diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 978194dc2bb8..c0f5d87b154d 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1908,9 +1908,22 @@ static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
 #define VMAP_BLOCK		0x2 /* mark out the vmap_block sub-type*/
 #define VMAP_FLAGS_MASK		0x3
 
+/*
+ * We should probably have a fallback mechanism to allocate virtual memory
+ * out of partially filled vmap blocks. However vmap block sizing should be
+ * fairly reasonable according to the vmalloc size, so it shouldn't be a
+ * big problem.
+ */
 struct vmap_block_queue {
 	spinlock_t lock;
 	struct list_head free;
+
+	/*
+	 * An xarray requires an extra memory dynamically to
+	 * be allocated. If it is an issue, we can use rb-tree
+	 * instead.
+	 */
+	struct xarray vmap_blocks;
 };
 
 struct vmap_block {
@@ -1927,25 +1940,47 @@ struct vmap_block {
 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
 
-/*
- * XArray of vmap blocks, indexed by address, to quickly find a vmap block
- * in the free path. Could get rid of this if we change the API to return a
- * "cookie" from alloc, to be passed to free. But no big deal yet.
+/**
+ * In order to fast access to any "vmap_block" associated with a
+ * specific address, we store them into a per-cpu xarray. A hash
+ * function is addr_to_vbq() whereas a key is a vb->va->va_start
+ * value.
+ *
+ * Please note, a vmap_block_queue, which is a per-cpu, is not
+ * serialized by a raw_smp_processor_id() current CPU, instead
+ * it is chosen based on a CPU-index it belongs to, i.e. it is
+ * a hash-table.
+ *
+ * An example:
+ *
+ *  CPU_1  CPU_2  CPU_0
+ *    |      |      |
+ *    V      V      V
+ * 0     10     20     30     40     50     60
+ * |------|------|------|------|------|------|...<vmap address space>
+ *   CPU0   CPU1   CPU2   CPU0   CPU1   CPU2
+ *
+ * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus
+ *   it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock;
+ *
+ * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus
+ *   it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock;
+ *
+ * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus
+ *   it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock.
  */
-static DEFINE_XARRAY(vmap_blocks);
+static struct vmap_block_queue *
+addr_to_vbq(unsigned long addr)
+{
+	int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus();
 
-/*
- * We should probably have a fallback mechanism to allocate virtual memory
- * out of partially filled vmap blocks. However vmap block sizing should be
- * fairly reasonable according to the vmalloc size, so it shouldn't be a
- * big problem.
- */
+	return &per_cpu(vmap_block_queue, index);
+}
 
-static unsigned long addr_to_vb_idx(unsigned long addr)
+static unsigned long
+addr_to_vb_va_start(unsigned long addr)
 {
-	addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
-	addr /= VMAP_BLOCK_SIZE;
-	return addr;
+	return rounddown(addr, VMAP_BLOCK_SIZE);
 }
 
 static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
@@ -1953,7 +1988,7 @@ static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
 	unsigned long addr;
 
 	addr = va_start + (pages_off << PAGE_SHIFT);
-	BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
+	WARN_ON_ONCE(addr_to_vb_va_start(addr) != va_start);
 	return (void *)addr;
 }
 
@@ -1970,7 +2005,6 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 	struct vmap_block_queue *vbq;
 	struct vmap_block *vb;
 	struct vmap_area *va;
-	unsigned long vb_idx;
 	int node, err;
 	void *vaddr;
 
@@ -2003,8 +2037,8 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 	bitmap_set(vb->used_map, 0, (1UL << order));
 	INIT_LIST_HEAD(&vb->free_list);
 
-	vb_idx = addr_to_vb_idx(va->va_start);
-	err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask);
+	vbq = addr_to_vbq(va->va_start);
+	err = xa_insert(&vbq->vmap_blocks, va->va_start, vb, gfp_mask);
 	if (err) {
 		kfree(vb);
 		free_vmap_area(va);
@@ -2021,9 +2055,11 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 
 static void free_vmap_block(struct vmap_block *vb)
 {
+	struct vmap_block_queue *vbq;
 	struct vmap_block *tmp;
 
-	tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));
+	vbq = addr_to_vbq(vb->va->va_start);
+	tmp = xa_erase(&vbq->vmap_blocks, vb->va->va_start);
 	BUG_ON(tmp != vb);
 
 	spin_lock(&vmap_area_lock);
@@ -2135,6 +2171,7 @@ static void vb_free(unsigned long addr, unsigned long size)
 	unsigned long offset;
 	unsigned int order;
 	struct vmap_block *vb;
+	struct vmap_block_queue *vbq;
 
 	BUG_ON(offset_in_page(size));
 	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -2143,7 +2180,10 @@ static void vb_free(unsigned long addr, unsigned long size)
 
 	order = get_order(size);
 	offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
-	vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));
+
+	vbq = addr_to_vbq(addr);
+	vb = xa_load(&vbq->vmap_blocks, addr_to_vb_va_start(addr));
+
 	spin_lock(&vb->lock);
 	bitmap_clear(vb->used_map, offset, (1UL << order));
 	spin_unlock(&vb->lock);
@@ -3486,6 +3526,7 @@ static void vmap_ram_vread(char *buf, char *addr, int count, unsigned long flags
 {
 	char *start;
 	struct vmap_block *vb;
+	struct vmap_block_queue *vbq;
 	unsigned long offset;
 	unsigned int rs, re, n;
 
@@ -3503,7 +3544,8 @@ static void vmap_ram_vread(char *buf, char *addr, int count, unsigned long flags
 	 * Area is split into regions and tracked with vmap_block, read out
 	 * each region and zero fill the hole between regions.
 	 */
-	vb = xa_load(&vmap_blocks, addr_to_vb_idx((unsigned long)addr));
+	vbq = addr_to_vbq((unsigned long) addr);
+	vb = xa_load(&vbq->vmap_blocks, addr_to_vb_va_start((unsigned long) addr));
 	if (!vb)
 		goto finished;
 
@@ -4272,6 +4314,7 @@ void __init vmalloc_init(void)
 		p = &per_cpu(vfree_deferred, i);
 		init_llist_head(&p->list);
 		INIT_WORK(&p->wq, delayed_vfree_work);
+		xa_init(&vbq->vmap_blocks);
 	}
 
 	/* Import existing vmlist entries. */
