Re: [RFT] netif_queue_stopped in TBF scheduler

["David S. Miller" <davem@xxxxxxxxxx>]

On Thu, 17 Jun 2004 16:09:30 -0700
Stephen Hemminger <shemminger@xxxxxxxx> wrote:

> There is a race between the device and scheduler if the scheduler looks
> at netif_queue_stopped.  What can happen is that the device decides it is 
> ready,
> just after the stopped check, and the scheduler decides it is throttled.
> 
> The simple way is to just have the scheduler always dequeue and leave the flow
> control up to the driver and the core scheduling loop.

CBQ, HFSC, etc. etc. have this same logic too.

I agree, the flow control should be handled at the top level by
qdisc_restart(), and it does by invoking ->requeue() if the xmit
fails at the device level or it cannot obtain the necessary locks.

I'm going to make this fix across the board.