Re: [PATCH net] iavf: Do not restart Tx queues after reset task failure

[Ivan Vecera]

On Wed, 9 Nov 2022 20:11:55 +0000
"Keller, Jacob E" <jacob.e.keller@xxxxxxxxx> wrote:

> > Sorry for my naive question, I see this pattern a lot (including RDMA),
> > so curious. Everyone checks netif_running() outside of rtnl_lock, while
> > dev_close() changes state bit __LINK_STATE_START. Shouldn't rtnl_lock()
> > placed before netif_running()?  
> 
> Yes I think you're right. A ton of people check it without the lock but I think thats not strictly safe. Is dev_close safe to call when netif_running is false? Why not just remove the check and always call dev_close then.
> 
> Thanks,
> Jake

Check for a bit value (like netif_runnning()) is much cheaper than unconditionally
taking global lock like RTNL.

Ivan