netdev - Re: ixgbe warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <OF78047910.1202C26A-ON65257695.0030A7D8-65257695.00313863@in.ibm.com>
Date:	Wed, 23 Dec 2009 14:38:55 +0530
From:	Krishna Kumar2 <krkumar2@...ibm.com>
To:	Yinghai Lu <yinghai@...nel.org>
Cc:	David Miller <davem@...emloft.net>,
	e1000-devel@...ts.sourceforge.net, NetDev <netdev@...r.kernel.org>
Subject: Re: ixgbe warning

> Krishna Kumar2/India/IBM@...IN wrote
>
> > > I guess you are running on a big SMP system? If so,
> > > ixgbe_select_queue() is not limiting the queue_index
> > > based on real_num_tx_queues, and possibly returning
> > > a bad txq from:
> > >
> > >       if (adapter->flags & IXGBE_FLAG_FDIR_HASH_CAPABLE)
> > >             return txq;
> > >
> > > Also, I was looking at other providers of select_queue and found:
> > >
> > > u16 gfar_select_queue(struct net_device *dev, struct sk_buff *skb)
> > > {
> > >         return skb_get_queue_mapping(skb);
> > > }
> > >
> > > How can this be correct (driver supports upto 8 txq's). Unless txq=0
> for
> > > xmits of all locally
> > > generated packets is fine.
> >
> > may need this one...
> >
> > ---
> >  drivers/net/ixgbe/ixgbe_main.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: linux-2.6/drivers/net/ixgbe/ixgbe_main.c
> > ===================================================================
> > --- linux-2.6.orig/drivers/net/ixgbe/ixgbe_main.c
> > +++ linux-2.6/drivers/net/ixgbe/ixgbe_main.c
> > @@ -5317,7 +5317,7 @@ static int ixgbe_maybe_stop_tx(struct ne
> >  static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff
> *skb)
> >  {
> >     struct ixgbe_adapter *adapter = netdev_priv(dev);
> > -   int txq = smp_processor_id();
> > +   int txq = smp_processor_id() % adapter->num_tx_queues;
> >
> >     if (adapter->flags & IXGBE_FLAG_FDIR_HASH_CAPABLE)
> >        return txq;
>
> The modulo operation is not required (and costly too) for
> other cases. You should move it inside the if case, or I
> guess Jeff can suggest the right fix.

BTW, do your warnings disappear when you put the modulo inside
the above 'if' condition?

thanks,

- KK

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html