From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jarek Poplawski <jarkao2@gmail.com>
Subject: Re: net_sched 07/07: add classful multiqueue dummy scheduler
Date: Wed, 9 Sep 2009 21:52:38 +0200
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Cc: Eric Dumazet <eric.dumazet@gmail.com>, netdev@vger.kernel.org
To: Patrick McHardy <kaber@trash.net>
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On Wed, Sep 09, 2009 at 06:02:59PM +0200, Patrick McHardy wrote:
> Eric Dumazet wrote:
> > Jarek Poplawski a =E9crit :
> >> On Mon, Sep 07, 2009 at 03:27:37PM +0200, Patrick McHardy wrote:
> >>> Jarek Poplawski wrote:
> >> ...
> >>>>> +static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
> >>>>> +{
> >>>>> +	struct net_device *dev =3D qdisc_dev(sch);
> >>>>> +	struct Qdisc *qdisc;
> >>>>> +	unsigned int ntx;
> >>>>> +
> >>>>> +	sch->q.qlen =3D 0;
> >>>>> +	memset(&sch->bstats, 0, sizeof(sch->bstats));
> >>>>> +	memset(&sch->qstats, 0, sizeof(sch->qstats));
> >>>>> +
> >>>>> +	for (ntx =3D 0; ntx < dev->num_tx_queues; ntx++) {
> >>>>> +		qdisc =3D netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
> >>>>> +		spin_lock_bh(qdisc_lock(qdisc));
> >>>>> +		sch->q.qlen		+=3D qdisc->q.qlen;
> >>>>> +		sch->bstats.bytes	+=3D qdisc->bstats.bytes;
> >>>>> +		sch->bstats.packets	+=3D qdisc->bstats.packets;
> >>>>> +		sch->qstats.qlen	+=3D qdisc->qstats.qlen;
> >>>> Like in Christoph's case, we should probably use q.qlen instead.
> >>> Its done a few lines above. This simply sums up all members of qs=
tats.
> >> AFAICS these members are updated only in tc_fill_qdisc, starting f=
rom
> >> the root, so they might be not up-to-date at the moment, unless I =
miss
> >> something.
> >
> > Yes, we might need an q->ops->update_stats(struct Qdisc *sch) metho=
d, and
> > to recursively call it from mq_update_stats()
>=20
> Unless I'm missing something, that shouldn't be necessary since
> sch->q.qlen contains the correct sum of all child qdiscs and
> this is used by tc_fill_qdisc to update qstats.qlen.

You're perfectly right! (And the code is perfectly misleading.;-)

Thanks,
Jarek P.