diff --git a/arch/x86/kernel/memory.c b/arch/x86/kernel/memory.c
index 43285b79..01108e06 100644
--- a/arch/x86/kernel/memory.c
+++ b/arch/x86/kernel/memory.c
@@ -2261,6 +2261,7 @@ int read_process_vm(struct process_vm *vm, void *kdst, const void *usrc, size_t
 	if ((ustart < vm->region.user_start)
 			|| (vm->region.user_end <= ustart)
 			|| ((vm->region.user_end - ustart) < siz)) {
+		kprintf("%s: error: out of user range\n", __FUNCTION__);
 		return -EFAULT;
 	}
 
@@ -2268,6 +2269,7 @@ int read_process_vm(struct process_vm *vm, void *kdst, const void *usrc, size_t
 	for (addr = ustart & PAGE_MASK; addr < uend; addr += PAGE_SIZE) {
 		error = page_fault_process_vm(vm, (void *)addr, reason);
 		if (error) {
+			kprintf("%s: error: PF for %p failed\n", __FUNCTION__, addr);
 			return error;
 		}
 	}
@@ -2283,6 +2285,7 @@ int read_process_vm(struct process_vm *vm, void *kdst, const void *usrc, size_t
 
 		error = ihk_mc_pt_virt_to_phys(vm->address_space->page_table, from, &pa);
 		if (error) {
+			kprintf("%s: error: resolving physical address or %p\n", __FUNCTION__, from);
 			return error;
 		}
 
diff --git a/executer/kernel/mcctrl/syscall.c b/executer/kernel/mcctrl/syscall.c
index db4d75e8..e14ffb2b 100644
--- a/executer/kernel/mcctrl/syscall.c
+++ b/executer/kernel/mcctrl/syscall.c
@@ -899,7 +899,7 @@ static int pager_req_create(ihk_os_t os, int fd, uintptr_t result_pa)
 
 	error = vfs_fstat(fd, &st);
 	if (error) {
-		dprintk("pager_req_create(%d,%lx):vfs_stat failed. %d\n", fd, (long)result_pa, error);
+		printk("pager_req_create(%d,%lx):vfs_stat failed. %d\n", fd, (long)result_pa, error);
 		goto out;
 	}
 	if (S_ISCHR(st.mode) && (MAJOR(st.rdev) == 1)) {
@@ -914,7 +914,7 @@ static int pager_req_create(ihk_os_t os, int fd, uintptr_t result_pa)
 	file = fget(fd);
 	if (!file) {
 		error = -EBADF;
-		dprintk("pager_req_create(%d,%lx):file not found. %d\n", fd, (long)result_pa, error);
+		printk("pager_req_create(%d,%lx):file not found. %d\n", fd, (long)result_pa, error);
 		goto out;
 	}
 
@@ -937,7 +937,7 @@ static int pager_req_create(ihk_os_t os, int fd, uintptr_t result_pa)
 	}
 	if (!(maxprot & PROT_READ)) {
 		error = -EACCES;
-		dprintk("pager_req_create(%d,%lx):cannot read file. %d\n", fd, (long)result_pa, error);
+		printk("pager_req_create(%d,%lx):cannot read file. %d\n", fd, (long)result_pa, error);
 		goto out;
 	}
 
@@ -1209,7 +1209,7 @@ struct pager_map_result {
 };
 
 static int pager_req_map(ihk_os_t os, int fd, size_t len, off_t off,
-		uintptr_t result_rpa, int prot)
+		uintptr_t result_rpa, int prot_and_flags)
 {
 	const ihk_device_t dev = ihk_os_to_dev(os);
 	const off_t pgoff = off / PAGE_SIZE;
@@ -1237,27 +1237,33 @@ static int pager_req_map(ihk_os_t os, int fd, size_t len, off_t off,
 	}
 
 	maxprot = 0;
-	if (file->f_mode & FMODE_READ) {
+	if ((file->f_mode & FMODE_READ) && 
+			(prot_and_flags ? (prot_and_flags & PROT_READ) : 1)) {
 		maxprot |= PROT_READ;
 	}
-	if ((file->f_mode & FMODE_WRITE) && (prot ? (prot & PROT_WRITE) : 1)) {
+	if ((file->f_mode & FMODE_WRITE) && 
+			(prot_and_flags ? (prot_and_flags & PROT_WRITE) : 1)) {
 		maxprot |= PROT_WRITE;
 	}
-	if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) {
+	if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC) &&
+			(prot_and_flags ? (prot_and_flags & PROT_EXEC) : 1)) {
 		maxprot |= PROT_EXEC;
 	}
 
 	down_write(&current->mm->mmap_sem);
 #define	ANY_WHERE 0
+	if (prot_and_flags & MAP_LOCKED) prot_and_flags |= MAP_POPULATE;
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,5,0)
-	va = do_mmap_pgoff(file, ANY_WHERE, len, maxprot, MAP_SHARED, pgoff);
+	va = do_mmap_pgoff(file, ANY_WHERE, len, maxprot, 
+			MAP_SHARED | (prot_and_flags & (MAP_POPULATE | MAP_LOCKED)), pgoff);
 #endif	
 
 	up_write(&current->mm->mmap_sem);
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
-	va = vm_mmap(file, ANY_WHERE, len, maxprot, MAP_SHARED, pgoff << PAGE_SHIFT);
+	va = vm_mmap(file, ANY_WHERE, len, maxprot, MAP_SHARED | 
+			(prot_and_flags & (MAP_POPULATE | MAP_LOCKED)), pgoff << PAGE_SHIFT);
 #endif
 
 	if (IS_ERR_VALUE(va)) {
@@ -1271,8 +1277,8 @@ static int pager_req_map(ihk_os_t os, int fd, size_t len, off_t off,
 	pager->map_len = len;
 	pager->map_off = off;
 	
-	dprintk("pager_req_map(%s): 0x%lx - 0x%lx (len: %lu)\n", 
-			file->f_dentry->d_name.name, va, va + len, len);
+	dprintk("pager_req_map(%s): 0x%lx - 0x%lx (len: %lu), map_off: %lu\n", 
+			file->f_dentry->d_name.name, va, va + len, len, off);
 
 	phys = ihk_device_map_memory(dev, result_rpa, sizeof(*resp));
 	resp = ihk_device_map_virtual(dev, phys, sizeof(*resp), NULL, 0);
@@ -1309,6 +1315,7 @@ static int pager_req_pfn(ihk_os_t os, uintptr_t handle, off_t off, uintptr_t ppf
 	pte_t *pte;
 	uintptr_t phys;
 	uintptr_t *ppfn;
+	int page_fault_attempted = 0;
 
 	dprintk("pager_req_pfn(%p,%lx,%lx)\n", os, handle, off);
 
@@ -1324,6 +1331,7 @@ static int pager_req_pfn(ihk_os_t os, uintptr_t handle, off_t off, uintptr_t ppf
 	pfn = PFN_VALID;	/* デフォルトは not present */
 
 	down_read(&current->mm->mmap_sem);
+retry:	
 	pgd = pgd_offset(current->mm, va);
 	if (!pgd_none(*pgd) && !pgd_bad(*pgd) && pgd_present(*pgd)) {
 		pud = pud_offset(pgd, va);
@@ -1346,6 +1354,33 @@ static int pager_req_pfn(ihk_os_t os, uintptr_t handle, off_t off, uintptr_t ppf
 			}
 		}
 	}
+
+	/* If not present, try to fault it */
+	if (!(pfn & PFN_PRESENT) && !page_fault_attempted) {
+		unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+		struct vm_area_struct *vma;
+		int fault;
+
+		flags |= FAULT_FLAG_USER;
+
+		vma = find_vma(current->mm, va);
+		if (!vma || (va < vma->vm_start)) {
+			printk("%s: couldn't find VMA for va %lx\n", __FUNCTION__, va); 
+			error = -EINVAL;
+			goto out_release;
+		}
+
+		fault = handle_mm_fault(current->mm, vma, va, flags);
+		if (fault != 0) {
+			printk("%s: error: faulting %lx at off: %lu\n", 
+					__FUNCTION__, va, off);
+		}
+
+		page_fault_attempted = 1;
+		goto retry;
+	}
+
+out_release:
 	up_read(&current->mm->mmap_sem);
 
 	phys = ihk_device_map_memory(dev, ppfn_rpa, sizeof(*ppfn));
diff --git a/kernel/devobj.c b/kernel/devobj.c
index fdf68241..6d4ba3d7 100644
--- a/kernel/devobj.c
+++ b/kernel/devobj.c
@@ -79,7 +79,7 @@ static struct memobj *to_memobj(struct devobj *devobj)
  * devobj
  */
 int devobj_create(int fd, size_t len, off_t off, struct memobj **objp, int *maxprotp,
-	int prot)
+	int prot, int populate_flags)
 {
 	ihk_mc_user_context_t ctx;
 	struct pager_map_result result;	// XXX: assumes contiguous physical
@@ -116,7 +116,7 @@ int devobj_create(int fd, size_t len, off_t off, struct memobj **objp, int *maxp
 	ihk_mc_syscall_arg2(&ctx) = len;
 	ihk_mc_syscall_arg3(&ctx) = off;
 	ihk_mc_syscall_arg4(&ctx) = virt_to_phys(&result);
-	ihk_mc_syscall_arg5(&ctx) = prot;
+	ihk_mc_syscall_arg5(&ctx) = prot | populate_flags;
 
 	error = syscall_generic_forwarding(__NR_mmap, &ctx);
 	if (error) {
@@ -206,7 +206,7 @@ static void devobj_release(struct memobj *memobj)
 
 static int devobj_get_page(struct memobj *memobj, off_t off, int p2align, uintptr_t *physp, unsigned long *flag)
 {
-	const off_t pgoff = off >> PAGE_SHIFT;
+	const off_t pgoff = off / PAGE_SIZE;
 	struct devobj *obj = to_devobj(memobj);
 	int error;
 	uintptr_t pfn;
@@ -218,7 +218,7 @@ static int devobj_get_page(struct memobj *memobj, off_t off, int p2align, uintpt
 
 	if ((pgoff < obj->pfn_pgoff) || ((obj->pfn_pgoff + obj->npages) <= pgoff)) {
 		error = -EFBIG;
-		kprintf("devobj_get_page(%p %lx,%lx,%d): out of range. %d\n", memobj, obj->handle, off, p2align, error);
+		kprintf("%s: error: out of range: off: %lu, page off: %lu obj->npages: %d\n", __FUNCTION__, off, pgoff, obj->npages);
 		goto out;
 	}
 	ix = pgoff - obj->pfn_pgoff;
diff --git a/kernel/fileobj.c b/kernel/fileobj.c
index 09052036..05beccf4 100644
--- a/kernel/fileobj.c
+++ b/kernel/fileobj.c
@@ -182,7 +182,7 @@ int fileobj_create(int fd, struct memobj **objp, int *maxprotp)
 
 	error = syscall_generic_forwarding(__NR_mmap, &ctx);
 	if (error) {
-		kprintf("fileobj_create(%d):create failed. %d\n", fd, error);
+		dkprintf("fileobj_create(%d):create failed. %d\n", fd, error);
 		goto out;
 	}
 
diff --git a/kernel/include/memobj.h b/kernel/include/memobj.h
index 35e255eb..78fd7876 100644
--- a/kernel/include/memobj.h
+++ b/kernel/include/memobj.h
@@ -142,6 +142,6 @@ struct shmid_ds;
 int shmobj_create(struct shmid_ds *ds, struct memobj **objp);
 int zeroobj_create(struct memobj **objp);
 int devobj_create(int fd, size_t len, off_t off, struct memobj **objp, int *maxprotp,
-	int prot);
+	int prot, int populate_flags);
 
 #endif /* HEADER_MEMOBJ_H */
diff --git a/kernel/process.c b/kernel/process.c
index 8a783a97..baad39b9 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -1641,6 +1641,18 @@ static int do_page_fault_process_vm(struct process_vm *vm, void *fault_addr0, ui
 				"access denied. %d\n",
 				ihk_mc_get_processor_id(), vm,
 				fault_addr0, reason, error);
+		kprintf("%s: reason: %s%s%s%s%s%s%s%s\n", __FUNCTION__, 
+			(reason & PF_PROT) ? "PF_PROT " : "",
+			(reason & PF_WRITE) ? "PF_WRITE " : "",
+			(reason & PF_USER) ? "PF_USER " : "",
+			(reason & PF_RSVD) ? "PF_RSVD " : "",
+			(reason & PF_INSTR) ? "PF_INSTR " : "",
+			(reason & PF_PATCH) ? "PF_PATCH " : "",
+			(reason & PF_POPULATE) ? "PF_POPULATE " : "");
+		kprintf("%s: range->flag & (%s%s%s)\n", __FUNCTION__,
+			(range->flag & VR_PROT_READ) ? "VR_PROT_READ " : "",
+			(range->flag & VR_PROT_WRITE) ? "VR_PROT_WRITE " : "",
+			(range->flag & VR_PROT_EXEC) ? "VR_PROT_EXEC " : "");
 		if (((range->flag & VR_PROT_MASK) == VR_PROT_NONE))
 			kprintf("if (((range->flag & VR_PROT_MASK) == VR_PROT_NONE))\n");
 		if (((reason & PF_WRITE) && !(reason & PF_PATCH)))
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 3224f99c..062f5656 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -1097,7 +1097,7 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
 		}
 #endif
 		if (error == -ESRCH) {
-			kprintf("do_mmap:hit non VREG\n");
+			dkprintf("do_mmap:hit non VREG\n");
 			/*
 			 * XXX: temporary:
 			 *
@@ -1108,10 +1108,17 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
 				vrflags &= ~VR_MEMTYPE_MASK;
 				vrflags |= VR_MEMTYPE_UC;
 			}
-			error = devobj_create(fd, len, off, &memobj, &maxprot, prot);
+			error = devobj_create(fd, len, off, &memobj, &maxprot, 
+					prot, (flags & (MAP_POPULATE | MAP_LOCKED)));
+
+			if (!error) {
+				dkprintf("%s: device fd: %d off: %lu mapping at %p - %p\n", 
+						__FUNCTION__, fd, off, addr, addr + len); 
+			}
 		}
 		if (error) {
-			ekprintf("do_mmap:fileobj_create failed. %d\n", error);
+			kprintf("%s: error: file mapping failed, fd: %d, error: %d\n",
+					__FUNCTION__, error);
 			goto out;
 		}
 	}
@@ -1181,9 +1188,12 @@ out:
 	if (!error && populated_mapping) {
 		error = populate_process_memory(thread->vm, (void *)addr, len);
 		if (error) {
-			ekprintf("do_mmap:populate_process_memory"
-					"(%p,%p,%lx) failed %d\n",
-					thread->vm, (void *)addr, len, error);
+			ekprintf("%s: error :populate_process_memory"
+					"vm: %p, addr: %p, len: %d (flags: %s%s) failed %d\n", __FUNCTION__,
+					thread->vm, (void *)addr, len,
+					(flags & MAP_POPULATE) ? "MAP_POPULATE " : "",
+					(flags & MAP_LOCKED) ? "MAP_LOCKED ": "",
+					error);
 			/*
 			 * In this case,
 			 * the mapping established by this call should be unmapped
@@ -5574,7 +5584,7 @@ SYSCALL_DECLARE(sched_setaffinity)
 	len = MIN2(len, sizeof(k_cpu_set));
 
 	if (copy_from_user(&k_cpu_set, u_cpu_set, len)) {
-		kprintf("%s:%d copy_from_user failed.\n", __FILE__, __LINE__);
+		kprintf("%s: error: copy_from_user failed for %p:%d\n", __FUNCTION__, u_cpu_set, len);
 		return -EFAULT;
 	}