On 16/06/2015 18:27, "Flavio Leitner" <f...@sysclose.org> wrote:
>On Mon, Jun 15, 2015 at 05:55:13PM +0000, Daniele Di Proietto wrote: >> On 15/06/2015 12:16, "Traynor, Kevin" <kevin.tray...@intel.com> wrote: >> >There is a dpdk patchset that contains a potential fix for this and >>lots >> >of >> >other changes, but I haven't tested yet. >> >>>https://urldefense.proofpoint.com/v2/url?u=http-3A__dpdk.org_ml_archives >>>_d >> >>>ev_2015-2DJune_018436.html&d=BQIFAg&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihV >>>MN >> >>>tXt-uEs&r=SmB5nZacmXNq0gKCC1s_Cw5yUNjxgD4v5kJqZ2uWLlE&m=FDVPKa2SqwpyYOTm >>>A2 >> >>>zGdscCPa1FVdQG3Zbr4tHrp38&s=fjg7wArWvYLJlgEGKijK6W6ECAxGk660UrPF3rAr4Rs& >>>e= > >I skimmed over the patchset and it is an ABI breaker, so I >think the policy demands to announce it on 2.1 and merge only >in 2.2 release. > >Maybe it is possible to separate the ol_flags fix into a >smaller and simple patch to be accepted as bugfix yet in 2.1. That'd be ideal. > >> >> > Otherwise, should we avoid using the vectorized version? >> >> >> >> that's debatable - from a performance view it may be better to leave >>it >> >>in >> >> and take the hit elsewhere for the time being if there's a >>possibility >> >>that >> >> it will be changed in DPDK later. >> > >> >With a loop to reset the rss after the rte_vhost_dequeue_burst() call >>I'm >> >seeing a drop of ~100kpps in vhost performance. Rx vectoristion gives a >> >gain >> >of about ~1 mpps on my system for the phy2phy cases. >> > >> >Using the ol_flags check is the right option when DPDK supports >>setting it >> >correctly with rx vectorisation. In the meantime there's choice of >>using >> >the >> >reset loop or removing rx vectorisation - what do you think? >> >> Thanks for sharing these results. I've observed that if OVS can't use >>the >> RSS >> hash and has to compute we lose ~2Mpps on a single flow phy2phy test. >> >> Despite this, I still think we should consider the ol_flags because: >> >> * DPDK drivers (other than ixgbe) should use ol_flags as well to mark >>the >> RSS hash as valid >> * ixgbe_recv_pkts_vec() will report PKT_RX_RSS_HASH in future releases >>(the >> patch you sent will be effective since DPDK 2.2, right?) > >I agree with the above. I just sent out a patch that uses the approach you suggested. I didn't modify dp_packet_get_rss_hash(), because other code relies on that to return a proper value (computed by the hardware or the software). > >> If the throughput with the non-vector rx routine is higher we can >>disable >> the vector rx as a temporary workaround. > >Could you point me to the vector and non-vector rx routines? >I feel like I am missing something. ixgbe_recv_pkts_vec() in drivers/net/ixgbe/ixgbe_rxtx.c is the vector rx. There are multiple version of the non-vector rx routine, I believe we used ixgbe_recv_pkts() in drivers/net/ixgbe/ixgbe_rxtx.c Thanks > >Thanks, >fbl > _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
