diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index fef2c5e09660..f7c330b0d3b7 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -467,9 +467,11 @@
 				    u_int nfds, int timeout); }
 253	AUE_NULL	MSTD	{ int issetugid(void); }
 254	AUE_NULL	MSTD	{ int lchown(char *path, int uid, int gid); }
-255	AUE_NULL	UNIMPL	nosys
-256	AUE_NULL	UNIMPL	nosys
-257	AUE_NULL	UNIMPL	nosys
+255	AUE_NULL	NOSTD	{ int aio_read(struct aiocb *aiocbp); }
+256	AUE_NULL	NOSTD	{ int aio_write(struct aiocb *aiocbp); }
+257	AUE_NULL	NOSTD	{ int lio_listio(int mode, \
+				    struct aiocb * const *acb_list, \
+				    int nent, struct sigevent *sig); }
 258	AUE_NULL	UNIMPL	nosys
 259	AUE_NULL	UNIMPL	nosys
 260	AUE_NULL	UNIMPL	nosys
@@ -551,11 +553,11 @@
 316	AUE_NULL	NOSTD	{ int aio_cancel(int fd, \
 				    struct aiocb *aiocbp); }
 317	AUE_NULL	NOSTD	{ int aio_error(struct aiocb *aiocbp); }
-318	AUE_NULL	NOSTD	{ int aio_read(struct aiocb *aiocbp); }
-319	AUE_NULL	NOSTD	{ int aio_write(struct aiocb *aiocbp); }
-320	AUE_NULL	NOSTD	{ int lio_listio(int mode, \
-				    struct aiocb * const *acb_list, \
-				    int nent, struct sigevent *sig); }
+318	AUE_NULL	NOSTD	{ int oaio_read(struct oaiocb *aiocbp); }
+319	AUE_NULL	NOSTD	{ int oaio_write(struct oaiocb *aiocbp); }
+320	AUE_NULL	NOSTD	{ int olio_listio(int mode, \
+				    struct oaiocb * const *acb_list, \
+				    int nent, struct osigevent *sig); }
 321	AUE_NULL	MSTD	{ int yield(void); }
 322	AUE_NULL	OBSOL	thr_sleep
 323	AUE_NULL	OBSOL	thr_wakeup
diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index 2d550da7d0c6..007d1ed246cb 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -170,6 +170,17 @@ static int max_buf_aio = MAX_BUF_AIO;
 SYSCTL_INT(_vfs_aio, OID_AUTO, max_buf_aio, CTLFLAG_RW, &max_buf_aio, 0,
     "Maximum buf aio requests per process (stored in the process)");
 
+typedef struct oaiocb {
+	int	aio_fildes;		/* File descriptor */
+	off_t	aio_offset;		/* File offset for I/O */
+	volatile void *aio_buf;         /* I/O buffer in process space */
+	size_t	aio_nbytes;		/* Number of bytes for I/O */
+	struct	osigevent aio_sigevent;	/* Signal to deliver */
+	int	aio_lio_opcode;		/* LIO opcode */
+	int	aio_reqprio;		/* Request priority -- ignored */
+	struct	__aiocb_private	_aiocb_private;
+} oaiocb_t;
+
 struct aiocblist {
 	TAILQ_ENTRY(aiocblist) list;	/* List of jobs */
 	TAILQ_ENTRY(aiocblist) plist;	/* List of jobs for proc */
@@ -254,7 +265,8 @@ static void	aio_onceonly(void);
 static int	aio_free_entry(struct aiocblist *aiocbe);
 static void	aio_process(struct aiocblist *aiocbe);
 static int	aio_newproc(void);
-static int	aio_aqueue(struct thread *td, struct aiocb *job, int type);
+static int	aio_aqueue(struct thread *td, struct aiocb *job, int type,
+			int osigev);
 static void	aio_physwakeup(struct buf *bp);
 static void	aio_proc_rundown(void *arg, struct proc *p);
 static int	aio_fphysio(struct aiocblist *aiocbe);
@@ -271,6 +283,8 @@ static int	filt_lio(struct knote *kn, long hint);
 #define DONE_BUF 1
 #define DONE_QUEUE 2
 static void	aio_bio_done_notify( struct proc *userp, struct aiocblist *aiocbe, int type);
+static int	do_lio_listio(struct thread *td, struct lio_listio_args *uap,
+			int oldsigev);
 
 /*
  * Zones for:
@@ -328,6 +342,9 @@ SYSCALL_MODULE_HELPER(aio_read);
 SYSCALL_MODULE_HELPER(aio_write);
 SYSCALL_MODULE_HELPER(aio_waitcomplete);
 SYSCALL_MODULE_HELPER(lio_listio);
+SYSCALL_MODULE_HELPER(oaio_read);
+SYSCALL_MODULE_HELPER(oaio_write);
+SYSCALL_MODULE_HELPER(olio_listio);
 
 DECLARE_MODULE(aio, aio_mod,
 	SI_SUB_VFS, SI_ORDER_ANY);
@@ -1320,7 +1337,8 @@ aio_swake_cb(struct socket *so, struct sockbuf *sb)
  * technique is done in this code.
  */
 static int
-_aio_aqueue(struct thread *td, struct aiocb *job, struct aio_liojob *lj, int type)
+_aio_aqueue(struct thread *td, struct aiocb *job, struct aio_liojob *lj,
+	int type, int oldsigev)
 {
 	struct proc *p = td->td_proc;
 	struct filedesc *fdp;
@@ -1348,7 +1366,14 @@ _aio_aqueue(struct thread *td, struct aiocb *job, struct aio_liojob *lj, int typ
 	suword(&job->_aiocb_private.error, 0);
 	suword(&job->_aiocb_private.kernelinfo, -1);
 
-	error = copyin(job, &aiocbe->uaiocb, sizeof(aiocbe->uaiocb));
+	if (oldsigev) {
+		bzero(&aiocbe->uaiocb, sizeof(struct aiocb));
+		error = copyin(job, &aiocbe->uaiocb, sizeof(struct oaiocb));
+		bcopy(&aiocbe->uaiocb.__spare__, &aiocbe->uaiocb.aio_sigevent,
+			sizeof(struct osigevent));
+	} else {
+		error = copyin(job, &aiocbe->uaiocb, sizeof(struct aiocb));
+	}
 	if (error) {
 		suword(&job->_aiocb_private.error, error);
 		uma_zfree(aiocb_zone, aiocbe);
@@ -1558,7 +1583,7 @@ done:
  * This routine queues an AIO request, checking for quotas.
  */
 static int
-aio_aqueue(struct thread *td, struct aiocb *job, int type)
+aio_aqueue(struct thread *td, struct aiocb *job, int type, int oldsigev)
 {
 	struct proc *p = td->td_proc;
 	struct kaioinfo *ki;
@@ -1573,7 +1598,7 @@ aio_aqueue(struct thread *td, struct aiocb *job, int type)
 	if (ki->kaio_queue_count >= ki->kaio_qallowed_count)
 		return (EAGAIN);
 
-	return _aio_aqueue(td, job, NULL, type);
+	return _aio_aqueue(td, job, NULL, type, oldsigev);
 }
 
 /*
@@ -1956,24 +1981,51 @@ aio_error(struct thread *td, struct aio_error_args *uap)
 }
 
 /* syscall - asynchronous read from a file (REALTIME) */
+int
+oaio_read(struct thread *td, struct oaio_read_args *uap)
+{
+
+	return aio_aqueue(td, (struct aiocb *)uap->aiocbp, LIO_READ, 1);
+}
+
 int
 aio_read(struct thread *td, struct aio_read_args *uap)
 {
 
-	return aio_aqueue(td, uap->aiocbp, LIO_READ);
+	return aio_aqueue(td, uap->aiocbp, LIO_READ, 0);
 }
 
 /* syscall - asynchronous write to a file (REALTIME) */
+int
+oaio_write(struct thread *td, struct oaio_write_args *uap)
+{
+
+	return aio_aqueue(td, (struct aiocb *)uap->aiocbp, LIO_WRITE, 1);
+}
+
 int
 aio_write(struct thread *td, struct aio_write_args *uap)
 {
 
-	return aio_aqueue(td, uap->aiocbp, LIO_WRITE);
+	return aio_aqueue(td, uap->aiocbp, LIO_WRITE, 0);
+}
+
+/* syscall - list directed I/O (REALTIME) */
+int
+olio_listio(struct thread *td, struct olio_listio_args *uap)
+{
+	return do_lio_listio(td, (struct lio_listio_args *)uap, 1);
 }
 
 /* syscall - list directed I/O (REALTIME) */
 int
 lio_listio(struct thread *td, struct lio_listio_args *uap)
+{
+	return do_lio_listio(td, uap, 0);
+}
+
+static int
+do_lio_listio(struct thread *td, struct lio_listio_args *uap, int oldsigev)
 {
 	struct proc *p = td->td_proc;
 	int nent, nentqueued;
@@ -2023,8 +2075,10 @@ lio_listio(struct thread *td, struct lio_listio_args *uap)
 	 * Setup signal.
 	 */
 	if (uap->sig && (uap->mode == LIO_NOWAIT)) {
+		bzero(&lj->lioj_signal, sizeof(&lj->lioj_signal));
 		error = copyin(uap->sig, &lj->lioj_signal,
-		    sizeof(lj->lioj_signal));
+				oldsigev ? sizeof(struct osigevent) :
+					   sizeof(struct sigevent));
 		if (error) {
 			uma_zfree(aiolio_zone, lj);
 			return (error);
@@ -2071,7 +2125,7 @@ lio_listio(struct thread *td, struct lio_listio_args *uap)
 	for (i = 0; i < uap->nent; i++) {
 		iocb = (struct aiocb *)(intptr_t)fuword(&cbptr[i]);
 		if (((intptr_t)iocb != -1) && ((intptr_t)iocb != 0)) {
-			error = _aio_aqueue(td, iocb, lj, 0);
+			error = _aio_aqueue(td, iocb, lj, 0, oldsigev);
 			if (error == 0)
 				nentqueued++;
 			else
diff --git a/sys/sys/aio.h b/sys/sys/aio.h
index f0c2a11576ed..1b09e490ecee 100644
--- a/sys/sys/aio.h
+++ b/sys/sys/aio.h
@@ -66,10 +66,11 @@ typedef struct aiocb {
 	off_t	aio_offset;		/* File offset for I/O */
 	volatile void *aio_buf;         /* I/O buffer in process space */
 	size_t	aio_nbytes;		/* Number of bytes for I/O */
-	struct	sigevent aio_sigevent;	/* Signal to deliver */
+	char 	__spare__[sizeof(int) * 2 + sizeof(void *)]; /* osigevent. */
 	int	aio_lio_opcode;		/* LIO opcode */
 	int	aio_reqprio;		/* Request priority -- ignored */
 	struct	__aiocb_private	_aiocb_private;
+	struct	sigevent aio_sigevent;	/* Signal to deliver */
 } aiocb_t;
 
 #ifndef _KERNEL
diff --git a/sys/sys/signal.h b/sys/sys/signal.h
index 7e273e30dd50..d6dc895e71da 100644
--- a/sys/sys/signal.h
+++ b/sys/sys/signal.h
@@ -158,28 +158,31 @@ union sigval {
 #if __POSIX_VISIBLE >= 199309
 struct sigevent {
 	int	sigev_notify;		/* Notification type */
-	union {
-		int	__sigev_signo;	/* Signal number */
-		int	__sigev_notify_kqueue;
-	} __sigev_u;
+	int	sigev_signo;		/* Signal number */
 	union sigval sigev_value;	/* Signal value */
-/*
- * XXX missing sigev_notify_function, sigev_notify_attributes.
- */
+	union {
+		__lwpid_t	_threadid;
+		struct {
+			void (*_function)(union sigval *);
+			void *_attribute; /* pthread_attr_t * */
+		} _sigev_thread;
+	} _sigev_un;
 };
-#define	sigev_signo		__sigev_u.__sigev_signo
-#if __BSD_VISIBLE
-#define	sigev_notify_kqueue	__sigev_u.__sigev_notify_kqueue
-#endif
 
-#define	SIGEV_NONE	0		/* No async notification */
-#define	SIGEV_SIGNAL	1		/* Generate a queued signal */
 #if __BSD_VISIBLE
-#define	SIGEV_KEVENT	3		/* Generate a kevent */
+#define	sigev_notify_kqueue		sigev_signo
+#define	sigev_notify_thread_id		_sigev_un._threadid
+#endif
+#define	sigev_notify_function		_sigev_un._sigev_thread._function
+#define	sigev_notify_attributes		_sigev_un._sigev_thread._attribute
+
+#define	SIGEV_NONE	0		/* No async notification. */
+#define	SIGEV_SIGNAL	1		/* Generate a queued signal. */
+#define	SIGEV_THREAD	2		/* Call back from another pthread. */
+#if __BSD_VISIBLE
+#define	SIGEV_KEVENT	3		/* Generate a kevent. */
+#define	SIGEV_THREAD_ID	4		/* Send signal to a kernel thread. */
 #endif
-/*
- * XXX missing SIGEV_THREAD.
- */
 #endif /* __POSIX_VISIBLE >= 199309 */
 
 #if __POSIX_VISIBLE >= 199309 || __XSI_VISIBLE
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index 124ff970301d..cde9742dfcae 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -199,6 +199,15 @@ __sigseteq(sigset_t *set1, sigset_t *set2)
 	return (1);
 }
 
+struct osigevent {
+	int	sigev_notify;		/* Notification type */
+	union {
+		int	__sigev_signo;	/* Signal number */
+		int	__sigev_notify_kqueue;
+	} __sigev_u;
+	union sigval sigev_value;	/* Signal value */
+};
+
 typedef struct ksiginfo {
 	TAILQ_ENTRY(ksiginfo)	ksi_link;
 	siginfo_t		ksi_info;