# Re: \[PATCH net-next v12 1/5\] net: Introduce generic failover module

- From: Samudrala, Sridhar \<sridhar.samudrala@intel.com\>
- Date: 2018-05-25 23:04:33 
- List: netdev
- Page: https://ratatoskr.run/netdev/2018/05/11097382
- Thread: https://ratatoskr.run/netdev/2018/05/11097172/t.md

```text


On 5/25/2018 3:37 PM, Stephen Hemminger wrote:
> On Thu, 24 May 2018 09:55:13 -0700
> Sridhar Samudrala [ref] wrote:
>
>
>> +	spin_lock(&failover_lock);
> Since register is not in fast path, this should be a mutex?

This is Jiri's comment which made me to switch to spinlock from mutex

  >> Why mutex? Apparently you don't need to sleep while holding a lock.
  >> Simple spinlock would do.

>
>
>> +int failover_slave_unregister(struct net_device *slave_dev)
>> +{
>> +	struct net_device *failover_dev;
>> +	struct failover_ops *fops;
>> +
>> +	if (!netif_is_failover_slave(slave_dev))
>> +		goto done;
>> +
>> +	ASSERT_RTNL();
>> +
>> +	failover_dev = failover_get_bymac(slave_dev->perm_addr, &fops);
>> +	if (!failover_dev)
>> +		goto done;
> Since the slave device must have a master device set already, why not use
> that instead of searching by MAC address on unregister or link change.
>
We also need to get the fops(failover_ops)

```