X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mm%2Fksm.c;h=e2ae00458320786a380a1ab370efe0dc6cfd6e1a;hb=062e27ec1b49d12bdb1ecc94d74b5fee5a5775db;hp=6c3e99b4ae7c0726851ea5281fbb39f90f7b9ea2;hpb=05318bc905467237d4aa68a701f6e92a2b332218;p=firefly-linux-kernel-4.4.55.git diff --git a/mm/ksm.c b/mm/ksm.c index 6c3e99b4ae7c..e2ae00458320 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #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); - spin_unlock(&anon_vma->lock); - 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) { @@ -1566,7 +1547,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1589,7 +1570,7 @@ again: if (!search_new_forks || !mapcount) break; } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); if (!mapcount) goto out; } @@ -1619,7 +1600,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1637,11 +1618,11 @@ again: ret = try_to_unmap_one(page, vma, rmap_item->address, flags); if (ret != SWAP_AGAIN || !page_mapped(page)) { - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); goto out; } } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } if (!search_new_forks++) goto again; @@ -1671,7 +1652,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - spin_lock(&anon_vma->lock); + anon_vma_lock(anon_vma); list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || @@ -1688,11 +1669,11 @@ again: ret = rmap_one(page, vma, rmap_item->address, arg); if (ret != SWAP_AGAIN) { - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); goto out; } } - spin_unlock(&anon_vma->lock); + anon_vma_unlock(anon_vma); } if (!search_new_forks++) goto again; @@ -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;