Re: [PATCH net] bonding: make debugging output more succinct

[Jarod Wilson <jarod@redhat.com>]

On 5/24/19 11:19 AM, Joe Perches wrote:
> On Fri, 2019-05-24 at 09:56 -0400, Jarod Wilson wrote:
>> Seeing bonding debug log data along the lines of "event: 5" is a bit spartan,
>> and often requires a lookup table if you don't remember what every event is.
>> Make use of netdev_cmd_to_name for an improved debugging experience, so for
>> the prior example, you'll see: "bond_netdev_event received NETDEV_REGISTER"
>> instead (both are prefixed with the device for which the event pertains).
>>
>> There are also quite a few places that the netdev_dbg output could stand to
>> mention exactly which slave the message pertains to (gets messy if you have
>> multiple slaves all spewing at once to know which one they pertain to).
> []
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> []
>> @@ -1515,7 +1515,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
>>   	new_slave->original_mtu = slave_dev->mtu;
>>   	res = dev_set_mtu(slave_dev, bond->dev->mtu);
>>   	if (res) {
>> -		netdev_dbg(bond_dev, "Error %d calling dev_set_mtu\n", res);
>> +		netdev_dbg(bond_dev, "Error %d calling dev_set_mtu for slave %s\n",
>> +			   res, slave_dev->name);
> 
> Perhaps better to add and use helper mechanisms like:
> 
> #define slave_dbg(bond_dev, slave_dev, fmt, ...)				\
> 	netdev_dbg(bond_dev, "(slave %s) " fmt, (slave_dev)->name, ##__VA_ARGS__)
> 
> So this might be
> 		slave_dbg(bond_dev, slave_dev, "Error %d calling dev_set_mtu\n",
> 			  res);
> etc...
> 
> So there would be a unified style to grep in the logs.

I do kind of like that idea. Might also need slave_info and friends as 
well if you really want to get consistent, and eliminate bond_dev as an 
arg to it, since you can figure that out from slave_dev. I'd be game to 
take that little project on. Might be worth peeling out the 
netdev_cmd_to_name() bit from this for consideration right now, since 
it's not quite part of that same conversion.

-- 
Jarod Wilson
jarod@redhat.com