From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: netdev@vger.kernel.org, Eric Dumazet <eric.dumazet@gmail.com>,
Alexei Starovoitov <ast@plumgrid.com>,
brouer@redhat.com
Subject: Re: [PATCH 2/2] pktgen: introduce xmit_mode 'rx_inject'
Date: Wed, 6 May 2015 10:44:42 +0200 [thread overview]
Message-ID: <20150506104442.009312cf@redhat.com> (raw)
In-Reply-To: <5549A772.9060009@gmail.com>
On Tue, 05 May 2015 22:32:34 -0700
Alexander Duyck <alexander.duyck@gmail.com> wrote:
> On 05/05/2015 01:30 PM, Jesper Dangaard Brouer wrote:
>
> <snip>
>
> > diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> > index 43bb215..85195b2 100644
> > --- a/net/core/pktgen.c
> > +++ b/net/core/pktgen.c
> > @@ -210,6 +210,10 @@
>
> <snip>
>
> > @@ -3320,6 +3358,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > unsigned int burst = ACCESS_ONCE(pkt_dev->burst);
> > struct net_device *odev = pkt_dev->odev;
> > struct netdev_queue *txq;
> > + struct sk_buff *skb;
> > int ret;
> >
> > /* If device is offline, then don't send */
> > @@ -3352,11 +3391,45 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > pkt_dev->last_pkt_size = pkt_dev->skb->len;
> > pkt_dev->allocated_skbs++;
> > pkt_dev->clone_count = 0; /* reset counter */
> > + if (pkt_dev->xmit_mode == M_RX_INJECT)
> > + pkt_dev->skb->protocol = eth_type_trans(pkt_dev->skb,
> > + pkt_dev->skb->dev);
> > }
> >
>
> I was just wondering. Since M_RX_INJECT is not compatible with
> clone_skb couldn't the lines added above be moved down into the block
> below so that you could avoid the additional conditional jump?
Sure, that is possible. I'll let Alexei answer, as it is his code.
(And repost if he also thinks so...)
> > if (pkt_dev->delay && pkt_dev->last_ok)
> > spin(pkt_dev, pkt_dev->next_tx);
> >
> > + if (pkt_dev->xmit_mode == M_RX_INJECT) {
> > + skb = pkt_dev->skb;
> > + atomic_add(burst, &skb->users);
> > + local_bh_disable();
> > + do {
> > + ret = netif_receive_skb(skb);
> > + if (ret == NET_RX_DROP)
> > + pkt_dev->errors++;
> > + pkt_dev->sofar++;
> > + pkt_dev->seq_num++;
> > + if (atomic_read(&skb->users) != burst) {
> > + /* skb was queued by rps/rfs or taps,
> > + * so cannot reuse this skb
> > + */
> > + atomic_sub(burst - 1, &skb->users);
> > + /* get out of the loop and wait
> > + * until skb is consumed
> > + */
> > + pkt_dev->last_ok = 1;
> > + break;
> > + }
> > + /* skb was 'freed' by stack, so clean few
> > + * bits and reuse it
> > + */
> > +#ifdef CONFIG_NET_CLS_ACT
> > + skb->tc_verd = 0; /* reset reclass/redir ttl */
> > +#endif
> > + } while (--burst > 0);
> > + goto out; /* Skips xmit_mode M_TX */
> > + }
> > +
> > txq = skb_get_tx_queue(odev, pkt_dev->skb);
> >
> > local_bh_disable();
> > @@ -3404,6 +3477,7 @@ xmit_more:
> > unlock:
> > HARD_TX_UNLOCK(odev, txq);
> >
> > +out:
> > local_bh_enable();
> >
> > /* If pkt_dev->count is zero, then run forever */
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe netdev" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Sr. Network Kernel Developer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2015-05-06 8:44 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-01 5:12 [PATCH v3 net-next] pktgen: introduce 'rx' mode Alexei Starovoitov
2015-05-01 16:54 ` Eric Dumazet
2015-05-02 8:46 ` Jesper Dangaard Brouer
2015-05-02 9:44 ` Daniel Borkmann
2015-05-02 9:54 ` Jesper Dangaard Brouer
2015-05-02 10:30 ` Daniel Borkmann
2015-05-02 16:01 ` Alexei Starovoitov
2015-05-02 16:46 ` Jesper Dangaard Brouer
2015-05-02 17:07 ` Alexei Starovoitov
2015-05-05 18:15 ` Jesper Dangaard Brouer
2015-05-05 18:30 ` Alexei Starovoitov
2015-05-05 20:29 ` [PATCH 0/2] pktgen changes Jesper Dangaard Brouer
2015-05-05 20:29 ` [PATCH 1/2] pktgen: adjust flag NO_TIMESTAMP to be more pktgen compliant Jesper Dangaard Brouer
2015-05-05 20:30 ` [PATCH 2/2] pktgen: introduce xmit_mode 'rx_inject' Jesper Dangaard Brouer
2015-05-06 4:33 ` Alexei Starovoitov
2015-05-06 5:24 ` Jesper Dangaard Brouer
2015-05-06 10:17 ` Daniel Borkmann
2015-05-06 11:22 ` Jesper Dangaard Brouer
2015-05-06 5:32 ` Alexander Duyck
2015-05-06 8:44 ` Jesper Dangaard Brouer [this message]
2015-05-06 14:35 ` Alexei Starovoitov
2015-05-07 14:34 ` [PATCH v5 0/2] pktgen changes Jesper Dangaard Brouer
2015-05-07 14:34 ` [PATCH v5 1/2] pktgen: adjust flag NO_TIMESTAMP to be more pktgen compliant Jesper Dangaard Brouer
2015-05-07 14:35 ` [PATCH v5 2/2] pktgen: introduce xmit_mode '<start_xmit|netif_receive>' Jesper Dangaard Brouer
2015-05-07 16:28 ` Alexei Starovoitov
2015-05-07 17:11 ` Daniel Borkmann
2015-05-07 17:16 ` Alexei Starovoitov
2015-05-07 17:20 ` Daniel Borkmann
2015-05-08 13:40 ` Multiqueue pktgen (was: [PATCH v5 2/2] pktgen: introduce xmit_mode '<start_xmit|netif_receive>') Jesper Dangaard Brouer
2015-05-08 15:39 ` [PATCH v5 2/2] pktgen: introduce xmit_mode '<start_xmit|netif_receive>' Jesper Dangaard Brouer
2015-05-08 15:49 ` Multiqueue pktgen and ingress path (Was: [PATCH v5 2/2] pktgen: introduce xmit_mode '<start_xmit|netif_receive>') Jesper Dangaard Brouer
2015-05-08 15:56 ` Eric Dumazet
2015-05-08 16:53 ` Alexander Duyck
2015-05-08 17:00 ` Alexei Starovoitov
2015-05-08 18:21 ` Alexander Duyck
2015-05-08 15:57 ` [PATCH v5 2/2] pktgen: introduce xmit_mode '<start_xmit|netif_receive>' Eric Dumazet
2015-05-08 16:50 ` Alexei Starovoitov
2015-05-10 2:26 ` [PATCH v5 0/2] pktgen changes David Miller
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