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From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: mst@redhat.com, netdev@vger.kernel.org, john.fastabend@gmail.com,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org, brouer@redhat.com
Subject: Re: [PATCH net-next 2/2] virtio-net: simplify XDP handling in small buffer
Date: Thu, 1 Mar 2018 10:15:53 +0100	[thread overview]
Message-ID: <20180301101553.55c4c6bd@redhat.com> (raw)
In-Reply-To: <dbbfd899-fb7e-c039-5c9a-0f3b6ce34b78@redhat.com>

On Thu, 1 Mar 2018 16:49:24 +0800
Jason Wang <jasowang@redhat.com> wrote:

> > 2. This can easily cause out-of-order packets.  
> 
> I may miss something, but it looks to me packets were still delivered
> in order? Or you mean the packets that was dropped by cpumap?

No. Packets can now travel two code paths to the egress device. (1) XDP
native via ndp_xdp_xmit via direct delivery into a lockfree/dedicated
TX queue, (2) via normal network stack which can involve being queue in
a qdisc.  Do you see the possibility of the reorder now?

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

  reply	other threads:[~2018-03-01  9:15 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-01  3:19 [PATCH net-next 0/2] virtio-net: re enable XDP_REDIRECT for mergeable buffer Jason Wang
2018-03-01  3:19 ` [PATCH net-next 1/2] " Jason Wang
2018-03-01  8:41   ` Jesper Dangaard Brouer
2018-03-01  9:11     ` Jason Wang
2018-03-01 13:36   ` Michael S. Tsirkin
2018-03-02  4:20     ` Jason Wang
2018-03-01  3:19 ` [PATCH net-next 2/2] virtio-net: simplify XDP handling in small buffer Jason Wang
2018-03-01  8:02   ` Jesper Dangaard Brouer
2018-03-01  8:49     ` Jason Wang
2018-03-01  9:15       ` Jesper Dangaard Brouer [this message]
2018-03-01  9:24         ` Jason Wang
2018-03-01  9:10 ` [PATCH net-next 0/2] virtio-net: re enable XDP_REDIRECT for mergeable buffer Jesper Dangaard Brouer
2018-03-01  9:23   ` Jason Wang
2018-03-01 10:35     ` Jesper Dangaard Brouer
2018-03-01 13:15       ` Jason Wang
2018-03-01 14:16         ` Jesper Dangaard Brouer
2018-03-02  4:17           ` Jason Wang
2018-03-01 13:40       ` Michael S. Tsirkin

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