Messages in this thread | | | Date | Thu, 30 May 2013 08:58:33 +0300 | From | Eliezer Tamir <> | Subject | Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling |
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On 29/05/2013 22:08, Eric Dumazet wrote: > On Wed, 2013-05-29 at 21:52 +0300, Or Gerlitz wrote: >> Eliezer Tamir <eliezer.tamir@linux.intel.com> wrote: >>> Or Gerlitz wrote: >> >>>> Unlike with TCP sockets, UDP sockets may receive packets from multiple >>>> sources and hence the receiving context may be steered to be executed >>>> on different cores through RSS or other Flow-Steering HW mechanisms >>>> which could mean different napi contexts for the same socket, is that >>>> a problem here? what's the severity? >> >>> Nothing will break if you poll on the wrong queue. >>> Your data will come through normal NAPI processing of the right queue. >> >> Can you elaborate a little further, why you call this "wrong" and "right"? >> -- > > This definitely need some documentation, because before llpoll, device > RX path was serviced by the cpu receiving the harwdare interrupt. > > So the "wrong" queue could add false sharing, and wrong NUMA > allocations.
Yes, To work properly when you have more than one NUMA node, you have to have packet steering set up, either by your NIC or by HW accelerated RFS.
I would like to add a short writeup of the design and suggested configuration. Where should it go?
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