Disable copybreak

[people/ms/network.git] / src / modprobe.d / no-copybreak.conf

#
# 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 bcm63xx 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 pch_gbe copybreak=0
options pcnet32 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