MFp4: //depot/projects/usb@155842

	Reduce the number of callback processes to 4 per
	USB controller. There are two rough categories:
	1) Giant locked USB transfers.
	2) Non-Giant locked USB transfers.
	On a real system with many USB devices plugged in the
	number of processes reported by "ps auxw | grep USBPROC"
	was reduced from 40 to 18.

Submitted by: Hans Petter Selasky

1 files changed, 16 insertions, 2 deletions

diff --git a/sys/dev/usb2/controller/usb2_controller.c b/sys/dev/usb2/controller/usb2_controller.c
index 61ce314..a9596c7 100644
--- a/sys/dev/usb2/controller/usb2_controller.c
+++ b/sys/dev/usb2/controller/usb2_controller.c
@@ -166,6 +166,11 @@ usb2_detach(device_t dev)
 
 	USB_BUS_UNLOCK(bus);
 
+	/* Get rid of USB callback processes */
+
+	usb2_proc_unsetup(&bus->giant_callback_proc);
+	usb2_proc_unsetup(&bus->non_giant_callback_proc);
+
 	/* Get rid of USB roothub process */
 
 	usb2_proc_unsetup(&bus->roothub_proc);
@@ -391,8 +396,17 @@ usb2_attach_sub(device_t dev, struct usb2_bus *bus)
 	bus->roothub_msg[1].hdr.pm_callback = &usb2_bus_roothub;
 	bus->roothub_msg[1].bus = bus;
 
-	/* Create USB explore and roothub processes */
-	if (usb2_proc_setup(&bus->roothub_proc,
+	/* Create USB explore, roothub and callback processes */
+
+	if (usb2_proc_setup(&bus->giant_callback_proc,
+	    &bus->bus_mtx, USB_PRI_MED)) {
+		printf("WARNING: Creation of USB Giant "
+		    "callback process failed.\n");
+	} else if (usb2_proc_setup(&bus->non_giant_callback_proc,
+	    &bus->bus_mtx, USB_PRI_HIGH)) {
+		printf("WARNING: Creation of USB non-Giant "
+		    "callback process failed.\n");
+	} else if (usb2_proc_setup(&bus->roothub_proc,
 	    &bus->bus_mtx, USB_PRI_HIGH)) {
 		printf("WARNING: Creation of USB roothub "
 		    "process failed.\n");