ixgbe: Set Drop_EN bit when multiple Rx queues are present w/o flow control
authorAlexander Duyck <alexander.h.duyck@intel.com>
Wed, 25 Apr 2012 04:36:38 +0000 (04:36 +0000)
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>
Thu, 10 May 2012 05:31:44 +0000 (22:31 -0700)
commit3ebe8fdeb043e8c630cac6dc90d483e729e17017
treed4f16a8ac2bb88460cf817477d5acb4a3e18f54d
parent943561d3e7f82645aafb65839feb9f99e2718bac
ixgbe: Set Drop_EN bit when multiple Rx queues are present w/o flow control

The drop enable bit can be used to improve the performance of the adapter
in the case of multiple queues being present.  This performance gain is due
to the fact that some slower CPUs can cause the FIFO to backfill preventing
faster CPUs from receiving additional work.  By setting the drop enable bit
we prevent this and instead just drop the packets that would have been
bound for the slower CPU.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
drivers/net/ethernet/intel/ixgbe/ixgbe.h
drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_nl.c
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c