Re: [PATCH] vhost: change mbuf allocation logs to debug

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Tue, Mar 28, 2017 at 11:39:37AM +0000, Legacy, Allain wrote:
> > -----Original Message-----
> > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com]
> > Sent: Tuesday, March 28, 2017 2:49 AM
> <...>
> > > In order to prevent this condition, but
> > > still enable debugging, the logs are being changed to debug logs to ensure
> > > they are not emitted unless the CONFIG_RTE_LIBRTE_VHOST_DEBUG
> > option is
> > > enabled.
> > 
> > That basically means you will never see them in real life. I'm suggesting
> > to add a new log API, RTE_LOG_ONCE. Sounds good?
> 
> 
> Rather than a log what is really needed here is a stat/counter, but this library does not have the infrastructure in place to support reporting datapath errors via stats back to the application.

Right. It's supposed to be done in vhost-pmd, while the real Rx implementation
is at vhost lib.

>  Are there any plans to add a stats infrastructure or a desired design for what that would look like?

We could have such counter support once we move virtio_net.c to vhost-pmd.
Unluckily, I don't think it will happen soon.

OTOH, it's still good to have RTE_LOG_ONCE. It explicitly tells you something
is wrong, then you could dump those stats for more info.

	--yliu