Subject: Re: [PATCH RFC net-next 7/7] netdevsim: Add simple FIB resource controller via devlink

From: Jiri Pirko <[email-masked]>
Date: Fri, 23 Mar 2018 16:05:16 +0100

Fri, Mar 23, 2018 at 04:03:40PM CET, [email-masked] wrote:
>On 3/23/18 9:01 AM, Jiri Pirko wrote:
>> Fri, Mar 23, 2018 at 03:31:02PM CET, [email-masked] wrote:
>>> On 3/23/18 12:50 AM, Jiri Pirko wrote:
>>>>> +void nsim_devlink_setup(struct netdevsim *ns)
>>>>> +{
>>>>> +	struct net *net = dev_net(ns->netdev);
>>>>> +	bool *reg_devlink = net_generic(net, nsim_devlink_id);
>>>>> +	struct devlink *devlink;
>>>>> +	int err = -ENOMEM;
>>>>> +
>>>>> +	/* only one device per namespace controls devlink */
>>>>> +	if (!*reg_devlink) {
>>>>> +		ns->devlink = NULL;
>>>>> +		return;
>>>>> +	}
>>>>> +
>>>>> +	devlink = devlink_alloc(&nsim_devlink_ops, 0);
>>>>> +	if (!devlink)
>>>>> +		return;
>>>>> +
>>>>> +	devlink_net_set(devlink, net);
>>>>> +	err = devlink_register(devlink, &ns->dev);
>>>>
>>>> This reg_devlink construct looks odd. Why don't you leave the devlink
>>>> instance in init_ns?
>>>
>>> It is a per-network namespace resource controller. Since struct devlink
>> 
>> Wait a second. What do you mean by "per-network namespace"? Devlink
>> instance is always associated with one physical device. Like an ASIC.
>> 
>> 
>>> has a net entry, the simplest design is to put it into the namespace of
>>> the controller. Without it, controlling resource sizes in namespace
>>> 'foobar' has to be done from init_net, which is just wrong.
>
>you need to look at how netdevsim creates a device per netdevice.

That means one devlink instance for each netdevsim device, doesn't it?