The receive ring buffers on the X3522 adapter contain descriptors each of which references a packet buffer (see Figure 2). By default there are 2048 descriptor entries per ring. The user can identify and reconfigure the receive ring buffer size using the ethtool command.
Note: Transmit on the X3522 does not use a ring buffer, and so you cannot
configure the transmit ring buffer size.
To identify the current ring buffer size (in packet buffers):
ethtool -g <interface>
This also shows the maximum size that can be set.
To set the new receive ring buffer size to value N:
ethtool -G <interface> [rx N]
where N has a minimum value of 1024, and must be a multiple of 512.