[PATCH 11/17] lib/interval_tree: fast overlap detection

Michael S. Tsirkin mst at redhat.com
Tue Aug 1 17:16:37 UTC 2017


On Tue, Jul 18, 2017 at 06:45:57PM -0700, Davidlohr Bueso wrote:
> Allow interval trees to quickly check for overlaps to avoid
> unnecesary tree lookups in interval_tree_iter_first().
> 
> As of this patch, all interval tree flavors will require
> using a 'rb_root_cached' such that we can have the leftmost
> node easily available. While most users will make use of this
> feature, those with special functions (in addition to the generic
> insert, delete, search calls) will avoid using the cached
> option as they can do funky things with insertions -- for example,
> vma_interval_tree_insert_after().
> 
> Cc: David Airlie <airlied at linux.ie>
> Cc: dri-devel at lists.freedesktop.org
> Cc: "Michael S. Tsirkin" <mst at redhat.com>
> Cc: Jason Wang <jasowang at redhat.com>
> Cc: Doug Ledford <dledford at redhat.com>
> Cc: Christian Benvenuti <benve at cisco.com>
> Cc: linux-rdma at vger.kernel.org
> Acked-by: Christian König <christian.koenig at amd.com>
> Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>
> Signed-off-by: Davidlohr Bueso <dbueso at suse.de>

For vhost bits:

Acked-by: Michael S. Tsirkin <mst at redhat.com>


> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c             |  8 ++--
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c             |  7 ++--
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h             |  2 +-
>  drivers/gpu/drm/drm_mm.c                           | 19 +++++----
>  drivers/gpu/drm/drm_vma_manager.c                  |  2 +-
>  drivers/gpu/drm/i915/i915_gem_userptr.c            |  6 +--
>  drivers/gpu/drm/radeon/radeon.h                    |  2 +-
>  drivers/gpu/drm/radeon/radeon_mn.c                 |  8 ++--
>  drivers/gpu/drm/radeon/radeon_vm.c                 |  7 ++--
>  drivers/infiniband/core/umem_rbtree.c              |  4 +-
>  drivers/infiniband/core/uverbs_cmd.c               |  2 +-
>  drivers/infiniband/hw/hfi1/mmu_rb.c                | 10 ++---
>  drivers/infiniband/hw/usnic/usnic_uiom.c           |  6 +--
>  drivers/infiniband/hw/usnic/usnic_uiom.h           |  2 +-
>  .../infiniband/hw/usnic/usnic_uiom_interval_tree.c | 15 +++----
>  .../infiniband/hw/usnic/usnic_uiom_interval_tree.h | 12 +++---
>  drivers/vhost/vhost.c                              |  2 +-
>  drivers/vhost/vhost.h                              |  2 +-
>  fs/hugetlbfs/inode.c                               |  6 +--
>  fs/inode.c                                         |  2 +-
>  include/drm/drm_mm.h                               |  2 +-
>  include/linux/fs.h                                 |  4 +-
>  include/linux/interval_tree.h                      |  8 ++--
>  include/linux/interval_tree_generic.h              | 46 +++++++++++++++++-----
>  include/linux/mm.h                                 | 17 ++++----
>  include/linux/rmap.h                               |  4 +-
>  include/rdma/ib_umem_odp.h                         | 11 ++++--
>  include/rdma/ib_verbs.h                            |  2 +-
>  lib/interval_tree_test.c                           |  4 +-
>  mm/interval_tree.c                                 | 10 ++---
>  mm/memory.c                                        |  4 +-
>  mm/mmap.c                                          | 10 ++---
>  mm/rmap.c                                          |  4 +-
>  33 files changed, 145 insertions(+), 105 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> index 38f739fb727b..3f8aef21b9a6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> @@ -51,7 +51,7 @@ struct amdgpu_mn {
>  
>  	/* objects protected by lock */
>  	struct mutex		lock;
> -	struct rb_root		objects;
> +	struct rb_root_cached	objects;
>  };
>  
>  struct amdgpu_mn_node {
> @@ -76,8 +76,8 @@ static void amdgpu_mn_destroy(struct work_struct *work)
>  	mutex_lock(&adev->mn_lock);
>  	mutex_lock(&rmn->lock);
>  	hash_del(&rmn->node);
> -	rbtree_postorder_for_each_entry_safe(node, next_node, &rmn->objects,
> -					     it.rb) {
> +	rbtree_postorder_for_each_entry_safe(node, next_node,
> +					     &rmn->objects.rb_root, it.rb) {
>  		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
>  			bo->mn = NULL;
>  			list_del_init(&bo->mn_list);
> @@ -252,7 +252,7 @@ static struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev)
>  	rmn->mm = mm;
>  	rmn->mn.ops = &amdgpu_mn_ops;
>  	mutex_init(&rmn->lock);
> -	rmn->objects = RB_ROOT;
> +	rmn->objects = RB_ROOT_CACHED;
>  
>  	r = __mmu_notifier_register(&rmn->mn, mm);
>  	if (r)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 5795f81369f0..f872e2179bbd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -2405,7 +2405,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>  	int r, i;
>  	u64 flags;
>  
> -	vm->va = RB_ROOT;
> +	vm->va = RB_ROOT_CACHED;
>  	vm->client_id = atomic64_inc_return(&adev->vm_manager.client_counter);
>  	for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
>  		vm->reserved_vmid[i] = NULL;
> @@ -2512,10 +2512,11 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>  
>  	amd_sched_entity_fini(vm->entity.sched, &vm->entity);
>  
> -	if (!RB_EMPTY_ROOT(&vm->va)) {
> +	if (!RB_EMPTY_ROOT(&vm->va.rb_root)) {
>  		dev_err(adev->dev, "still active bo inside vm\n");
>  	}
> -	rbtree_postorder_for_each_entry_safe(mapping, tmp, &vm->va, rb) {
> +	rbtree_postorder_for_each_entry_safe(mapping, tmp,
> +					     &vm->va.rb_root, rb) {
>  		list_del(&mapping->list);
>  		amdgpu_vm_it_remove(mapping, &vm->va);
>  		kfree(mapping);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 936f158bc5ec..ebffc1253f85 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -106,7 +106,7 @@ struct amdgpu_vm_pt {
>  
>  struct amdgpu_vm {
>  	/* tree of virtual addresses mapped */
> -	struct rb_root		va;
> +	struct rb_root_cached	va;
>  
>  	/* protecting invalidated */
>  	spinlock_t		status_lock;
> diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
> index f794089d30ac..61a1c8ea74bc 100644
> --- a/drivers/gpu/drm/drm_mm.c
> +++ b/drivers/gpu/drm/drm_mm.c
> @@ -169,7 +169,7 @@ INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
>  struct drm_mm_node *
>  __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last)
>  {
> -	return drm_mm_interval_tree_iter_first((struct rb_root *)&mm->interval_tree,
> +	return drm_mm_interval_tree_iter_first((struct rb_root_cached *)&mm->interval_tree,
>  					       start, last) ?: (struct drm_mm_node *)&mm->head_node;
>  }
>  EXPORT_SYMBOL(__drm_mm_interval_first);
> @@ -180,6 +180,7 @@ static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node,
>  	struct drm_mm *mm = hole_node->mm;
>  	struct rb_node **link, *rb;
>  	struct drm_mm_node *parent;
> +	bool leftmost = true;
>  
>  	node->__subtree_last = LAST(node);
>  
> @@ -196,9 +197,10 @@ static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node,
>  
>  		rb = &hole_node->rb;
>  		link = &hole_node->rb.rb_right;
> +		leftmost = false;
>  	} else {
>  		rb = NULL;
> -		link = &mm->interval_tree.rb_node;
> +		link = &mm->interval_tree.rb_root.rb_node;
>  	}
>  
>  	while (*link) {
> @@ -208,14 +210,15 @@ static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node,
>  			parent->__subtree_last = node->__subtree_last;
>  		if (node->start < parent->start)
>  			link = &parent->rb.rb_left;
> -		else
> +		else {
>  			link = &parent->rb.rb_right;
> +			leftmost = true;
> +		}
>  	}
>  
>  	rb_link_node(&node->rb, rb, link);
> -	rb_insert_augmented(&node->rb,
> -			    &mm->interval_tree,
> -			    &drm_mm_interval_tree_augment);
> +	rb_insert_augmented_cached(&node->rb, &mm->interval_tree, leftmost,
> +				   &drm_mm_interval_tree_augment);
>  }
>  
>  #define RB_INSERT(root, member, expr) do { \
> @@ -577,7 +580,7 @@ void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
>  	*new = *old;
>  
>  	list_replace(&old->node_list, &new->node_list);
> -	rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree);
> +	rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree.rb_root);
>  
>  	if (drm_mm_hole_follows(old)) {
>  		list_replace(&old->hole_stack, &new->hole_stack);
> @@ -863,7 +866,7 @@ void drm_mm_init(struct drm_mm *mm, u64 start, u64 size)
>  	mm->color_adjust = NULL;
>  
>  	INIT_LIST_HEAD(&mm->hole_stack);
> -	mm->interval_tree = RB_ROOT;
> +	mm->interval_tree = RB_ROOT_CACHED;
>  	mm->holes_size = RB_ROOT;
>  	mm->holes_addr = RB_ROOT;
>  
> diff --git a/drivers/gpu/drm/drm_vma_manager.c b/drivers/gpu/drm/drm_vma_manager.c
> index d9100b565198..28f1226576f8 100644
> --- a/drivers/gpu/drm/drm_vma_manager.c
> +++ b/drivers/gpu/drm/drm_vma_manager.c
> @@ -147,7 +147,7 @@ struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_m
>  	struct rb_node *iter;
>  	unsigned long offset;
>  
> -	iter = mgr->vm_addr_space_mm.interval_tree.rb_node;
> +	iter = mgr->vm_addr_space_mm.interval_tree.rb_root.rb_node;
>  	best = NULL;
>  
>  	while (likely(iter)) {
> diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
> index ccd09e8419f5..71dddf66baaa 100644
> --- a/drivers/gpu/drm/i915/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
> @@ -49,7 +49,7 @@ struct i915_mmu_notifier {
>  	spinlock_t lock;
>  	struct hlist_node node;
>  	struct mmu_notifier mn;
> -	struct rb_root objects;
> +	struct rb_root_cached objects;
>  	struct workqueue_struct *wq;
>  };
>  
> @@ -123,7 +123,7 @@ static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
>  	struct interval_tree_node *it;
>  	LIST_HEAD(cancelled);
>  
> -	if (RB_EMPTY_ROOT(&mn->objects))
> +	if (RB_EMPTY_ROOT(&mn->objects.rb_root))
>  		return;
>  
>  	/* interval ranges are inclusive, but invalidate range is exclusive */
> @@ -172,7 +172,7 @@ i915_mmu_notifier_create(struct mm_struct *mm)
>  
>  	spin_lock_init(&mn->lock);
>  	mn->mn.ops = &i915_gem_userptr_notifier;
> -	mn->objects = RB_ROOT;
> +	mn->objects = RB_ROOT_CACHED;
>  	mn->wq = alloc_workqueue("i915-userptr-release", WQ_UNBOUND, 0);
>  	if (mn->wq == NULL) {
>  		kfree(mn);
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 5008f3d4cccc..10d0dd146808 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -924,7 +924,7 @@ struct radeon_vm_id {
>  struct radeon_vm {
>  	struct mutex		mutex;
>  
> -	struct rb_root		va;
> +	struct rb_root_cached	va;
>  
>  	/* protecting invalidated and freed */
>  	spinlock_t		status_lock;
> diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c
> index 896f2cf51e4e..1d62288b7ee3 100644
> --- a/drivers/gpu/drm/radeon/radeon_mn.c
> +++ b/drivers/gpu/drm/radeon/radeon_mn.c
> @@ -50,7 +50,7 @@ struct radeon_mn {
>  
>  	/* objects protected by lock */
>  	struct mutex		lock;
> -	struct rb_root		objects;
> +	struct rb_root_cached	objects;
>  };
>  
>  struct radeon_mn_node {
> @@ -75,8 +75,8 @@ static void radeon_mn_destroy(struct work_struct *work)
>  	mutex_lock(&rdev->mn_lock);
>  	mutex_lock(&rmn->lock);
>  	hash_del(&rmn->node);
> -	rbtree_postorder_for_each_entry_safe(node, next_node, &rmn->objects,
> -					     it.rb) {
> +	rbtree_postorder_for_each_entry_safe(node, next_node,
> +					     &rmn->objects.rb_root, it.rb) {
>  
>  		interval_tree_remove(&node->it, &rmn->objects);
>  		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
> @@ -205,7 +205,7 @@ static struct radeon_mn *radeon_mn_get(struct radeon_device *rdev)
>  	rmn->mm = mm;
>  	rmn->mn.ops = &radeon_mn_ops;
>  	mutex_init(&rmn->lock);
> -	rmn->objects = RB_ROOT;
> +	rmn->objects = RB_ROOT_CACHED;
>  	
>  	r = __mmu_notifier_register(&rmn->mn, mm);
>  	if (r)
> diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
> index 5f68245579a3..f44777a6c2e8 100644
> --- a/drivers/gpu/drm/radeon/radeon_vm.c
> +++ b/drivers/gpu/drm/radeon/radeon_vm.c
> @@ -1185,7 +1185,7 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
>  		vm->ids[i].last_id_use = NULL;
>  	}
>  	mutex_init(&vm->mutex);
> -	vm->va = RB_ROOT;
> +	vm->va = RB_ROOT_CACHED;
>  	spin_lock_init(&vm->status_lock);
>  	INIT_LIST_HEAD(&vm->invalidated);
>  	INIT_LIST_HEAD(&vm->freed);
> @@ -1232,10 +1232,11 @@ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
>  	struct radeon_bo_va *bo_va, *tmp;
>  	int i, r;
>  
> -	if (!RB_EMPTY_ROOT(&vm->va)) {
> +	if (!RB_EMPTY_ROOT(&vm->va.rb_root)) {
>  		dev_err(rdev->dev, "still active bo inside vm\n");
>  	}
> -	rbtree_postorder_for_each_entry_safe(bo_va, tmp, &vm->va, it.rb) {
> +	rbtree_postorder_for_each_entry_safe(bo_va, tmp,
> +					     &vm->va.rb_root, it.rb) {
>  		interval_tree_remove(&bo_va->it, &vm->va);
>  		r = radeon_bo_reserve(bo_va->bo, false);
>  		if (!r) {
> diff --git a/drivers/infiniband/core/umem_rbtree.c b/drivers/infiniband/core/umem_rbtree.c
> index d176597b4d78..fc801920e341 100644
> --- a/drivers/infiniband/core/umem_rbtree.c
> +++ b/drivers/infiniband/core/umem_rbtree.c
> @@ -72,7 +72,7 @@ INTERVAL_TREE_DEFINE(struct umem_odp_node, rb, u64, __subtree_last,
>  /* @last is not a part of the interval. See comment for function
>   * node_last.
>   */
> -int rbt_ib_umem_for_each_in_range(struct rb_root *root,
> +int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
>  				  u64 start, u64 last,
>  				  umem_call_back cb,
>  				  void *cookie)
> @@ -95,7 +95,7 @@ int rbt_ib_umem_for_each_in_range(struct rb_root *root,
>  }
>  EXPORT_SYMBOL(rbt_ib_umem_for_each_in_range);
>  
> -struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root *root,
> +struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
>  				       u64 addr, u64 length)
>  {
>  	struct umem_odp_node *node;
> diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
> index 3f55d18a3791..5321c6ae2c0c 100644
> --- a/drivers/infiniband/core/uverbs_cmd.c
> +++ b/drivers/infiniband/core/uverbs_cmd.c
> @@ -117,7 +117,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
>  	ucontext->closing = 0;
>  
>  #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
> -	ucontext->umem_tree = RB_ROOT;
> +	ucontext->umem_tree = RB_ROOT_CACHED;
>  	init_rwsem(&ucontext->umem_rwsem);
>  	ucontext->odp_mrs_count = 0;
>  	INIT_LIST_HEAD(&ucontext->no_private_counters);
> diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
> index d41fd87a39f2..5b6626f8feb6 100644
> --- a/drivers/infiniband/hw/hfi1/mmu_rb.c
> +++ b/drivers/infiniband/hw/hfi1/mmu_rb.c
> @@ -54,7 +54,7 @@
>  
>  struct mmu_rb_handler {
>  	struct mmu_notifier mn;
> -	struct rb_root root;
> +	struct rb_root_cached root;
>  	void *ops_arg;
>  	spinlock_t lock;        /* protect the RB tree */
>  	struct mmu_rb_ops *ops;
> @@ -111,7 +111,7 @@ int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm,
>  	if (!handlr)
>  		return -ENOMEM;
>  
> -	handlr->root = RB_ROOT;
> +	handlr->root = RB_ROOT_CACHED;
>  	handlr->ops = ops;
>  	handlr->ops_arg = ops_arg;
>  	INIT_HLIST_NODE(&handlr->mn.hlist);
> @@ -152,9 +152,9 @@ void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler)
>  	INIT_LIST_HEAD(&del_list);
>  
>  	spin_lock_irqsave(&handler->lock, flags);
> -	while ((node = rb_first(&handler->root))) {
> +	while ((node = rb_first_cached(&handler->root))) {
>  		rbnode = rb_entry(node, struct mmu_rb_node, node);
> -		rb_erase(node, &handler->root);
> +		rb_erase_cached(node, &handler->root);
>  		/* move from LRU list to delete list */
>  		list_move(&rbnode->list, &del_list);
>  	}
> @@ -311,7 +311,7 @@ static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
>  {
>  	struct mmu_rb_handler *handler =
>  		container_of(mn, struct mmu_rb_handler, mn);
> -	struct rb_root *root = &handler->root;
> +	struct rb_root_cached *root = &handler->root;
>  	struct mmu_rb_node *node, *ptr = NULL;
>  	unsigned long flags;
>  	bool added = false;
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
> index c49db7c33979..4381c0a9a873 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom.c
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
> @@ -227,7 +227,7 @@ static void __usnic_uiom_reg_release(struct usnic_uiom_pd *pd,
>  	vpn_last = vpn_start + npages - 1;
>  
>  	spin_lock(&pd->lock);
> -	usnic_uiom_remove_interval(&pd->rb_root, vpn_start,
> +	usnic_uiom_remove_interval(&pd->root, vpn_start,
>  					vpn_last, &rm_intervals);
>  	usnic_uiom_unmap_sorted_intervals(&rm_intervals, pd);
>  
> @@ -379,7 +379,7 @@ struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
>  	err = usnic_uiom_get_intervals_diff(vpn_start, vpn_last,
>  						(writable) ? IOMMU_WRITE : 0,
>  						IOMMU_WRITE,
> -						&pd->rb_root,
> +						&pd->root,
>  						&sorted_diff_intervals);
>  	if (err) {
>  		usnic_err("Failed disjoint interval vpn [0x%lx,0x%lx] err %d\n",
> @@ -395,7 +395,7 @@ struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
>  
>  	}
>  
> -	err = usnic_uiom_insert_interval(&pd->rb_root, vpn_start, vpn_last,
> +	err = usnic_uiom_insert_interval(&pd->root, vpn_start, vpn_last,
>  					(writable) ? IOMMU_WRITE : 0);
>  	if (err) {
>  		usnic_err("Failed insert interval vpn [0x%lx,0x%lx] err %d\n",
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.h b/drivers/infiniband/hw/usnic/usnic_uiom.h
> index 45ca7c1613a7..431efe4143f4 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom.h
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom.h
> @@ -55,7 +55,7 @@ struct usnic_uiom_dev {
>  struct usnic_uiom_pd {
>  	struct iommu_domain		*domain;
>  	spinlock_t			lock;
> -	struct rb_root			rb_root;
> +	struct rb_root_cached		root;
>  	struct list_head		devs;
>  	int				dev_cnt;
>  };
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
> index 42b4b4c4e452..d399523206c7 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
> @@ -100,9 +100,9 @@ static int interval_cmp(void *priv, struct list_head *a, struct list_head *b)
>  }
>  
>  static void
> -find_intervals_intersection_sorted(struct rb_root *root, unsigned long start,
> -					unsigned long last,
> -					struct list_head *list)
> +find_intervals_intersection_sorted(struct rb_root_cached *root,
> +				   unsigned long start, unsigned long last,
> +				   struct list_head *list)
>  {
>  	struct usnic_uiom_interval_node *node;
>  
> @@ -118,7 +118,7 @@ find_intervals_intersection_sorted(struct rb_root *root, unsigned long start,
>  
>  int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
>  					int flags, int flag_mask,
> -					struct rb_root *root,
> +					struct rb_root_cached *root,
>  					struct list_head *diff_set)
>  {
>  	struct usnic_uiom_interval_node *interval, *tmp;
> @@ -175,7 +175,7 @@ void usnic_uiom_put_interval_set(struct list_head *intervals)
>  		kfree(interval);
>  }
>  
> -int usnic_uiom_insert_interval(struct rb_root *root, unsigned long start,
> +int usnic_uiom_insert_interval(struct rb_root_cached *root, unsigned long start,
>  				unsigned long last, int flags)
>  {
>  	struct usnic_uiom_interval_node *interval, *tmp;
> @@ -246,8 +246,9 @@ int usnic_uiom_insert_interval(struct rb_root *root, unsigned long start,
>  	return err;
>  }
>  
> -void usnic_uiom_remove_interval(struct rb_root *root, unsigned long start,
> -				unsigned long last, struct list_head *removed)
> +void usnic_uiom_remove_interval(struct rb_root_cached *root,
> +				unsigned long start, unsigned long last,
> +				struct list_head *removed)
>  {
>  	struct usnic_uiom_interval_node *interval;
>  
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
> index c0b0b876ab90..1d7fc3226bca 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
> @@ -48,12 +48,12 @@ struct usnic_uiom_interval_node {
>  
>  extern void
>  usnic_uiom_interval_tree_insert(struct usnic_uiom_interval_node *node,
> -					struct rb_root *root);
> +					struct rb_root_cached *root);
>  extern void
>  usnic_uiom_interval_tree_remove(struct usnic_uiom_interval_node *node,
> -					struct rb_root *root);
> +					struct rb_root_cached *root);
>  extern struct usnic_uiom_interval_node *
> -usnic_uiom_interval_tree_iter_first(struct rb_root *root,
> +usnic_uiom_interval_tree_iter_first(struct rb_root_cached *root,
>  					unsigned long start,
>  					unsigned long last);
>  extern struct usnic_uiom_interval_node *
> @@ -63,7 +63,7 @@ usnic_uiom_interval_tree_iter_next(struct usnic_uiom_interval_node *node,
>   * Inserts {start...last} into {root}.  If there are overlaps,
>   * nodes will be broken up and merged
>   */
> -int usnic_uiom_insert_interval(struct rb_root *root,
> +int usnic_uiom_insert_interval(struct rb_root_cached *root,
>  				unsigned long start, unsigned long last,
>  				int flags);
>  /*
> @@ -71,7 +71,7 @@ int usnic_uiom_insert_interval(struct rb_root *root,
>   * 'removed.' The caller is responsibile for freeing memory of nodes in
>   * 'removed.'
>   */
> -void usnic_uiom_remove_interval(struct rb_root *root,
> +void usnic_uiom_remove_interval(struct rb_root_cached *root,
>  				unsigned long start, unsigned long last,
>  				struct list_head *removed);
>  /*
> @@ -81,7 +81,7 @@ void usnic_uiom_remove_interval(struct rb_root *root,
>  int usnic_uiom_get_intervals_diff(unsigned long start,
>  					unsigned long last, int flags,
>  					int flag_mask,
> -					struct rb_root *root,
> +					struct rb_root_cached *root,
>  					struct list_head *diff_set);
>  /* Call this to free diff_set returned by usnic_uiom_get_intervals_diff */
>  void usnic_uiom_put_interval_set(struct list_head *intervals);
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index e4613a3c362d..88dc214de068 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1272,7 +1272,7 @@ static struct vhost_umem *vhost_umem_alloc(void)
>  	if (!umem)
>  		return NULL;
>  
> -	umem->umem_tree = RB_ROOT;
> +	umem->umem_tree = RB_ROOT_CACHED;
>  	umem->numem = 0;
>  	INIT_LIST_HEAD(&umem->umem_list);
>  
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index f72095868b93..a0278ba6a8b4 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -71,7 +71,7 @@ struct vhost_umem_node {
>  };
>  
>  struct vhost_umem {
> -	struct rb_root umem_tree;
> +	struct rb_root_cached umem_tree;
>  	struct list_head umem_list;
>  	int numem;
>  };
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index 28d2753be094..e61b91e6adf4 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -334,7 +334,7 @@ static void remove_huge_page(struct page *page)
>  }
>  
>  static void
> -hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end)
> +hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end)
>  {
>  	struct vm_area_struct *vma;
>  
> @@ -514,7 +514,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
>  
>  	i_size_write(inode, offset);
>  	i_mmap_lock_write(mapping);
> -	if (!RB_EMPTY_ROOT(&mapping->i_mmap))
> +	if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
>  		hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0);
>  	i_mmap_unlock_write(mapping);
>  	remove_inode_hugepages(inode, offset, LLONG_MAX);
> @@ -539,7 +539,7 @@ static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
>  
>  		inode_lock(inode);
>  		i_mmap_lock_write(mapping);
> -		if (!RB_EMPTY_ROOT(&mapping->i_mmap))
> +		if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
>  			hugetlb_vmdelete_list(&mapping->i_mmap,
>  						hole_start >> PAGE_SHIFT,
>  						hole_end  >> PAGE_SHIFT);
> diff --git a/fs/inode.c b/fs/inode.c
> index 50370599e371..5ddb808ea934 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -353,7 +353,7 @@ void address_space_init_once(struct address_space *mapping)
>  	init_rwsem(&mapping->i_mmap_rwsem);
>  	INIT_LIST_HEAD(&mapping->private_list);
>  	spin_lock_init(&mapping->private_lock);
> -	mapping->i_mmap = RB_ROOT;
> +	mapping->i_mmap = RB_ROOT_CACHED;
>  }
>  EXPORT_SYMBOL(address_space_init_once);
>  
> diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
> index 49b292e98fec..8d10fc97801c 100644
> --- a/include/drm/drm_mm.h
> +++ b/include/drm/drm_mm.h
> @@ -172,7 +172,7 @@ struct drm_mm {
>  	 * according to the (increasing) start address of the memory node. */
>  	struct drm_mm_node head_node;
>  	/* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
> -	struct rb_root interval_tree;
> +	struct rb_root_cached interval_tree;
>  	struct rb_root holes_size;
>  	struct rb_root holes_addr;
>  
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index ed8798255872..d1d521c5025b 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -392,7 +392,7 @@ struct address_space {
>  	struct radix_tree_root	page_tree;	/* radix tree of all pages */
>  	spinlock_t		tree_lock;	/* and lock protecting it */
>  	atomic_t		i_mmap_writable;/* count VM_SHARED mappings */
> -	struct rb_root		i_mmap;		/* tree of private and shared mappings */
> +	struct rb_root_cached	i_mmap;		/* tree of private and shared mappings */
>  	struct rw_semaphore	i_mmap_rwsem;	/* protect tree, count, list */
>  	/* Protected by tree_lock together with the radix tree */
>  	unsigned long		nrpages;	/* number of total pages */
> @@ -486,7 +486,7 @@ static inline void i_mmap_unlock_read(struct address_space *mapping)
>   */
>  static inline int mapping_mapped(struct address_space *mapping)
>  {
> -	return	!RB_EMPTY_ROOT(&mapping->i_mmap);
> +	return	!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root);
>  }
>  
>  /*
> diff --git a/include/linux/interval_tree.h b/include/linux/interval_tree.h
> index 724556aa3c95..202ee1283f4b 100644
> --- a/include/linux/interval_tree.h
> +++ b/include/linux/interval_tree.h
> @@ -11,13 +11,15 @@ struct interval_tree_node {
>  };
>  
>  extern void
> -interval_tree_insert(struct interval_tree_node *node, struct rb_root *root);
> +interval_tree_insert(struct interval_tree_node *node,
> +		     struct rb_root_cached *root);
>  
>  extern void
> -interval_tree_remove(struct interval_tree_node *node, struct rb_root *root);
> +interval_tree_remove(struct interval_tree_node *node,
> +		     struct rb_root_cached *root);
>  
>  extern struct interval_tree_node *
> -interval_tree_iter_first(struct rb_root *root,
> +interval_tree_iter_first(struct rb_root_cached *root,
>  			 unsigned long start, unsigned long last);
>  
>  extern struct interval_tree_node *
> diff --git a/include/linux/interval_tree_generic.h b/include/linux/interval_tree_generic.h
> index 58370e1862ad..f096423c8cbd 100644
> --- a/include/linux/interval_tree_generic.h
> +++ b/include/linux/interval_tree_generic.h
> @@ -65,11 +65,13 @@ RB_DECLARE_CALLBACKS(static, ITPREFIX ## _augment, ITSTRUCT, ITRB,	      \
>  									      \
>  /* Insert / remove interval nodes from the tree */			      \
>  									      \
> -ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, struct rb_root *root)	      \
> +ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node,			      \
> +				  struct rb_root_cached *root)	 	      \
>  {									      \
> -	struct rb_node **link = &root->rb_node, *rb_parent = NULL;	      \
> +	struct rb_node **link = &root->rb_root.rb_node, *rb_parent = NULL;    \
>  	ITTYPE start = ITSTART(node), last = ITLAST(node);		      \
>  	ITSTRUCT *parent;						      \
> +	bool leftmost = true;						      \
>  									      \
>  	while (*link) {							      \
>  		rb_parent = *link;					      \
> @@ -78,18 +80,22 @@ ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, struct rb_root *root)	      \
>  			parent->ITSUBTREE = last;			      \
>  		if (start < ITSTART(parent))				      \
>  			link = &parent->ITRB.rb_left;			      \
> -		else							      \
> +		else {							      \
>  			link = &parent->ITRB.rb_right;			      \
> +			leftmost = false;				      \
> +		}							      \
>  	}								      \
>  									      \
>  	node->ITSUBTREE = last;						      \
>  	rb_link_node(&node->ITRB, rb_parent, link);			      \
> -	rb_insert_augmented(&node->ITRB, root, &ITPREFIX ## _augment);	      \
> +	rb_insert_augmented_cached(&node->ITRB, root,			      \
> +				   leftmost, &ITPREFIX ## _augment);	      \
>  }									      \
>  									      \
> -ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, struct rb_root *root)	      \
> +ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node,			      \
> +				  struct rb_root_cached *root)		      \
>  {									      \
> -	rb_erase_augmented(&node->ITRB, root, &ITPREFIX ## _augment);	      \
> +	rb_erase_augmented_cached(&node->ITRB, root, &ITPREFIX ## _augment);  \
>  }									      \
>  									      \
>  /*									      \
> @@ -140,15 +146,35 @@ ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last)	      \
>  }									      \
>  									      \
>  ITSTATIC ITSTRUCT *							      \
> -ITPREFIX ## _iter_first(struct rb_root *root, ITTYPE start, ITTYPE last)      \
> +ITPREFIX ## _iter_first(struct rb_root_cached *root,			      \
> +			ITTYPE start, ITTYPE last)			      \
>  {									      \
> -	ITSTRUCT *node;							      \
> +	ITSTRUCT *node, *leftmost;					      \
>  									      \
> -	if (!root->rb_node)						      \
> +	if (!root->rb_root.rb_node)					      \
>  		return NULL;						      \
> -	node = rb_entry(root->rb_node, ITSTRUCT, ITRB);			      \
> +									      \
> +	/*								      \
> +	 * Fastpath range intersection/overlap between A: [a0, a1] and	      \
> +	 * B: [b0, b1] is given by:					      \
> +	 *								      \
> +	 *         a0 <= b1 && b0 <= a1					      \
> +	 *								      \
> +	 *  ... where A holds the lock range and B holds the smallest	      \
> +	 * 'start' and largest 'last' in the tree. For the later, we	      \
> +	 * rely on the root node, which by augmented interval tree	      \
> +	 * property, holds the largest value in its last-in-subtree.	      \
> +	 * This allows mitigating some of the tree walk overhead for	      \
> +	 * for non-intersecting ranges, maintained and consulted in O(1).     \
> +	 */								      \
> +	node = rb_entry(root->rb_root.rb_node, ITSTRUCT, ITRB);		      \
>  	if (node->ITSUBTREE < start)					      \
>  		return NULL;						      \
> +									      \
> +	leftmost = rb_entry(root->rb_leftmost, ITSTRUCT, ITRB);		      \
> +	if (ITSTART(leftmost) > last)					      \
> +		return NULL;						      \
> +									      \
>  	return ITPREFIX ## _subtree_search(node, start, last);		      \
>  }									      \
>  									      \
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 46b9ac5e8569..3a2652efbbfb 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1992,13 +1992,13 @@ extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
>  
>  /* interval_tree.c */
>  void vma_interval_tree_insert(struct vm_area_struct *node,
> -			      struct rb_root *root);
> +			      struct rb_root_cached *root);
>  void vma_interval_tree_insert_after(struct vm_area_struct *node,
>  				    struct vm_area_struct *prev,
> -				    struct rb_root *root);
> +				    struct rb_root_cached *root);
>  void vma_interval_tree_remove(struct vm_area_struct *node,
> -			      struct rb_root *root);
> -struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
> +			      struct rb_root_cached *root);
> +struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root_cached *root,
>  				unsigned long start, unsigned long last);
>  struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
>  				unsigned long start, unsigned long last);
> @@ -2008,11 +2008,12 @@ struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
>  	     vma; vma = vma_interval_tree_iter_next(vma, start, last))
>  
>  void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
> -				   struct rb_root *root);
> +				   struct rb_root_cached *root);
>  void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
> -				   struct rb_root *root);
> -struct anon_vma_chain *anon_vma_interval_tree_iter_first(
> -	struct rb_root *root, unsigned long start, unsigned long last);
> +				   struct rb_root_cached *root);
> +struct anon_vma_chain *
> +anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
> +				  unsigned long start, unsigned long last);
>  struct anon_vma_chain *anon_vma_interval_tree_iter_next(
>  	struct anon_vma_chain *node, unsigned long start, unsigned long last);
>  #ifdef CONFIG_DEBUG_VM_RB
> diff --git a/include/linux/rmap.h b/include/linux/rmap.h
> index 43ef2c30cb0f..22c298c6cc26 100644
> --- a/include/linux/rmap.h
> +++ b/include/linux/rmap.h
> @@ -55,7 +55,9 @@ struct anon_vma {
>  	 * is serialized by a system wide lock only visible to
>  	 * mm_take_all_locks() (mm_all_locks_mutex).
>  	 */
> -	struct rb_root rb_root;	/* Interval tree of private "related" vmas */
> +
> +	/* Interval tree of private "related" vmas */
> +	struct rb_root_cached rb_root;
>  };
>  
>  /*
> diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h
> index fb67554aabd6..5eb7f5bc8248 100644
> --- a/include/rdma/ib_umem_odp.h
> +++ b/include/rdma/ib_umem_odp.h
> @@ -111,22 +111,25 @@ int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 start_offset, u64 bcnt,
>  void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 start_offset,
>  				 u64 bound);
>  
> -void rbt_ib_umem_insert(struct umem_odp_node *node, struct rb_root *root);
> -void rbt_ib_umem_remove(struct umem_odp_node *node, struct rb_root *root);
> +void rbt_ib_umem_insert(struct umem_odp_node *node,
> +			struct rb_root_cached *root);
> +void rbt_ib_umem_remove(struct umem_odp_node *node,
> +			struct rb_root_cached *root);
>  typedef int (*umem_call_back)(struct ib_umem *item, u64 start, u64 end,
>  			      void *cookie);
>  /*
>   * Call the callback on each ib_umem in the range. Returns the logical or of
>   * the return values of the functions called.
>   */
> -int rbt_ib_umem_for_each_in_range(struct rb_root *root, u64 start, u64 end,
> +int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
> +				  u64 start, u64 end,
>  				  umem_call_back cb, void *cookie);
>  
>  /*
>   * Find first region intersecting with address range.
>   * Return NULL if not found
>   */
> -struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root *root,
> +struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
>  				       u64 addr, u64 length);
>  
>  static inline int ib_umem_mmu_notifier_retry(struct ib_umem *item,
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 593ad2640d2f..81665480a4ab 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -1420,7 +1420,7 @@ struct ib_ucontext {
>  
>  	struct pid             *tgid;
>  #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
> -	struct rb_root      umem_tree;
> +	struct rb_root_cached   umem_tree;
>  	/*
>  	 * Protects .umem_rbroot and tree, as well as odp_mrs_count and
>  	 * mmu notifiers registration.
> diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
> index df495fe81421..0e343fd29570 100644
> --- a/lib/interval_tree_test.c
> +++ b/lib/interval_tree_test.c
> @@ -19,14 +19,14 @@ __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
>  
>  __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
>  
> -static struct rb_root root = RB_ROOT;
> +static struct rb_root_cached root = RB_ROOT_CACHED;
>  static struct interval_tree_node *nodes = NULL;
>  static u32 *queries = NULL;
>  
>  static struct rnd_state rnd;
>  
>  static inline unsigned long
> -search(struct rb_root *root, unsigned long start, unsigned long last)
> +search(struct rb_root_cached *root, unsigned long start, unsigned long last)
>  {
>  	struct interval_tree_node *node;
>  	unsigned long results = 0;
> diff --git a/mm/interval_tree.c b/mm/interval_tree.c
> index f2c2492681bf..b47664358796 100644
> --- a/mm/interval_tree.c
> +++ b/mm/interval_tree.c
> @@ -28,7 +28,7 @@ INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb,
>  /* Insert node immediately after prev in the interval tree */
>  void vma_interval_tree_insert_after(struct vm_area_struct *node,
>  				    struct vm_area_struct *prev,
> -				    struct rb_root *root)
> +				    struct rb_root_cached *root)
>  {
>  	struct rb_node **link;
>  	struct vm_area_struct *parent;
> @@ -55,7 +55,7 @@ void vma_interval_tree_insert_after(struct vm_area_struct *node,
>  
>  	node->shared.rb_subtree_last = last;
>  	rb_link_node(&node->shared.rb, &parent->shared.rb, link);
> -	rb_insert_augmented(&node->shared.rb, root,
> +	rb_insert_augmented(&node->shared.rb, &root->rb_root,
>  			    &vma_interval_tree_augment);
>  }
>  
> @@ -74,7 +74,7 @@ INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last,
>  		     static inline, __anon_vma_interval_tree)
>  
>  void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
> -				   struct rb_root *root)
> +				   struct rb_root_cached *root)
>  {
>  #ifdef CONFIG_DEBUG_VM_RB
>  	node->cached_vma_start = avc_start_pgoff(node);
> @@ -84,13 +84,13 @@ void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
>  }
>  
>  void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
> -				   struct rb_root *root)
> +				   struct rb_root_cached *root)
>  {
>  	__anon_vma_interval_tree_remove(node, root);
>  }
>  
>  struct anon_vma_chain *
> -anon_vma_interval_tree_iter_first(struct rb_root *root,
> +anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
>  				  unsigned long first, unsigned long last)
>  {
>  	return __anon_vma_interval_tree_iter_first(root, first, last);
> diff --git a/mm/memory.c b/mm/memory.c
> index 0e517be91a89..33cb79f73394 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2593,7 +2593,7 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma,
>  	zap_page_range_single(vma, start_addr, end_addr - start_addr, details);
>  }
>  
> -static inline void unmap_mapping_range_tree(struct rb_root *root,
> +static inline void unmap_mapping_range_tree(struct rb_root_cached *root,
>  					    struct zap_details *details)
>  {
>  	struct vm_area_struct *vma;
> @@ -2657,7 +2657,7 @@ void unmap_mapping_range(struct address_space *mapping,
>  		details.last_index = ULONG_MAX;
>  
>  	i_mmap_lock_write(mapping);
> -	if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap)))
> +	if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root)))
>  		unmap_mapping_range_tree(&mapping->i_mmap, &details);
>  	i_mmap_unlock_write(mapping);
>  }
> diff --git a/mm/mmap.c b/mm/mmap.c
> index f19efcf75418..8121c70df96f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -684,7 +684,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
>  	struct mm_struct *mm = vma->vm_mm;
>  	struct vm_area_struct *next = vma->vm_next, *orig_vma = vma;
>  	struct address_space *mapping = NULL;
> -	struct rb_root *root = NULL;
> +	struct rb_root_cached *root = NULL;
>  	struct anon_vma *anon_vma = NULL;
>  	struct file *file = vma->vm_file;
>  	bool start_changed = false, end_changed = false;
> @@ -3314,7 +3314,7 @@ static DEFINE_MUTEX(mm_all_locks_mutex);
>  
>  static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
>  {
> -	if (!test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) {
> +	if (!test_bit(0, (unsigned long *) &anon_vma->rb_root.rb_root.rb_node)) {
>  		/*
>  		 * The LSB of head.next can't change from under us
>  		 * because we hold the mm_all_locks_mutex.
> @@ -3330,7 +3330,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
>  		 * anon_vma->root->rwsem.
>  		 */
>  		if (__test_and_set_bit(0, (unsigned long *)
> -				       &anon_vma->root->rb_root.rb_node))
> +				       &anon_vma->root->rb_root.rb_root.rb_node))
>  			BUG();
>  	}
>  }
> @@ -3432,7 +3432,7 @@ int mm_take_all_locks(struct mm_struct *mm)
>  
>  static void vm_unlock_anon_vma(struct anon_vma *anon_vma)
>  {
> -	if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) {
> +	if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) {
>  		/*
>  		 * The LSB of head.next can't change to 0 from under
>  		 * us because we hold the mm_all_locks_mutex.
> @@ -3446,7 +3446,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma)
>  		 * anon_vma->root->rwsem.
>  		 */
>  		if (!__test_and_clear_bit(0, (unsigned long *)
> -					  &anon_vma->root->rb_root.rb_node))
> +					  &anon_vma->root->rb_root.rb_root.rb_node))
>  			BUG();
>  		anon_vma_unlock_write(anon_vma);
>  	}
> diff --git a/mm/rmap.c b/mm/rmap.c
> index ced14f1af6dc..ad479e5e081d 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -390,7 +390,7 @@ void unlink_anon_vmas(struct vm_area_struct *vma)
>  		 * Leave empty anon_vmas on the list - we'll need
>  		 * to free them outside the lock.
>  		 */
> -		if (RB_EMPTY_ROOT(&anon_vma->rb_root)) {
> +		if (RB_EMPTY_ROOT(&anon_vma->rb_root.rb_root)) {
>  			anon_vma->parent->degree--;
>  			continue;
>  		}
> @@ -424,7 +424,7 @@ static void anon_vma_ctor(void *data)
>  
>  	init_rwsem(&anon_vma->rwsem);
>  	atomic_set(&anon_vma->refcount, 0);
> -	anon_vma->rb_root = RB_ROOT;
> +	anon_vma->rb_root = RB_ROOT_CACHED;
>  }
>  
>  void __init anon_vma_init(void)
> -- 
> 2.12.0


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