Re: [RFC net-next 07/14] Fix intel/ixgbe

On 6/20/2012 1:55 AM, Eric Dumazet wrote:

On Tue, 2012-06-19 at 08:54 -0700, Alexander Duyck wrote:

quoted

This patch doesn't limit the number of queues.  It is limiting the
number of interrupts.  The two are not directly related as we can
support multiple queues per interrupt.

Also this change assumes we are only using receive side scaling.  We
have other features such as DCB, FCoE, and Flow Director which require
additional queues.

Yet, it would be good if ixgbe doesnt allocate 36 queues on a 4 cpu
machine.

"tc -s class show dev eth0" output is full of not used classes.

We do this for the DCB/FCoE/RSS/Flow Director case where we want to
use multiple queues per traffic class (802.1Qaz). As it is now we
have to set the max queues at alloc_etherdev_mq() time so we use a
max of
	(num_cpu * max traffic classes) + num_cpu

The last num_cpu is in error and I have a patch in JeffK's tree to
remove this. In many cases it seems excessive but sometimes it is
helpful.

.John