINE:
        case MEM_GOING_OFFLINE:
                break;
        case MEM_ONLINE:
        case MEM_CANCEL_OFFLINE:
                break;
        }
-       ret = notifier_from_errno(ret);
+
+       if (ret)
+               ret = notifier_from_errno(ret);
+       else
+               ret = NOTIFY_OK;
+
        return ret;
 }
 
@@ -229,7 +258,7 @@ void __init page_cgroup_init(void)
        unsigned long pfn;
        int fail = 0;
 
-       if (mem_cgroup_subsys.disabled)
+       if (mem_cgroup_disabled())
                return;
 
        for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
@@ -238,19 +267,238 @@ void __init page_cgroup_init(void)
                fail = init_section_page_cgroup(pfn);
        }
        if (fail) {
-               printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
+               printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
                panic("Out of memory");
        } else {
                hotplug_memory_notifier(page_cgroup_callback, 0);
        }
        printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
-       printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
-       " want\n");
+       printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
+       " want memory cgroups\n");
 }
 
-void __init pgdat_page_cgroup_init(struct pglist_data *pgdat)
+void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 {
        return;
 }
 
 #endif
+
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+
+static DEFINE_MUTEX(swap_cgroup_mutex);
+struct swap_cgroup_ctrl {
+       struct page **map;
+       unsigned long length;
+       spinlock_t      lock;
+};
+
+struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
+
+struct swap_cgroup {
+       unsigned short          id;
+};
+#define SC_PER_PAGE    (PAGE_SIZE/sizeof(struct swap_cgroup))
+#define SC_POS_MASK    (SC_PER_PAGE - 1)
+
+/*
+ * SwapCgroup implements "lookup" and "exchange" operations.
+ * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
+ * against SwapCache. At swap_free(), this is accessed directly from swap.
+ *
+ * This means,
+ *  - we have no race in "exchange" when we're accessed via SwapCache because
+ *    SwapCache(and its swp_entry) is under lock.
+ *  - When called via swap_free(), there is no user of this entry and no race.
+ * Then, we don't need lock around "exchange".
+ *
+ * TODO: we can push these buffers out to HIGHMEM.
+ */
+
+/*
+ * allocate buffer for swap_cgroup.
+ */
+static int swap_cgroup_prepare(int type)
+{
+       struct page *page;
+       struct swap_cgroup_ctrl *ctrl;
+       unsigned long idx, max;
+
+       ctrl = &swap_cgroup_ctrl[type];
+
+       for (idx = 0; idx < ctrl->length; idx++) {
+               page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+               if (!page)
+                       goto not_enough_page;
+               ctrl->map[idx] = page;
+       }
+       return 0;
+not_enough_page:
+       max = idx;
+       for (idx = 0; idx < max; idx++)
+               __free_page(ctrl->map[idx]);
+
+       return -ENOMEM;
+}
+
+/**
+ * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
+ * @end: swap entry to be cmpxchged
+ * @old: old id
+ * @new: new id
+ *
+ * Returns old id at success, 0 at failure.
+ * (There is no mem_cgroup useing 0 as its id)
+ */
+unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
+                                       unsigned short old, unsigned short new)
+{
+       int type = swp_type(ent);
+       unsigned long offset = swp_offset(ent);
+       unsigned long idx = offset / SC_PER_PAGE;
+       unsigned long pos = offset & SC_POS_MASK;
+       struct swap_cgroup_ctrl *ctrl;
+       struct page *mappage;
+       struct swap_cgroup *sc;
+       unsigned long flags;
+       unsigned short retval;
+
+       ctrl = &swap_cgroup_ctrl[type];
+
+       mappage = ctrl->map[idx];
+       sc = page_address(mappage);
+       sc += pos;
+       spin_lock_irqsave(&ctrl->lock, flags);
+       retval = sc->id;
+       if (retval == old)
+               sc->id = new;
+       else
+               retval = 0;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
+       return retval;
+}
+
+/**
+ * swap_cgroup_record - record mem_cgroup for this swp_entry.
+ * @ent: swap entry to be recorded into
+ * @mem: mem_cgroup to be recorded
+ *
+ * Returns old value at success, 0 at failure.
+ * (Of course, old value can be 0.)
+ */
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+{
+       int type = swp_type(ent);
+       unsigned long offset = swp_offset(ent);
+       unsigned long idx = offset / SC_PER_PAGE;
+       unsigned long pos = offset & SC_POS_MASK;
+       struct swap_cgroup_ctrl *ctrl;
+       struct page *mappage;
+       struct swap_cgroup *sc;
+       unsigned short old;
+       unsigned long flags;
+
+       ctrl = &swap_cgroup_ctrl[type];
+
+       mappage = ctrl->map[idx];
+       sc = page_address(mappage);
+       sc += pos;
+       spin_lock_irqsave(&ctrl->lock, flags);
+       old = sc->id;
+       sc->id = id;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
+
+       return old;
+}
+
+/**
+ * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
+ * @ent: swap entry to be looked up.
+ *
+ * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
+ */
+unsigned short lookup_swap_cgroup(swp_entry_t ent)
+{
+       int type = swp_type(ent);
+       unsigned long offset = swp_offset(ent);
+       unsigned long idx = offset / SC_PER_PAGE;
+       unsigned long pos = offset & SC_POS_MASK;
+       struct swap_cgroup_ctrl *ctrl;
+       struct page *mappage;
+       struct swap_cgroup *sc;
+       unsigned short ret;
+
+       ctrl = &swap_cgroup_ctrl[type];
+       mappage = ctrl->map[idx];
+       sc = page_address(mappage);
+       sc += pos;
+       ret = sc->id;
+       return ret;
+}
+
+int swap_cgroup_swapon(int type, unsigned long max_pages)
+{
+       void *array;
+       unsigned long array_size;
+       unsigned long length;
+       struct swap_cgroup_ctrl *ctrl;
+
+       if (!do_swap_account)
+               return 0;
+
+       length = ((max_pages/SC_PER_PAGE) + 1);
+       array_size = length * sizeof(void *);
+
+       array = vmalloc(array_size);
+       if (!array)
+               goto nomem;
+
+       memset(array, 0, array_size);
+       ctrl = &swap_cgroup_ctrl[type];
+       mutex_lock(&swap_cgroup_mutex);
+       ctrl->length = length;
+       ctrl->map = array;
+       spin_lock_init(&ctrl->lock);
+       if (swap_cgroup_prepare(type)) {
+               /* memory shortage */
+               ctrl->map = NULL;
+               ctrl->length = 0;
+               vfree(array);
+               mutex_unlock(&swap_cgroup_mutex);
+               goto nomem;
+       }
+       mutex_unlock(&swap_cgroup_mutex);
+
+       return 0;
+nomem:
+       printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
+       printk(KERN_INFO
+               "swap_cgroup can be disabled by noswapaccount boot option\n");
+       return -ENOMEM;
+}
+
+void swap_cgroup_swapoff(int type)
+{
+       int i;
+       struct swap_cgroup_ctrl *ctrl;
+
+       if (!do_swap_account)
+               return;
+
+       mutex_lock(&swap_cgroup_mutex);
+       ctrl = &swap_cgroup_ctrl[type];
+       if (ctrl->map) {
+               for (i = 0; i < ctrl->length; i++) {
+                       struct page *page = ctrl->map[i];
+                       if (page)
+                               __free_page(page);
+               }
+               vfree(ctrl->map);
+               ctrl->map = NULL;
+               ctrl->length = 0;
+       }
+       mutex_unlock(&swap_cgroup_mutex);
+}
+
+#endif