[dpdk-dev] [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership

[Gaëtan Rivet]

Hi Matan,

On Sat, Jan 20, 2018 at 06:14:13PM +0000, Matan Azrad wrote:

<snip>

> > > > > > > @@ -1394,7 +1394,7 @@ struct cmd_config_speed_all {
> > > > > > >  			&link_speed) < 0)
> > > > > > >  		return;
> > > > > > >
> > > > > > > -	RTE_ETH_FOREACH_DEV(pid) {
> > > > > > > +	RTE_ETH_FOREACH_DEV_OWNED_BY(pid, my_owner.id) {
> > > > > >
> > > > > > Why do we need all these changes?
> > > > > > As I understand you changed definition of RTE_ETH_FOREACH_DEV(),
> > > > > > so no testpmd should work ok default (no_owner case).
> > > > > > Am I missing something here?
> > > > >
> > > > > Now, After Gaetan suggestion RTE_ETH_FOREACH_DEV(pid) will iterate
> > > > over all valid and ownerless ports.

To be clear: you did not implement what I suggested, but your own
interpretation of it. Please do not write as if I validated this
interpretation.

Essentially, the NO_OWNER semantic is completely different from a
default owner. A default owner would protect ports from race conditions
and force port ownership requests to go through proper channels
protected by critical sections.

NO_OWNER means that anyone is free to take any ownerless port at any
time. And as a result, your are thus forced here to fix this by
modifying an existing application for any entity using your ownership
API to function with it.

This is very different from what I suggested. What I said was that I
wanted the most common case to be taken care of, and for existing
applications to continue working. It entails having a more complicated
API, but I think this is a price we should pay.

You are implementing the most common case in testpmd (the app entity
creating an owner and putting its valid ports within). Your API should
ease that up as much as possible before considering forcing everyone to
work with it.

                           ~*~

You implemented a way for the failsafe to capture existing ports.
How does it work without the channels for requesting ports suggested above?

Regards,
-- 
Gaëtan Rivet
6WIND