# # **** License **** # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License version 2 as # published by the Free Software Foundation. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # This code was originally developed by Vyatta, Inc. # Portions created by Vyatta are Copyright (C) 2009 Vyatta, Inc. # All Rights Reserved. # **** End License **** # # Author: Bob Gilligan # # Some network interface drivers employ a scheme known as "copybreak" # in which they make a copy of a received skb if the size of the # buffer is below a particular threshold, then return the original # receive skb back to the pool. Since these drivers initially # allocate a buffer size that is larger than the largest possible # packet, this scheme returns that large buffer to the pool quickly, # and uses a smaller one. # # The primary benefit of copybreak is better memory utilization. On # systems where the data is ultimately going to be copied out to user # space, the copybreak scheme is "low cost" because it has the side # benefit of priming the cache for that later copy. But on a router # that only touches the header fields of a received packet, the cost # can be relatively higher. And on modern systems the memory savings # is rarely an important consideration. # # Some of the drivers that employ copybreak make the feature # configurable via a module parameter. This file disables copybreak # in some of those drivers. Generally this results in an improvement # in forwarding performance for traffic using these drivers. # options 3c515 rx_copybreak=0 options 3c59x rx_copybreak=0 options cxgb copybreak=0 options e1000 copybreak=0 options e1000e copybreak=0 options epic100 rx_copybreak=0 options fealnx rx_copybreak=0 options hamachi rx_copybreak=0 options ixgb copybreak=0 options natsemi rx_copybreak=0 options pcnet32 rx_copybreak=0 options r8169 rx_copybreak=0 options sis190 rx_copybreak=0 options sky2 copybreak=0 options starfire rx_copybreak=0 options sundance rx_copybreak=0 options typhoon rx_copybreak=0 options via-rhine rx_copybreak=0 options via-velocity rx_copybreak=0 options yellowfin rx_copybreak=0