Re: [RFC v2 1/1] net: Add support to configure SR-IOV VF minimum and maximum Tx rate through ip tool.

Ben Hutchings
2014-03-28T00:26:28Z

[-- Attachment #1: Type: text/plain, Size: 1146 bytes --]

On Wed, 2014-03-26 at 08:37 +0100, Michal Kubecek wrote:
> On Monday 24 of March 2014 18:55:00 Ben Hutchings wrote:
> >
> > Also, this special-casing of -1 isn't documented anywhere. Is it even
> > necessary? If userland needs to set just one limit, it can read the
> > existing limits and set both.
>
> Wouldn't this open a window for a race if one process wanted to change
> one limit and another process wanted to change the other at the same
> time? Such scenario doesn't sound very realistic but our customers
> taught me that things I don't find very realistic tend to be used quite
> frequently by them.

If there are two processes trying to change the minimum and maximum
bandwidth of a VF at the same time, something has gone wrong already.
This is a problem for userland to solve.

Ben.

> On the other hand, if changing only one limit is going to be common, it
> might be more appropriate to add IFLA_VF_TX_MIN_RATE instead and always
> pass the minimum and maximum rate separately (and pass only one if only
> one is going to be changed).

--
Ben Hutchings
73.46% of all statistics are made up.

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 811 bytes --]