Subject: Re: [PATCH net-next v12 2/4] ethtool: provide customized dim profile management

From: Jakub Kicinski <[email-masked]>
Date: Wed, 8 May 2024 08:11:39 -0700

On Wed, 8 May 2024 21:26:46 +0800 Heng Qi wrote:
> On Tue, 7 May 2024 19:57:52 -0700, Jakub Kicinski <[email-masked]> wrote:
> > On Sat,  4 May 2024 14:44:45 +0800 Heng Qi wrote:  
> > > @@ -1325,6 +1354,8 @@ operations:
> > >              - tx-aggr-max-bytes
> > >              - tx-aggr-max-frames
> > >              - tx-aggr-time-usecs
> > > +            - rx-profile
> > > +            - tx-profil
> > >        dump: *coalesce-get-op
> > >      -
> > >        name: coalesce-set  
> > 
> > set probably needs to get the new attributes, too?  
> 
> I looked at other similar use cases (such as wol, debug) and it doesn't
> seem to be needed?

Sorry, you're right, they are propagated using a YAML alias.

> > > +static int ethnl_update_profile(struct net_device *dev,
> > > +				struct dim_cq_moder __rcu **dst,
> > > +				const struct nlattr *nests,
> > > +				struct netlink_ext_ack *extack)  
> >   
> > > +	rcu_assign_pointer(*dst, new_profile);
> > > +	kfree_rcu(old_profile, rcu);
> > > +
> > > +	return 0;  
> > 
> > Don't we need to inform DIM somehow that profile has switched
> > and it should restart itself?  
> 
> When the profile is modified, dim itself is a dynamic adjustment mechanism
> and will quickly adjust to the appropriate value according to the new profile.
> This is also seen in practice.

Okay, perhaps add a comment to that effect?