Vincenzo Maffione v.maffione at
Thu Feb 16 20:14:21 UTC 2017

  You're right, we'll try to add more details.

In any case, buf_size, ring_size and if_size are the sizes in bytes of each
buffer, ring and netmap_if (control data structure), respectively.
So the maximum amount of slots for each ring is ring_size/16, as 16 is the
size in bytes of struct netmap_slot.

On the other side, buf_num, ring_num and if_num are the total number of
biffers, rings and netmap_if objects in each netmap memory area (aka
By default there is a single memory area used by all the hardware NICs and
a separate memory area for each VALE port.
This is already configurable, however.


2017-02-14 13:36 GMT+01:00 Slawa Olhovchenkov <slw at>:

> On Tue, Feb 14, 2017 at 12:26:55PM +0100, Vincenzo Maffione wrote:
> > Hi,
> >   Have you tried to play with netmap sysctl parameters like:
> >
> > dev.netmap.buf_num
> > dev.netmap.ring_num
> > dev.netmap.if_num
> >
> > those are listed in the sysctl section of the netmap man page.
> man page hide details about calcul rules of this parameters.

Vincenzo Maffione

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