Too much interrupts on ixgbe

[Arnaud Lacombe]

Hi,

On Mon, Oct 24, 2011 at 4:32 PM, Ryan Stone <rysto32 at gmail.com> wrote:
> On Mon, Oct 24, 2011 at 3:51 PM, Sergey Saley <sergeysaley at gmail.com> wrote:
>> MPD5, netgraph, pppoe.Types of traffic - any (customer traffic).
>> Bying this card I counted on a 3-4G traffic at 3-4K pppoe sessions.
>> It turned to 600-700Mbit/s, about 50K pps at 700-800 pppoe sessions.
>
> PPPoE is your problem.  The Intel cards can't load-balance PPPoE
> traffic, so everything goes to one queue.  It may be possible to write
> a netgraph module to load-balance the traffic across your CPUs.
>
NetGraph already runs a thread per CPU, as you can see in top's
output. There is also still have plenty of CPU usable, so I'd assume
some hard-limit are hit, maybe any of `net.graph.maxdata' or
`net.graph.maxalloc'.

Sergey, what is the output of:

# vmstat -z | grep NetGraph

Thanks,
 - Arnaud