Re: ixgbe question

[Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>]

On Tue, 2009-11-24 at 02:55 -0700, Eric Dumazet wrote:
> Peter P Waskiewicz Jr a écrit :
> 
> > You might have this elsewhere, but it sounds like you're connecting back
> > to back with another 82599 NIC.  Our optics in that NIC are dual-rate,
> > and the software mechanism that tries to "autoneg" link speed gets out
> > of sync easily in back-to-back setups.
> > 
> > If it's really annoying, and you're willing to run with a local patch to
> > disable the autotry mechanism, try this:
> > 
> > diff --git a/drivers/net/ixgbe/ixgbe_main.c
> > b/drivers/net/ixgbe/ixgbe_main.c
> > index a5036f7..62c0915 100644
> > --- a/drivers/net/ixgbe/ixgbe_main.c
> > +++ b/drivers/net/ixgbe/ixgbe_main.c
> > @@ -4670,6 +4670,10 @@ static void ixgbe_multispeed_fiber_task(struct
> > work_struct *work)
> >         autoneg = hw->phy.autoneg_advertised;
> >         if ((!autoneg) && (hw->mac.ops.get_link_capabilities))
> >                 hw->mac.ops.get_link_capabilities(hw, &autoneg,
> > &negotiation);
> > +
> > +       /* force 10G only */
> > +       autoneg = IXGBE_LINK_SPEED_10GB_FULL;
> > +
> >         if (hw->mac.ops.setup_link)
> >                 hw->mac.ops.setup_link(hw, autoneg, negotiation, true);
> >         adapter->flags |= IXGBE_FLAG_NEED_LINK_UPDATE;
> 
> Thanks ! This did the trick :)
> 
> If I am not mistaken, number of TX queues should be capped by number of possible cpus ?
> 
> Its currently a fixed 128 value, allocating 128*128 = 16384 bytes,
> and polluting "tc -s -d class show dev fiber0" output.
> 

Yes, this is a stupid issue we haven't gotten around to fixing yet.
This looks fine to me.  Thanks for putting it together.

> [PATCH net-next-2.6] ixgbe: Do not allocate too many netdev txqueues
> 
> Instead of allocating 128 struct netdev_queue per device, use the minimum
> value between 128 and number of possible cpus, to reduce ram usage and
> "tc -s -d class show dev ..." output
> 
> diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
> index ebcec30..ec2508d 100644
> --- a/drivers/net/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ixgbe/ixgbe_main.c
> @@ -5582,7 +5583,10 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
>  	pci_set_master(pdev);
>  	pci_save_state(pdev);
>  
> -	netdev = alloc_etherdev_mq(sizeof(struct ixgbe_adapter), MAX_TX_QUEUES);
> +	netdev = alloc_etherdev_mq(sizeof(struct ixgbe_adapter),
> +				   min_t(unsigned int,
> +					 MAX_TX_QUEUES,
> +					 num_possible_cpus()));
>  	if (!netdev) {
>  		err = -ENOMEM;
>  		goto err_alloc_etherdev;