sk98lin is the Gigabit Ethernet driver for Marvell and SysKonnect network adapter cards. It supports SysKonnect SK-98xx/SK-95xx compliant Gigabit Ethernet Adapter and any Yukon compliant chipset.
When loading the driver using insmod, parameters for the network adapter cards might be stated as a sequence of comma separated commands. If for instance two network adapters are installed and AutoNegotiation on Port A of the first adapter should be ON, but on the Port A of the second adapter switched OFF, one must enter:
insmod sk98lin.o AutoNeg_A=On,Off
After sk98lin is bound to one or more adapter cards and the /proc filesystem is mounted on your system, a dedicated statistics file will be created in the folder /proc/net/sk98lin for all ports of the installed network adapter cards. Those files are named eth[x], where x is the number of the interface that has been assigned to a dedicated port by the system.
If loading is finished, any desired IP address can be assigned to the respective eth[x] interface using the ifconfig(8) command. This causes the adapter to connect to the Ethernet and to display a status message on the console saying "ethx: network connection up using port y" followed by the configured or detected connection parameters.
The sk98lin also supports large frames (also called jumbo frames). Using jumbo frames can improve throughput tremendously when transferring large amounts of data. To enable large frames, the MTU (maximum transfer unit) size for an interface is to be set to a high value. The default MTU size is 1500 and can be changed up to 9000 (bytes). Setting the MTU size can be done when assigning the IP address to the interface or later by using the ifconfig(8) command with the mtu parameter. If for instance eth0 needs an IP address and a large frame MTU size, the following two commands might be used:
ifconfig eth0 10.1.1.1
ifconfig eth0 mtu 9000
Those two commands might even be combined into one:
ifconfig eth0 10.1.1.1 mtu 9000
Note that large frames can be used only if permitted by your network infrastructure. This means, that any switch being used in your Ethernet must also support large frames. Quite some switches support large frames, but need to be configured to do so. Most of the times, their default setting is to support only standard frames with an MTU size of 1500 (bytes). In addition to the switches inside the network, all network adapters that are to be used must also be enabled regarding jumbo frames. If an adapter is not set to receive large frames, it will simply drop them.
Switching back to the standard Ethernet frame size can be done by using the ifconfig(8) command again:
ifconfig eth0 mtu 1500
The Marvell/SysKonnect Gigabit Ethernet driver for Linux is able to support VLAN and Link Aggregation according to IEEE standards 802.1, 802.1q, and 802.3ad. Those features are available only after installation of open source modules which can be found on the Internet:
VLAN:
Link
Aggregation:
Note that Marvell/SysKonnect does not offer any support for these
open source modules and does not take the responsibility for any
kind of failures or problems arising when using these modules.
Sym
= Symmetric
both link partners are allowed to send PAUSE frames
SymOrRem
= SymmetricOrRemote
both or only remote partner are allowed to send PAUSE frames
LocSend
= LocalSend
only local link partner is allowed to send PAUSE frames
None
= None
no link partner is allowed to send PAUSE frames
Note that this parameter is ignored if AutoNeg_A is set to Off.
Sym
= Symmetric
both link partners are allowed to send PAUSE frames
SymOrRem
= SymmetricOrRemote
both or only remote partner are allowed to send PAUSE frames
LocSend
= LocalSend
only local link partner is allowed to send PAUSE frames
None
= None
no link partner is allowed to send PAUSE frames
Note that this parameter is ignored if AutoNeg_B is set to Off.
ConType | DupCap AutoNeg FlowCtrl Role Speed --------+------------------------------------------- Auto | Both On SymOrRem Auto AutoStating any other port parameter together with this ConType parameter will result in a merged configuration of those settings. This is due to the fact, that the per-port parameters (e.g., Speed_A) have a higher priority than the combined variable ConType.
100FD | Full Off None Auto 100
100HD | Half Off None Auto 100
10FD | Full Off None Auto 10
10HD | Half Off None Auto 10
None No interrupt moderation is applied on the adapter card. Therefore, each transmit or receive interrupt is served immediately as soon as it appears on the interrupt line of the adapter card.
Static
Interrupt moderation is applied on the adapter card.
All transmit and receive interrupts are queued until
a complete moderation interval ends.
If such a moderation interval ends, all queued interrupts
are processed in one big bunch without any delay.
The term
Static
reflects the fact, that interrupt moderation is always enabled,
regardless how much network load is currently passing via a
particular interface.
In addition, the duration of the moderation interval has a fixed
length that never changes while the driver is operational.
Dynamic
Interrupt moderation might be applied on the adapter card,
depending on the load of the system.
If the driver detects that the system load is too high,
the driver tries to shield the system against too much network
load by enabling interrupt moderation.
If---at a later time---the CPU utilization decreases
again (or if the network load is negligible), the interrupt
moderation will automatically be disabled.
Interrupt moderation should be used when the driver has to handle one or more interfaces with a high network load, which---as a consequence---leads also to a high CPU utilization. When moderation is applied in such high network load situations, CPU load might be reduced by 20-30% on slow computers.
Note that the drawback of using interrupt moderation is an increase of the round-trip-time (RTT), due to the queuing and serving of interrupts at dedicated moderation times.
This parameter is used only if either static or dynamic interrupt moderation is enabled on a network adapter card. This parameter is ignored if no moderation is applied.
Note that the duration of the moderation interval is to be chosen with care. At first glance, selecting a very long duration (e.g., only 100 interrupts per second) seems to be meaningful, but the increase of packet-processing delay is tremendous. On the other hand, selecting a very short moderation time might compensate the use of any moderation being applied.
CheckLinkState Check link state only: RLMT uses the link state reported by the adapter hardware for each individual port to determine whether a port can be used for all network traffic or not.
CheckLocalPort
In this mode, RLMT monitors the network path between the two
ports of an adapter by regularly exchanging packets between them.
This mode requires a network configuration in which the
two ports are able to "see" each other (i.e., there
must not be any router between the ports).
CheckSeg
Check local port and segmentation:
This mode supports the same functions as the CheckLocalPort
mode and additionally checks network segmentation between the ports.
Therefore, this mode is to be used only if Gigabit Ethernet
switches are installed on the network that have been
configured to use the Spanning Tree protocol.
DualNet
In this mode, ports A and B are used as separate devices.
If you have a dual port adapter, port A will be configured as
eth[x]
and port B as
eth[x+1].
Both ports can be used independently with distinct IP addresses.
The preferred port setting is not used.
RLMT is turned off.
Note that RLMT modes CheckLocalPort and CheckLinkState are designed to operate in configurations where a network path between the ports on one adapter exists. Moreover, they are not designed to work where adapters are connected back-to-back.