Hi Yigit, when you say "I guess it's possible" is that not common? I would think that the amount of traffic people would want to forward to Linux for normal DPDK applications would be quite small. If you had to have a core dedicated for KNI on each interface that would get very wasteful.
On Wed, Jun 8, 2016 at 12:31 PM, Ferruh Yigit <ferruh.yigit at intel.com> wrote: > On 6/8/2016 5:30 PM, Cliff Burdick wrote: > > Hi, I have an application with two sockets where each core I'm planning > to > > transmit and receive a fairly large amount of traffic per core. Each core > > right now handles a single queue of either TX or RX of a given port. > Across > > all the cores, I may be processing up to 12 ports. I also need to handle > > things like ARP and ping, so I'm going to add in the KNI driver to handle > > that. Since the amount of traffic I'm expecting that I'll need to forward > > to Linux is very small, it seems like I should be able to dedicate one > > lcore per socket to handle this functionality and have the dataplane > cores > > pass the traffic off to this core using rte_kni_tx_burst(). > > > > My question is, first of all, is this possible? It seems like I can > > configure the KNI driver to start in "single thread" mode. From that > point, > > I want to initialize one KNI device for each port, and have each kernel > > lcore on each processor handle that traffic. I believe if I call > > rte_kni_alloc with core_id set to the kernel lcore for each device, then > in > > the end I'll have something like 6 KNI devices on socket one being > handled > > by lcore 0, and 6 KNI devices on socket 2 being handled by lcore 31 as an > > example. Then my threads that are handling the dataplane tx/rx can simply > > be passed a pointer to their respective rte_kni device. Does this sound > > correct? > > If rte_kni module used "single thread" mode, kernel core_id is not used > at all. For single thread mode, a single thread created, this is used to > for all kni devices and not able to pin to any specific lcore. > > For what you have described, first need to insert module with > kthread_mode=multiple param. This will create a kernel thread per kni > interface. But I guess it is possible to provide same > rte_kni_conf->core_id for some of them, and yes rte_kni_conf->force_pin > is required, otherwise core_id is not useful. According your sample, > first 6 kni devices will have core_id value 0, and other 6 kni devices > will have core_id value 31, with all have force_bind set. This will > create 12 kernel threads, will bind 6 of them to core 0 and other 6 to > core 31. > > > > > Also, the sample says the core affinity needs to be set using taskset. Is > > that already taken care of with conf.core_id in rte_kni_alloc or do I > still > > need to set it? > > > > Thanks > > > >
