Re: [Bonding-devel] Re: Bonding driver unreliable under high CPUload

[Jeff Garzik <jgarzik@xxxxxxxxxxxxxxxx>]

Chad N. Tindel wrote:
> > > Will netif_carrier_ok(slave_dev) always work?  Do all drivers support the
> > > __LINK_STATE_NOCARRIER flag?
> >
> > No.  Read again the precise language I used :)
>
> Right, well thats what I thought.  But how can we do what Andrew wants?

You'll need execute those ioctls from process context -- or call 
dev->do_ioctl() yourself with proper locking.  The latter would 
certainly be faster but you must be _very_ careful to avoid deadlocks. 
The former would certainly be preferred anyway, because calling an ioctl 
to check link state means you are hitting the slave_dev's phy, which is 
a very expensive operation in and of itself.
Unfortunately I am thinking that locking in bonding.c may need a 
re-think if you want to do this sort of stuff :(  Semaphores instead of 
a spinlocks may be appropriate, depending on the contexts in which 
link_state _really_ needs to be checked.
        Jeff