Index: test/arch/um/drivers/ubd_kern.c
===================================================================
--- test.orig/arch/um/drivers/ubd_kern.c	2005-09-27 12:02:19.000000000 -0400
+++ test/arch/um/drivers/ubd_kern.c	2005-09-27 12:03:00.000000000 -0400
@@ -1081,7 +1081,7 @@
 		if(dev->end_sg == 0){
 			struct request *req = elv_next_request(q);
 			if(req == NULL)
-				return;
+				goto out;
 
 			dev->request = req;
 			blkdev_dequeue_request(req);
@@ -1103,7 +1103,7 @@
 			if(do_io(&io_req, req, dev->cow.bitmap) == -EAGAIN){
 				if(list_empty(&dev->restart))
 					list_add(&dev->restart, &restart);
-				return;
+				goto out;
 			}
 
 			req->sector += sg->length >> 9;
@@ -1112,6 +1112,8 @@
 		dev->end_sg = 0;
 		dev->request = NULL;
 	}
+out:
+	finish_aio();
 }
 
 static int ubd_ioctl(struct inode * inode, struct file * file,
Index: test/arch/um/include/aio.h
===================================================================
--- test.orig/arch/um/include/aio.h	2005-09-27 11:33:43.000000000 -0400
+++ test/arch/um/include/aio.h	2005-09-27 12:03:00.000000000 -0400
@@ -36,5 +36,6 @@
 			   .next	= NULL }
 
 extern int submit_aio(struct aio_context *aio);
+extern int finish_aio(void);
 
 #endif
Index: test/arch/um/os-Linux/aio.c
===================================================================
--- test.orig/arch/um/os-Linux/aio.c	2005-09-27 12:02:42.000000000 -0400
+++ test/arch/um/os-Linux/aio.c	2005-09-27 12:03:00.000000000 -0400
@@ -80,6 +80,9 @@
  * that it now backs the mmapped area.
  */
 
+/* XXX Fix for SMP */
+static int pending_events;
+
 static int do_aio(aio_context_t ctx, struct aio_context *aio)
 {
         struct iocb iocb, *iocbp = &iocb;
@@ -115,8 +118,10 @@
         }
 
         err = io_submit(ctx, 1, &iocbp);
-        if(err > 0)
+        if(err > 0){
                 err = 0;
+		pending_events++;
+	}
 	else
 		err = -errno;
 
@@ -124,6 +129,21 @@
         return err;
 }
 
+static int aio_wakeup_r_fd;
+static int aio_wakeup_w_fd;
+
+static int finish_aio_26(void)
+{
+	int err;
+
+	err = write(aio_wakeup_w_fd, &pending_events, sizeof(pending_events));
+	err = (err != sizeof(pending_events)) ? errno : 0;
+
+	pending_events = 0;
+
+	return err;
+}
+
 static aio_context_t ctx = 0;
 
 static int aio_thread(void *arg)
@@ -131,35 +151,44 @@
         struct aio_thread_reply reply;
         struct aio_context *aio;
         struct io_event event;
-        int err, n;
+        int err, i, n, nevents;
 
         signal(SIGWINCH, SIG_IGN);
 
         while(1){
-                n = io_getevents(ctx, 1, 1, &event, NULL);
-                if(n < 0){
-                        if(errno == EINTR)
-                                continue;
-                        printk("aio_thread - io_getevents failed, "
-                               "errno = %d\n", errno);
-                }
-                else {
-			aio = (struct aio_context *) (long) event.data;
-			if(update_aio(aio, event.res)){
-				do_aio(ctx, aio);
-				continue;
+		n = read(aio_wakeup_r_fd, &nevents, sizeof(nevents));
+		if(n != sizeof(nevents)){
+			   printk("aio_thread - reading wakeup fd returned "
+				  "%d, errno = %d\n", n, errno);
+			   continue;
+		}
+
+		for(i = 0; i < nevents; i++){
+			n = io_getevents(ctx, 1, 1, &event, NULL);
+			if(n < 0){
+				if(errno == EINTR)
+					continue;
+				printk("aio_thread - io_getevents failed, "
+				       "errno = %d\n", errno);
 			}
-
-                        reply = ((struct aio_thread_reply)
-				{ .data = aio,
-				  .err	= aio->len });
-			err = os_write_file(aio->reply_fd, &reply,
-					    sizeof(reply));
-                        if(err != sizeof(reply))
-				printk("aio_thread - write failed, "
-				       "fd = %d, err = %d\n", aio->reply_fd,
-				       -err);
-                }
+			else {
+				aio = (struct aio_context *) (long) event.data;
+				if(update_aio(aio, event.res)){
+					do_aio(ctx, aio);
+					continue;
+				}
+
+				reply = ((struct aio_thread_reply)
+					{ .data = aio,
+							.err	= aio->len });
+				err = os_write_file(aio->reply_fd, &reply,
+						    sizeof(reply));
+				if(err != sizeof(reply))
+					printk("aio_thread - write failed, "
+					       "fd = %d, err = %d\n", 
+					       aio->reply_fd, -err);
+			}
+		}
         }
         return 0;
 }
@@ -251,6 +280,7 @@
 
 static int aio_pid = -1;
 static int (*submit_proc)(struct aio_context *aio);
+static int (*finish_proc)(void);
 
 static int init_aio_24(void)
 {
@@ -315,7 +345,7 @@
 static int init_aio_26(void)
 {
         unsigned long stack;
-        int err;
+        int err, wakeup_pipe[2];
 
         if(io_setup(256, &ctx)){
 		err = -errno;
@@ -324,10 +354,18 @@
 		goto out;
         }
 
+	if(pipe(wakeup_pipe) < 0){
+		err = -errno;
+		goto out;
+	}
+
+	aio_wakeup_r_fd = wakeup_pipe[0];
+	aio_wakeup_w_fd = wakeup_pipe[1];
+
         err = run_helper_thread(aio_thread, NULL,
                                 CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
         if(err < 0)
-		goto out;
+		goto out_close;
 
         aio_pid = err;
 	err = 0;
@@ -335,9 +373,15 @@
 	printk("Using 2.6 host AIO\n");
 
 	submit_proc = submit_aio_26;
+	finish_proc = finish_aio_26;
 
 out:
         return err;
+
+out_close:
+	close(wakeup_pipe[0]);
+	close(wakeup_pipe[1]);
+	goto out;
 }
 
 #else
@@ -350,6 +394,7 @@
 static int init_aio_26(void)
 {
 	submit_proc = submit_aio_26;
+	finish_proc = finish_aio_26;
         return -ENOSYS;
 }
 #endif
@@ -420,3 +465,11 @@
 {
 	return (*submit_proc)(aio);
 }
+
+int finish_aio(void)
+{
+	if(finish_proc == NULL)
+		return 0;
+
+	return (*finish_proc)();
+}