diff --git a/executer/kernel/mcctrl/control.c b/executer/kernel/mcctrl/control.c
index b5f2af52..3261b26e 100644
--- a/executer/kernel/mcctrl/control.c
+++ b/executer/kernel/mcctrl/control.c
@@ -1214,6 +1214,7 @@ int mcexec_open_exec(ihk_os_t os, char * __user filename)
 		INIT_LIST_HEAD(&ppd->wq_req_list);
 		INIT_LIST_HEAD(&ppd->wq_list_exact);
 		init_waitqueue_head(&ppd->wq_prepare);
+		init_waitqueue_head(&ppd->wq_procfs);
 		spin_lock_init(&ppd->wq_list_lock);
 		memset(&ppd->cpu_set, 0, sizeof(cpumask_t));
 		ppd->ikc_target_cpu = 0;
diff --git a/executer/kernel/mcctrl/ikc.c b/executer/kernel/mcctrl/ikc.c
index f8cf86f6..461a23be 100644
--- a/executer/kernel/mcctrl/ikc.c
+++ b/executer/kernel/mcctrl/ikc.c
@@ -80,7 +80,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 		break;
 
 	case SCD_MSG_PROCFS_ANSWER:
-		procfs_answer(pisp->arg, pisp->err);
+		procfs_answer(usrdata, pisp->pid);
 		break;
 
 	case SCD_MSG_SEND_SIGNAL:
@@ -288,6 +288,7 @@ int prepare_ikc_channels(ihk_os_t os)
 	ihk_ikc_listen_port(os, &usrdata->listen_param);
 	memcpy(&usrdata->listen_param2, &listen_param2, sizeof listen_param2);
 	ihk_ikc_listen_port(os, &usrdata->listen_param2);
+	init_waitqueue_head(&usrdata->wq_procfs);
 
 	for (i = 0; i < MCCTRL_PER_PROC_DATA_HASH_SIZE; ++i) {
 		INIT_LIST_HEAD(&usrdata->per_proc_data_hash[i]);
diff --git a/executer/kernel/mcctrl/mcctrl.h b/executer/kernel/mcctrl/mcctrl.h
index 63020009..09aca82e 100644
--- a/executer/kernel/mcctrl/mcctrl.h
+++ b/executer/kernel/mcctrl/mcctrl.h
@@ -197,6 +197,7 @@ struct mcctrl_per_proc_data {
 	struct list_head wq_list_exact;
 	ihk_spinlock_t wq_list_lock;
 	wait_queue_head_t wq_prepare;
+	wait_queue_head_t wq_procfs;
 
 	struct list_head per_thread_data_hash[MCCTRL_PER_THREAD_DATA_HASH_SIZE];
 	rwlock_t per_thread_data_hash_lock[MCCTRL_PER_THREAD_DATA_HASH_SIZE];
@@ -283,7 +284,7 @@ struct mcctrl_usrdata {
 	int	job_pos;
 	int	mcctrl_dma_abort;
 	unsigned long	last_thread_exec;
-	
+	wait_queue_head_t wq_procfs;
 	struct list_head per_proc_data_hash[MCCTRL_PER_PROC_DATA_HASH_SIZE];
 	rwlock_t per_proc_data_hash_lock[MCCTRL_PER_PROC_DATA_HASH_SIZE];
 
@@ -351,7 +352,7 @@ struct procfs_file {
 	char fname[PROCFS_NAME_MAX];	/* procfs filename (request) */
 };
 
-void procfs_answer(unsigned int arg, int err);
+void procfs_answer(struct mcctrl_usrdata *ud, int pid);
 int procfsm_packet_handler(void *os, int msg, int pid, unsigned long arg);
 void add_tid_entry(int osnum, int pid, int tid);
 void add_pid_entry(int osnum, int pid);
diff --git a/executer/kernel/mcctrl/procfs.c b/executer/kernel/mcctrl/procfs.c
index bee5483c..98058a1d 100644
--- a/executer/kernel/mcctrl/procfs.c
+++ b/executer/kernel/mcctrl/procfs.c
@@ -59,7 +59,6 @@ static const struct procfs_entry base_entry_stuff[];
 static const struct file_operations mckernel_forward_ro;
 static const struct file_operations mckernel_forward;
 
-static DECLARE_WAIT_QUEUE_HEAD(procfsq);
 static ssize_t mckernel_procfs_read(struct file *file, char __user *buf, 
 		size_t nbytes, loff_t *ppos);
 
@@ -106,14 +105,28 @@ getpath(struct procfs_list_entry *e, char *buf, int bufsize)
 /**
  * \brief Process SCD_MSG_PROCFS_ANSWER message.
  *
- * \param arg sent argument
- * \param err error info (redundant)
+ * \param ud mcctrl_usrdata pointer
+ * \param pid PID of the requesting process
  */
-void
-procfs_answer(unsigned int arg, int err)
+void procfs_answer(struct mcctrl_usrdata *ud, int pid)
 {
-	dprintk("procfs: received SCD_MSG_PROCFS_ANSWER message(err = %d).\n", err);
-	wake_up_interruptible(&procfsq);
+	struct mcctrl_per_proc_data *ppd = NULL;
+
+	if (pid > 0) {
+		ppd = mcctrl_get_per_proc_data(ud, pid);
+
+		if (unlikely(!ppd)) {
+			kprintf("%s: ERROR: no per-process structure for PID %d\n",
+					__FUNCTION__, pid);
+			return;
+		}
+	}
+
+	wake_up_all(pid > 0 ? &ppd->wq_procfs : &ud->wq_procfs);
+
+	if (pid > 0) {
+		mcctrl_put_per_proc_data(ppd);
+	}
 }
 
 static struct procfs_list_entry *
@@ -495,36 +508,84 @@ procfs_exit(int osnum)
  * This function conforms to the 2) way of fs/proc/generic.c
  * from linux-2.6.39.4.
  */
-static ssize_t
-mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
-	       loff_t *ppos)
+static ssize_t __mckernel_procfs_read_write(
+		struct file *file,
+		char __user *buf, size_t nbytes,
+		loff_t *ppos, int read_write)
 {
 	struct inode * inode = file->f_inode;
 	char *kern_buffer = NULL;
 	int order = 0;
 	volatile struct procfs_read *r = NULL;
 	struct ikc_scd_packet isp;
-	int ret;
+	int ret, osnum, pid, retw;
 	unsigned long pbuf;
 	unsigned long count = nbytes;
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,10,0)
 	struct proc_dir_entry *dp = PDE(inode);
 	struct procfs_list_entry *e = dp->data;
-#else	
+#else
 	struct procfs_list_entry *e = PDE_DATA(inode);
-#endif	
+#endif
 	loff_t offset = *ppos;
 	char pathbuf[PROCFS_NAME_MAX];
-	char *path;
+	char *path, *p;
+	ihk_os_t os = NULL;
+	struct mcctrl_usrdata *udp = NULL;
+	struct mcctrl_per_proc_data *ppd = NULL;
 
-	path = getpath(e, pathbuf, 256);
-	dprintk("mckernel_procfs_read: invoked for %s, offset: %lu, count: %d\n", 
-			path, offset, count); 
-	
 	if (count <= 0 || offset < 0) {
 		return 0;
 	}
-	
+
+	path = getpath(e, pathbuf, PROCFS_NAME_MAX);
+	dprintk("%s: invoked for %s, offset: %lu, count: %lu\n",
+			__FUNCTION__, path,
+			(unsigned long)offset, count);
+
+	/* Verify OS number */
+	ret = sscanf(path, "mcos%d/", &osnum);
+	if (ret != 1) {
+		printk("%s: error: couldn't determine OS number\n", __FUNCTION__);
+		return -EINVAL;
+	}
+
+	if (osnum != e->osnum) {
+		printk("%s: error: OS numbers don't match\n", __FUNCTION__);
+		return -EINVAL;
+	}
+
+	/* Is this request for a specific process? */
+	p = strchr(path, '/') + 1;
+	ret = sscanf(p, "%d/", &pid);
+	if (ret != 1) {
+		pid = -1;
+	}
+
+	os = osnum_to_os(osnum);
+	if (!os) {
+		printk("%s: error: no IHK OS data found for OS %d\n",
+				__FUNCTION__, osnum);
+		return -EINVAL;
+	}
+
+	udp = ihk_host_os_get_usrdata(os);
+	if (!udp) {
+		printk("%s: error: no MCCTRL data found for OS %d\n",
+				__FUNCTION__, osnum);
+		return -EINVAL;
+	}
+
+	if (pid > 0) {
+		ppd = mcctrl_get_per_proc_data(udp, pid);
+
+		if (unlikely(!ppd)) {
+			printk("%s: error: no per-process structure for PID %d",
+					__FUNCTION__, pid);
+			return -EINVAL;
+		}
+	}
+
 	while ((1 << order) < count) ++order;
 	if (order > 12) {
 		order -= 12;
@@ -536,10 +597,11 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
 	/* NOTE: we need physically contigous memory to pass through IKC */
 	kern_buffer = (char *)__get_free_pages(GFP_KERNEL, order);
 	if (!kern_buffer) {
-		printk("mckernel_procfs_read(): ERROR: allocating kernel buffer\n");
-		return -ENOMEM;
+		printk("%s: ERROR: allocating kernel buffer\n", __FUNCTION__);
+		ret = -ENOMEM;
+		goto out;
 	}
-	
+
 	pbuf = virt_to_phys(kern_buffer);
 
 	r = kmalloc(sizeof(struct procfs_read), GFP_KERNEL);
@@ -553,152 +615,96 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
 	r->status = 0;
 	r->offset = offset;
 	r->count = count;
-	r->readwrite = 0;
+	r->readwrite = read_write;
 	strncpy((char *)r->fname, path, PROCFS_NAME_MAX);
 	isp.msg = SCD_MSG_PROCFS_REQUEST;
 	isp.ref = 0;
 	isp.arg = virt_to_phys(r);
-	
-	ret = mcctrl_ikc_send(osnum_to_os(e->osnum), 0, &isp);
-	
+	isp.pid = pid;
+
+	ret = mcctrl_ikc_send(osnum_to_os(e->osnum),
+			(pid > 0) ? ppd->ikc_target_cpu : 0, &isp);
+
 	if (ret < 0) {
 		goto out; /* error */
 	}
-	
+
 	/* Wait for a reply. */
 	ret = -EIO; /* default exit code */
-	dprintk("now wait for a relpy\n");
-	
-	/* Wait for the status field of the procfs_read structure set ready. */
-	if (wait_event_interruptible_timeout(procfsq, r->status != 0, HZ) == 0) {
-		kprintf("ERROR: mckernel_procfs_read: timeout (1 sec).\n");
+	dprintk("%s: waiting for reply\n", __FUNCTION__);
+
+retry_wait:
+	/* Wait for the status field of the procfs_read structure,
+	 * wait on per-process or OS specific data depending on
+	 * who the request is for.
+	 */
+	if (pid > 0) {
+		retw = wait_event_interruptible_timeout(ppd->wq_procfs,
+				r->status != 0, HZ);
+	}
+	else {
+		retw = wait_event_interruptible_timeout(udp->wq_procfs,
+				r->status != 0, HZ);
+	}
+
+	/* Timeout? */
+	if (retw == 0 && r->status == 0) {
+		printk("%s: error: timeout (1 sec)\n", __FUNCTION__);
 		goto out;
 	}
-	
-	/* Wake up and check the result. */
-	dprintk("mckernel_procfs_read: woke up. ret: %d, eof: %d\n", r->ret, r->eof);
-	
-	if (r->ret > 0) {
-		if (copy_to_user(buf, kern_buffer, r->ret)) {
-			kprintf("ERROR: mckernel_procfs_read: copy_to_user failed.\n");
-			ret = -EFAULT;
-			goto out;
-		}
+	/* Interrupted? */
+	else if (retw == -ERESTARTSYS) {
+		ret = -ERESTART;
+		goto out;
+	}
+	/* Were we woken up by a reply to another procfs request? */
+	else if (r->status == 0) {
+		/* TODO: r->status is not set atomically, we could be woken
+		 * up with status == 0 and it could change to 1 while in this
+		 * code, we could potentially miss the wake_up()... 
+		 */
+		printk("%s: stale wake-up, retrying\n", __FUNCTION__);
+		goto retry_wait;
+	}
 
+	/* Wake up and check the result. */
+	dprintk("%s: woke up. ret: %d, eof: %d\n",
+			__FUNCTION__, r->ret, r->eof);
+
+	if (r->ret > 0) {
+		if (read_write == 0) {
+			if (copy_to_user(buf, kern_buffer, r->ret)) {
+				printk("%s: ERROR: copy_to_user failed.\n", __FUNCTION__);
+				ret = -EFAULT;
+				goto out;
+			}
+		}
 		*ppos += r->ret;
 	}
 	ret = r->ret;
 
 out:
-	if(kern_buffer)
+	if (ppd)
+		mcctrl_put_per_proc_data(ppd);
+	if (kern_buffer)
 		free_pages((uintptr_t)kern_buffer, order);
-	if(r)
+	if (r)
 		kfree((void *)r);
-	
+
 	return ret;
 }
 
-static ssize_t
-mckernel_procfs_write(struct file *file, const char __user *buf, size_t nbytes,
-	       loff_t *ppos)
+static ssize_t mckernel_procfs_read(struct file *file,
+		char __user *buf, size_t nbytes, loff_t *ppos)
 {
-	struct inode * inode = file->f_inode;
-	char *kern_buffer = NULL;
-	int order = 0;
-	volatile struct procfs_read *r = NULL;
-	struct ikc_scd_packet isp;
-	int ret;
-	unsigned long pbuf;
-	unsigned long count = nbytes;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,10,0)
-	struct proc_dir_entry *dp = PDE(inode);
-	struct procfs_list_entry *e = dp->data;
-#else	
-	struct procfs_list_entry *e = PDE_DATA(inode);
-#endif	
-	loff_t offset = *ppos;
-	char pathbuf[PROCFS_NAME_MAX];
-	char *path;
+	return __mckernel_procfs_read_write(file, buf, nbytes, ppos, 0);
+}
 
-	path = getpath(e, pathbuf, 256);
-	dprintk("mckernel_procfs_read: invoked for %s, offset: %lu, count: %d\n", 
-			path, offset, count); 
-	
-	if (count <= 0 || offset < 0) {
-		return 0;
-	}
-	
-	while ((1 << order) < count) ++order;
-	if (order > 12) {
-		order -= 12;
-	}
-	else {
-		order = 1;
-	}
-
-	/* NOTE: we need physically contigous memory to pass through IKC */
-	kern_buffer = (char *)__get_free_pages(GFP_KERNEL, order);
-	if (!kern_buffer) {
-		printk("mckernel_procfs_read(): ERROR: allocating kernel buffer\n");
-		return -ENOMEM;
-	}
-	if (copy_from_user(kern_buffer, buf, nbytes)) {
-		ret = -EFAULT;
-		goto out;
-	}
-	
-	pbuf = virt_to_phys(kern_buffer);
-
-	r = kmalloc(sizeof(struct procfs_read), GFP_KERNEL);
-	if (r == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	dprintk("offset: %lx, count: %d, cpu: %d\n", offset, count, e->cpu);
-
-	r->pbuf = pbuf;
-	r->eof = 0;
-	r->ret = -EIO; /* default */
-	r->status = 0;
-	r->offset = offset;
-	r->count = count;
-	r->readwrite = 1;
-	strncpy((char *)r->fname, path, PROCFS_NAME_MAX);
-	isp.msg = SCD_MSG_PROCFS_REQUEST;
-	isp.ref = 0;
-	isp.arg = virt_to_phys(r);
-	
-	ret = mcctrl_ikc_send(osnum_to_os(e->osnum), 0, &isp);
-	
-	if (ret < 0) {
-		goto out; /* error */
-	}
-	
-	/* Wait for a reply. */
-	ret = -EIO; /* default exit code */
-	dprintk("now wait for a relpy\n");
-	
-	/* Wait for the status field of the procfs_read structure set ready. */
-	if (wait_event_interruptible_timeout(procfsq, r->status != 0, HZ) == 0) {
-		kprintf("ERROR: mckernel_procfs_read: timeout (1 sec).\n");
-		goto out;
-	}
-	
-	/* Wake up and check the result. */
-	dprintk("mckernel_procfs_read: woke up. ret: %d, eof: %d\n", r->ret, r->eof);
-	
-	if (r->ret > 0) {
-		*ppos += r->ret;
-	}
-	ret = r->ret;
-
-out:
-	if(kern_buffer)
-		free_pages((uintptr_t)kern_buffer, order);
-	if(r)
-		kfree((void *)r);
-	
-	return ret;
+static ssize_t mckernel_procfs_write(struct file *file,
+		const char __user *buf, size_t nbytes, loff_t *ppos)
+{
+	return __mckernel_procfs_read_write(file,
+			(char __user *)buf, nbytes, ppos, 1);
 }
 
 static loff_t
diff --git a/kernel/host.c b/kernel/host.c
index e2a6ad70..c1092026 100644
--- a/kernel/host.c
+++ b/kernel/host.c
@@ -532,7 +532,7 @@ static void syscall_channel_send(struct ihk_ikc_channel_desc *c,
 }
 
 extern unsigned long do_kill(struct thread *, int, int, int, struct siginfo *, int ptracecont);
-extern void process_procfs_request(unsigned long rarg);
+extern void process_procfs_request(struct ikc_scd_packet *rpacket);
 extern void terminate_host(int pid);
 extern void debug_log(long);
 
@@ -640,7 +640,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 		break;
 
 	case SCD_MSG_PROCFS_REQUEST:
-		process_procfs_request(packet->arg);
+		process_procfs_request(packet);
 		ret = 0;
 		break;
 
diff --git a/kernel/procfs.c b/kernel/procfs.c
index f5ad271c..133edc89 100644
--- a/kernel/procfs.c
+++ b/kernel/procfs.c
@@ -76,11 +76,11 @@ procfs_delete_thread(struct thread *thread)
  *
  * \param rarg returned argument
  */
-void
-process_procfs_request(unsigned long rarg)
+void process_procfs_request(struct ikc_scd_packet *rpacket)
 {
+	unsigned long rarg = rpacket->arg;
 	unsigned long parg, pbuf;
-        struct thread *thread = NULL;
+	struct thread *thread = NULL;
 	struct process *proc = NULL;
 	struct process_vm *vm = NULL;
 	struct procfs_read *r;
@@ -633,6 +633,7 @@ dataunavail:
 
 	packet.msg = SCD_MSG_PROCFS_ANSWER;
 	packet.arg = rarg;
+	packet.pid = rpacket->pid;
 
 	ret = ihk_ikc_send(syscall_channel, &packet, 0);
 	if (ret < 0) {