Re: [RFC] net: napi fix

Joonwoo Park
2007-12-13T07:41:35Z

2007/12/13, Kok, Auke <auke-jan.h.kok@intel.com>:
> David Miller wrote:
> > From: Andrew Gallatin <gallatin@myri.com>
> > Date: Wed, 12 Dec 2007 12:29:23 -0500
> >
> >> Is the netif_running() check even required?
> >
> > No, it is not.
> >
> > When a device is brought down, one of the first things
> > that happens is that we wait for all pending NAPI polls
> > to complete, then block any new polls from starting.
>
> I think this was previously (pre-2.6.24) not the case, which is why e1000 et al
> has this check as well and that's exactly what is causing most of the
> net_rx_action oopses in the first place. Without the netif_running() check
> previously the drivers were just unusable with NAPI and prone to many races with
> down (i.e. touching some ethtool ioctl which wants to do a reset while routing
> small packets at high numbers). that's why we added the netif_running() check in
> the first place :)
>
> There might be more drivers lurking that need this change...
>
> Auke
>

Also in my case, without netif_running() check, I cannot do ifconfig down.
It stucked if packet generator was sending packets.

Thanks
Joonwoo