Index: external/cddl/osnet/dev/sdt/sdt.c
===================================================================
RCS file: /cvsroot/src/external/cddl/osnet/dev/sdt/sdt.c,v
retrieving revision 1.11
diff -p -u -r1.11 sdt.c
--- external/cddl/osnet/dev/sdt/sdt.c	26 Feb 2015 10:31:52 -0000	1.11
+++ external/cddl/osnet/dev/sdt/sdt.c	9 Mar 2015 04:36:01 -0000
@@ -89,6 +89,34 @@ static struct cdev		*sdt_cdev;
  */
 
 /*
+ * io provider
+ */
+
+SDT_PROBE_DECLARE(io,,,done);
+SDT_PROBE_DECLARE(io,,,start);
+SDT_PROBE_DECLARE(io,,,wait_done);
+SDT_PROBE_DECLARE(io,,,wait_start);
+
+static sdt_provider_t io_provider = {
+	.name = "io",
+	.id = 0,		/* set by dtrace_register */
+	.attr = {
+		{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
+		{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
+		{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
+		{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
+		{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
+	},
+	.probes = {
+		&SDT_NAME(io,,,done),
+		&SDT_NAME(io,,,start),
+		&SDT_NAME(io,,,wait_done),
+		&SDT_NAME(io,,,wait_start),
+		NULL
+	}
+};
+
+/*
  * proc provider
  */
 
@@ -136,6 +164,7 @@ static sdt_provider_t proc_provider = {
 
 /* list of local providers to register with DTrace */
 static sdt_provider_t *sdt_providers[] = {
+	&io_provider,
 	&proc_provider,
 	NULL		/* NULL terminated list */
 };
Index: sys/kern/subr_devsw.c
===================================================================
RCS file: /cvsroot/src/sys/kern/subr_devsw.c,v
retrieving revision 1.33
diff -p -u -r1.33 subr_devsw.c
--- sys/kern/subr_devsw.c	5 Sep 2014 05:57:21 -0000	1.33
+++ sys/kern/subr_devsw.c	9 Mar 2015 04:36:03 -0000
@@ -80,6 +80,7 @@ __KERNEL_RCSID(0, "$NetBSD: subr_devsw.c
 #include <sys/cpu.h>
 #include <sys/buf.h>
 #include <sys/reboot.h>
+#include <sys/sdt.h>
 
 #ifdef DEVSW_DEBUG
 #define	DPRINTF(x)	printf x
@@ -730,12 +731,21 @@ bdev_close(dev_t dev, int flag, int devt
 	return rv;
 }
 
+SDT_PROBE_DEFINE(io,,,start,start,
+    "struct buf *", NULL,	/* arg0: bp */
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL);
+
 void
 bdev_strategy(struct buf *bp)
 {
 	const struct bdevsw *d;
 	int mpflag;
 
+	SDT_PROBE(io,,,start, bp, NULL, NULL, NULL, NULL);
+
 	if ((d = bdevsw_lookup(bp->b_dev)) == NULL) {
 		bp->b_error = ENXIO;
 		bp->b_resid = bp->b_bcount;
Index: sys/kern/vfs_bio.c
===================================================================
RCS file: /cvsroot/src/sys/kern/vfs_bio.c,v
retrieving revision 1.252
diff -p -u -r1.252 vfs_bio.c
--- sys/kern/vfs_bio.c	8 Sep 2014 22:01:24 -0000	1.252
+++ sys/kern/vfs_bio.c	9 Mar 2015 04:36:03 -0000
@@ -144,6 +144,7 @@ __KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 
 #include <sys/wapbl.h>
 #include <sys/bitops.h>
 #include <sys/cprng.h>
+#include <sys/sdt.h>
 
 #include <uvm/uvm.h>	/* extern struct uvm uvm */
 
@@ -1475,6 +1476,19 @@ buf_drain(int n)
 	return size;
 }
 
+SDT_PROBE_DEFINE(io,,,wait_start,wait-start,
+    "struct buf *", NULL,	/* arg0: bp */
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL);
+SDT_PROBE_DEFINE(io,,,wait_done,wait-done,
+    "struct buf *", NULL,	/* arg0: bp */
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL);
+
 /*
  * Wait for operations on the buffer to complete.
  * When they do, extract and return the I/O's error value.
@@ -1486,11 +1500,15 @@ biowait(buf_t *bp)
 	KASSERT(ISSET(bp->b_cflags, BC_BUSY));
 	KASSERT(bp->b_refcnt > 0);
 
+	SDT_PROBE(io,,,wait_start, bp, NULL, NULL, NULL, NULL);
+
 	mutex_enter(bp->b_objlock);
 	while (!ISSET(bp->b_oflags, BO_DONE | BO_DELWRI))
 		cv_wait(&bp->b_done, bp->b_objlock);
 	mutex_exit(bp->b_objlock);
 
+	SDT_PROBE(io,,,wait_done, bp, NULL, NULL, NULL, NULL);
+
 	return bp->b_error;
 }
 
@@ -1529,11 +1547,20 @@ biodone(buf_t *bp)
 	}
 }
 
+SDT_PROBE_DEFINE(io,,,done,done,
+    "struct buf *", NULL,	/* arg0: bp */
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL,
+    NULL, NULL);
+
 static void
 biodone2(buf_t *bp)
 {
 	void (*callout)(buf_t *);
 
+	SDT_PROBE(io,,,done, bp, NULL, NULL, NULL, NULL);
+
 	mutex_enter(bp->b_objlock);
 	/* Note that the transfer is done. */
 	if (ISSET(bp->b_oflags, BO_DONE))