Merge branch 'vhost-net' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[pandora-kernel.git] / mm / ksm.c

diff --git a/mm/ksm.c b/mm/ksm.c
index eb9f680..e2ae004 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -33,6 +33,7 @@
 #include <linux/mmu_notifier.h>
 #include <linux/swap.h>
 #include <linux/ksm.h>
+#include <linux/hash.h>
 
 #include <asm/tlbflush.h>
 #include "internal.h"
@@ -153,8 +154,9 @@ struct rmap_item {
 static struct rb_root root_stable_tree = RB_ROOT;
 static struct rb_root root_unstable_tree = RB_ROOT;
 
-#define MM_SLOTS_HASH_HEADS 1024
-static struct hlist_head *mm_slots_hash;
+#define MM_SLOTS_HASH_SHIFT 10
+#define MM_SLOTS_HASH_HEADS (1 << MM_SLOTS_HASH_SHIFT)
+static struct hlist_head mm_slots_hash[MM_SLOTS_HASH_HEADS];
 
 static struct mm_slot ksm_mm_head = {
        .mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list),
@@ -269,28 +271,13 @@ static inline void free_mm_slot(struct mm_slot *mm_slot)
        kmem_cache_free(mm_slot_cache, mm_slot);
 }
 
-static int __init mm_slots_hash_init(void)
-{
-       mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head),
-                               GFP_KERNEL);
-       if (!mm_slots_hash)
-               return -ENOMEM;
-       return 0;
-}
-
-static void __init mm_slots_hash_free(void)
-{
-       kfree(mm_slots_hash);
-}
-
 static struct mm_slot *get_mm_slot(struct mm_struct *mm)
 {
        struct mm_slot *mm_slot;
        struct hlist_head *bucket;
        struct hlist_node *node;
 
-       bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
-                               % MM_SLOTS_HASH_HEADS];
+       bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
        hlist_for_each_entry(mm_slot, node, bucket, link) {
                if (mm == mm_slot->mm)
                        return mm_slot;
@@ -303,8 +290,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm,
 {
        struct hlist_head *bucket;
 
-       bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
-                               % MM_SLOTS_HASH_HEADS];
+       bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
        mm_slot->mm = mm;
        hlist_add_head(&mm_slot->link, bucket);
 }
@@ -318,19 +304,14 @@ static void hold_anon_vma(struct rmap_item *rmap_item,
                          struct anon_vma *anon_vma)
 {
        rmap_item->anon_vma = anon_vma;
-       atomic_inc(&anon_vma->external_refcount);
+       get_anon_vma(anon_vma);
 }
 
-static void drop_anon_vma(struct rmap_item *rmap_item)
+static void ksm_drop_anon_vma(struct rmap_item *rmap_item)
 {
        struct anon_vma *anon_vma = rmap_item->anon_vma;
 
-       if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->lock)) {
-               int empty = list_empty(&anon_vma->head);
-               anon_vma_unlock(anon_vma);
-               if (empty)
-                       anon_vma_free(anon_vma);
-       }
+       drop_anon_vma(anon_vma);
 }
 
 /*
@@ -415,7 +396,7 @@ static void break_cow(struct rmap_item *rmap_item)
         * It is not an accident that whenever we want to break COW
         * to undo, we also need to drop a reference to the anon_vma.
         */
-       drop_anon_vma(rmap_item);
+       ksm_drop_anon_vma(rmap_item);
 
        down_read(&mm->mmap_sem);
        if (ksm_test_exit(mm))
@@ -470,7 +451,7 @@ static void remove_node_from_stable_tree(struct stable_node *stable_node)
                        ksm_pages_sharing--;
                else
                        ksm_pages_shared--;
-               drop_anon_vma(rmap_item);
+               ksm_drop_anon_vma(rmap_item);
                rmap_item->address &= PAGE_MASK;
                cond_resched();
        }
@@ -558,7 +539,7 @@ static void remove_rmap_item_from_tree(struct rmap_item *rmap_item)
                else
                        ksm_pages_shared--;
 
-               drop_anon_vma(rmap_item);
+               ksm_drop_anon_vma(rmap_item);
                rmap_item->address &= PAGE_MASK;
 
        } else if (rmap_item->address & UNSTABLE_FLAG) {
@@ -1943,15 +1924,11 @@ static int __init ksm_init(void)
        if (err)
                goto out;
 
-       err = mm_slots_hash_init();
-       if (err)
-               goto out_free1;
-
        ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
        if (IS_ERR(ksm_thread)) {
                printk(KERN_ERR "ksm: creating kthread failed\n");
                err = PTR_ERR(ksm_thread);
-               goto out_free2;
+               goto out_free;
        }
 
 #ifdef CONFIG_SYSFS
@@ -1959,7 +1936,7 @@ static int __init ksm_init(void)
        if (err) {
                printk(KERN_ERR "ksm: register sysfs failed\n");
                kthread_stop(ksm_thread);
-               goto out_free2;
+               goto out_free;
        }
 #else
        ksm_run = KSM_RUN_MERGE;        /* no way for user to start it */
@@ -1975,9 +1952,7 @@ static int __init ksm_init(void)
 #endif
        return 0;
 
-out_free2:
-       mm_slots_hash_free();
-out_free1:
+out_free:
        ksm_slab_free();
 out:
        return err;