> -----Original Message----- > From: dev [mailto:dev-boun...@openvswitch.org] On Behalf Of Zoltan Kiss > Sent: Monday, December 7, 2015 11:57 AM > To: Gray, Mark D; Aaron Conole; dev@openvswitch.org > Cc: Flavio Leitner > Subject: Re: [ovs-dev] [RFC 2/2] dpdk: Update INSTALL.DPDK.md to reflect new > config > > > > On 04/12/15 16:15, Gray, Mark D wrote: > >> 5. Start vswitchd: > >> > > >> >- DPDK configuration arguments can be passed to vswitchd via `--dpdk` > >> >- argument. This needs to be first argument passed to vswitchd process. > >> >- dpdk arg -c is ignored by ovs-dpdk, but it is a required parameter > >> >- for dpdk initialization. > >> >- > >> >+ DPDK configuration arguments can be passed to vswitchd via the > >> >Open_vSwitch > >> >+ other_config database. The recognized configuration options are > listed. > >> >+ > >> >+ * dpdk > >> >+ This is a boolean configuration option. A value of 'true' tells > >> >+ Open_vSwitch to initialize the DPDK EAL. A set of nominal defaults > are > >> >+ provided so that simply enabling this option will be sufficient to > configure > >> >+ DPDK enabled ports. > >> >+ * dpdk_core_mask > >> >+ This is DPDK's -c command line option, and specifies the core mask to > >> >+ the EAL. > > Why exactly do we need this again? We have "other_config:pmd-cpu-mask" > which > > should set the affinity of the pmd threads. The affinities of the other > standard pthreads > > should by a system administrator. Or, if the intention is that this would > allow us > > to set affinities for the other threads, then the name should be changed to > something > > more meaningful. > > > > My understanding is that OVS-DPDK doesn't really use any "lcore"'s from > DPDK, but rather creates its own threads, and set the lcore_id in > pmd_thread_setaffinity_cpu(). At least, I haven't seen any > rte_eal_[mp_]remote_launch() call in the code, so I think the -c option > should only have 1 core set for the master thread, everything else just > waste memory.
I agree. At present I see it only uses the lowest core in the -c option as the master thread. Aside from removing the command line args, I think we need to up level the docs so that an OVS user knows what the -c does and the (lack of) relationship with pmd-cpu-mask. I've seen a few examples recently where there is confusion between them. I can put in a patch to give a brief description in the docs for the short term, and we can keep this in mind for a bigger change like Aaron's. > _______________________________________________ > dev mailing list > dev@openvswitch.org > http://openvswitch.org/mailman/listinfo/dev _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
