diff --git a/arch/x86/kernel/memory.c b/arch/x86/kernel/memory.c
index 7ddaa64d..bae4b1ce 100644
--- a/arch/x86/kernel/memory.c
+++ b/arch/x86/kernel/memory.c
@@ -1303,132 +1303,6 @@ int ihk_mc_pt_change_attr_range(page_table_t pt, void *start0, void *end0,
 	return walk_pte_l4(pt, 0, start, end, &change_attr_range_l4, &args);
 }
 
-static int alloc_range_l1(void *arg0, pte_t *ptep, uint64_t base,
-		uint64_t start, uint64_t end)
-{
-	enum ihk_mc_pt_attribute *attrp = arg0;
-	void *vp;
-
-	if (*ptep == PTE_NULL) {
-		/* not mapped */
-		vp = ihk_mc_alloc_pages(1, IHK_MC_AP_NOWAIT);
-		if (vp == NULL) {
-			return -ENOMEM;
-		}
-		memset(vp, 0, PTL1_SIZE);
-
-		*ptep = virt_to_phys(vp) | attr_to_l1attr(*attrp);
-	}
-	else if (!(*ptep & PFL1_PRESENT)) {
-		kprintf("alloc_range_l1(%p,%p,%lx,%lx,%lx):inactive %lx\n",
-				arg0, ptep, base, start, end, *ptep);
-		return -EBUSY;
-	}
-
-	return 0;
-}
-
-static int alloc_range_l2(void *arg0, pte_t *ptep, uint64_t base,
-		uint64_t start, uint64_t end)
-{
-	struct page_table *pt;
-#ifdef USE_LARGE_PAGES
-	enum ihk_mc_pt_attribute *attrp = arg0;
-	void *vp;
-#endif /* USE_LARGE_PAGES */
-
-	if (*ptep != PTE_NULL) {
-		if (!(*ptep & PFL2_PRESENT)) {
-			kprintf("alloc_range_l2(%p,%p,%lx,%lx,%lx):inactive %lx\n",
-					arg0, ptep, base, start, end, *ptep);
-			return -EBUSY;
-		}
-		else if (*ptep & PFL2_SIZE) {
-			return 0;
-		}
-
-		pt = phys_to_virt(*ptep & PT_PHYSMASK);
-	}
-	else {
-#ifdef USE_LARGE_PAGES
-		if ((start <= base) && ((base + PTL2_SIZE) <= end)) {
-			vp = ihk_mc_alloc_aligned_pages(LARGE_PAGE_SIZE/PAGE_SIZE,
-					LARGE_PAGE_P2ALIGN, IHK_MC_AP_NOWAIT);
-			if (vp != NULL) {
-				memset(vp, 0, PTL2_SIZE);
-
-				*ptep = virt_to_phys(vp)
-					| attr_to_l2attr(*attrp | PTATTR_LARGEPAGE);
-				return 0;
-			}
-		}
-#endif /* USE_LARGE_PAGES */
-		pt = __alloc_new_pt(IHK_MC_AP_NOWAIT);
-		if (pt == NULL) {
-			return -ENOMEM;
-		}
-
-		*ptep = virt_to_phys(pt) | PFL2_PDIR_ATTR;
-	}
-
-	return walk_pte_l1(pt, base, start, end, &alloc_range_l1, arg0);
-}
-
-static int alloc_range_l3(void *arg0, pte_t *ptep, uint64_t base,
-		uint64_t start, uint64_t end)
-{
-	struct page_table *pt;
-
-	if (*ptep != PTE_NULL) {
-		if (!(*ptep & PFL3_PRESENT)) {
-			kprintf("alloc_range_l3(%p,%p,%lx,%lx,%lx):inactive %lx\n",
-					arg0, ptep, base, start, end, *ptep);
-			panic("alloc_range_l3:inactive");
-		}
-		pt = phys_to_virt(*ptep & PT_PHYSMASK);
-	}
-	else {
-		pt = __alloc_new_pt(IHK_MC_AP_NOWAIT);
-		if (pt == NULL) {
-			return -ENOMEM;
-		}
-		*ptep = virt_to_phys(pt) | PFL3_PDIR_ATTR;
-	}
-
-	return walk_pte_l2(pt, base, start, end, &alloc_range_l2, arg0);
-}
-
-static int alloc_range_l4(void *arg0, pte_t *ptep, uint64_t base,
-		uint64_t start, uint64_t end)
-{
-	struct page_table *pt;
-
-	if (*ptep != PTE_NULL) {
-		if (!(*ptep & PFL4_PRESENT)) {
-			kprintf("alloc_range_l4(%p,%p,%lx,%lx,%lx):inactive %lx\n",
-					arg0, ptep, base, start, end, *ptep);
-			panic("alloc_range_l4:inactive");
-		}
-		pt = phys_to_virt(*ptep & PT_PHYSMASK);
-	}
-	else {
-		pt = __alloc_new_pt(IHK_MC_AP_NOWAIT);
-		if (pt == NULL) {
-			return -ENOMEM;
-		}
-		*ptep = virt_to_phys(pt) | PFL4_PDIR_ATTR;
-	}
-
-	return walk_pte_l3(pt, base, start, end, &alloc_range_l3, arg0);
-}
-
-int ihk_mc_pt_alloc_range(page_table_t pt, void *start, void *end,
-		enum ihk_mc_pt_attribute attr)
-{
-	return walk_pte_l4(pt, 0, (intptr_t)start, (intptr_t)end,
-			&alloc_range_l4, &attr);
-}
-
 static pte_t *lookup_pte(struct page_table *pt, uintptr_t virt,
 		uintptr_t *basep, size_t *sizep, int *p2alignp)
 {
diff --git a/kernel/process.c b/kernel/process.c
index 0cb19aaf..91f16740 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -1214,21 +1214,6 @@ int change_prot_process_memory_range(struct process_vm *vm,
 		goto out;
 	}
 
-	if (((range->flag & VR_PROT_MASK) == PROT_NONE)
-			&& !(range->flag & VR_DEMAND_PAGING)) {
-		ihk_mc_spinlock_lock_noirq(&vm->page_table_lock);
-		error = ihk_mc_pt_alloc_range(vm->address_space->page_table,
-				(void *)range->start, (void *)range->end,
-				newattr);
-		ihk_mc_spinlock_unlock_noirq(&vm->page_table_lock);
-		if (error) {
-			ekprintf("change_prot_process_memory_range(%p,%lx-%lx,%lx):"
-					"ihk_mc_pt_alloc_range failed: %d\n",
-					vm, range->start, range->end, protflag, error);
-			goto out;
-		}
-	}
-
 	range->flag = newflag;
 	error = 0;
 out:
diff --git a/lib/include/ihk/mm.h b/lib/include/ihk/mm.h
index d17b4375..3bc59183 100644
--- a/lib/include/ihk/mm.h
+++ b/lib/include/ihk/mm.h
@@ -127,8 +127,6 @@ int ihk_mc_pt_free_range(page_table_t pt, struct process_vm *vm,
 int ihk_mc_pt_change_attr_range(page_table_t pt, void *start, void *end,
 		enum ihk_mc_pt_attribute clrattr,
 		enum ihk_mc_pt_attribute setattr);
-int ihk_mc_pt_alloc_range(page_table_t pt, void *start, void *end,
-		enum ihk_mc_pt_attribute attr);
 pte_t *ihk_mc_pt_lookup_pte(page_table_t pt, void *virt, void **pgbasep, size_t *pgsizep, int *p2alignp);
 int ihk_mc_pt_set_range(page_table_t pt, struct process_vm *vm, void *start, 
 		void *end, uintptr_t phys, enum ihk_mc_pt_attribute attr);