* Question on bulk dequeue support in virtual drivers
@ 2014-11-20 12:39 James Yonan
2014-11-20 15:26 ` Eric Dumazet
0 siblings, 1 reply; 2+ messages in thread
From: James Yonan @ 2014-11-20 12:39 UTC (permalink / raw)
To: Linux Netdev List
Consider a tunneling driver that receives packets in ndo_start_xmit,
encapsulates them in UDP, and forwards via ip_local_out. The
ndo_start_xmit implementation can implement bulking by looking at
skb->xmit_more. But then how to efficiently transmit the resulting
bulked list of encapsulated packets via UDP, so that the packets both
enter and leave the driver in bulked form? Is there an ip_local_out
alternative for bulked skb lists?
James
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Question on bulk dequeue support in virtual drivers
2014-11-20 12:39 Question on bulk dequeue support in virtual drivers James Yonan
@ 2014-11-20 15:26 ` Eric Dumazet
0 siblings, 0 replies; 2+ messages in thread
From: Eric Dumazet @ 2014-11-20 15:26 UTC (permalink / raw)
To: James Yonan; +Cc: Linux Netdev List
On Thu, 2014-11-20 at 05:39 -0700, James Yonan wrote:
> Consider a tunneling driver that receives packets in ndo_start_xmit,
> encapsulates them in UDP, and forwards via ip_local_out. The
> ndo_start_xmit implementation can implement bulking by looking at
> skb->xmit_more. But then how to efficiently transmit the resulting
> bulked list of encapsulated packets via UDP, so that the packets both
> enter and leave the driver in bulked form? Is there an ip_local_out
> alternative for bulked skb lists?
There is no such thing. Quite frankly it wont happen. Consider IP stacks
and netfilter, there is no provision for batches (other than GSO/TSO)
xmit_more addresses a specific hardware problem, it is not an
alternative for batches.
xmit_more will happen in your case in the last step, from qdisc to
ethernet device.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2014-11-20 15:26 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-11-20 12:39 Question on bulk dequeue support in virtual drivers James Yonan
2014-11-20 15:26 ` Eric Dumazet
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).