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From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH 4/5 v2] ifb: add multiqueue support
Date: Wed, 15 Dec 2010 07:37:44 +0100
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Cc: Jamal Hadi Salim <hadi@cyberus.ca>,
	"David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org
To: Changli Gao <xiaosuo@gmail.com>
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Le mercredi 15 d=C3=A9cembre 2010 =C3=A0 08:20 +0800, Changli Gao a =C3=
=A9crit :
> On Tue, Dec 14, 2010 at 11:59 PM, Eric Dumazet <eric.dumazet@gmail.co=
m> wrote:
> >
> >
> > There is a problem here.
> >
> > You should sum in the loop rx_counters only, (the counters syncp
> > protected), and use dev_txq_stats_fold() to get the tx_counters fro=
m
> > core network.
>=20
> Hmm, in ifb, txq->tx_counters aren't used in ifb_xmit() but
> ri_tasklet(). IOW, rx and tx are reversed. Here I use txq->tx_counter=
s
> to reduce duplicate counters in ifb_q_private. Unless these variables
> might be accessed outside of ifb, I can use them freely? Thanks.
>=20

Yes, you are right, and the txq lock is not necessary to read their
values as well (I thought it was hold at write time)