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, 7 insertions, 0 deletions

diff --git a/sys/dev/usb2/controller/usb2_bus.h b/sys/dev/usb2/controller/usb2_bus.h
index 43776fd..c81a7a5 100644
--- a/sys/dev/usb2/controller/usb2_bus.h
+++ b/sys/dev/usb2/controller/usb2_bus.h
@@ -53,6 +53,13 @@ struct usb2_bus {
 	struct usb2_bus_stat stats_ok;
 	struct usb2_process explore_proc;
 	struct usb2_process roothub_proc;
+	/*
+	 * There are two callback processes. One for Giant locked
+	 * callbacks. One for non-Giant locked callbacks. This should
+	 * avoid congestion and reduce response time in most cases.
+	 */
+	struct usb2_process giant_callback_proc;
+	struct usb2_process non_giant_callback_proc;
 	struct usb2_bus_msg explore_msg[2];
 	struct usb2_bus_msg detach_msg[2];
 	struct usb2_bus_msg attach_msg[2];