Subject: Re: [PATCH] netdev: hotplug napi race cleanup

From: Stephen Hemminger <[email-masked]>
Date: Mon, 8 May 2006 09:54:58 -0700

On Sat, 06 May 2006 18:09:47 -0700 (PDT)
"David S. Miller" <[email-masked]> wrote:

> From: Stephen Hemminger <[email-masked]>
> Date: Mon, 24 Apr 2006 15:23:41 -0700
> 
> > This follows after the earlier two patches.
> > 
> > Change the initialization of the class device portion of the net device
> > to be done earlier, so that any races before registration completes are
> > harmless.  Add a mutex to avoid changes to netdevice during the
> > class device registration. 
> > 
> > Signed-off-by: Stephen Hemminger <[email-masked]>
> 
> I'm not going to apply this patch and instead request that we think
> about why this problem exists in the first place.
> 
> This patch is even stronger evidence that doing the sysfs registry in
> the todo list processing is wrong.  If you can legally do this while
> holding the rtnl semaphore, you can just as equally do it inside of
> register_netdevice() which is where it truly belongs.
> 
> Then you can handle errors properly, unwind the state, and return the
> error to the caller instead of just losing the error and leaving the
> device in a half-registered state.

The issue is are there network devices that can't sleep during
register_netdevice?