[ixgbe] Register txd/rxd sysctl values

Hi,

This patch adds and hw.ixgbe tree and adds rxd/txd. These are already
tunables but it wasn't easy to see if these were being set.

I'd like to commit this soon.

Thanks!


-adrian

adrian_at_freebsd-10-hack2:~/work/freebsd/head/src/sys/dev/ixgbe % svn diff .
Index: ixgbe.c
===================================================================
--- ixgbe.c     (revision 253553)
+++ ixgbe.c     (working copy)
_at__at_ -234,6 +234,8 _at__at_
 ** TUNEABLE PARAMETERS:
 */

+static SYSCTL_NODE(_hw, OID_AUTO, ixgbe, CTLFLAG_RD, 0, "IXGBE driver
parameters");
+
 /*
 ** AIM: Adaptive Interrupt Moderation
 ** which means that the interrupt rate
_at__at_ -291,6 +293,11 _at__at_
 static int ixgbe_rxd = PERFORM_RXD;
 TUNABLE_INT("hw.ixgbe.rxd", &ixgbe_rxd);

+SYSCTL_INT(_hw_ixgbe, OID_AUTO, rxd, CTLFLAG_RDTUN, &ixgbe_rxd, 0,
+    "Number of receive descriptors per queue");
+SYSCTL_INT(_hw_ixgbe, OID_AUTO, txd, CTLFLAG_RDTUN, &ixgbe_txd, 0,
+    "Number of transmit descriptors per queue");
+
 /*
 ** Defining this on will allow the use
 ** of unsupported SFP+ modules, note that
adrian_at_freebsd-10-hack2:~/work/freebsd/head/src/sys/dev/ixgbe %