When EMC is disabled the reading of RSS hash is skipped. Also, for packets that are not recirculated it retrieves the hash value without considering the recirc id.
Signed-off-by: Antonio Fischetti <[email protected]> --- V4 - reworked to remove dependencies from other patches in patchset "Skip EMC for recirc pkts and other optimizations." https://mail.openvswitch.org/pipermail/ovs-dev/2017-August/337320.html - measurements were repeated with the latest head of master. Port-to-Port Test ================= Software built with "-O2 -march=native -g". I measured the Rx rate regardless of pkt loss by sending 1 UDP flow, 64B packets, at the line-rate. 2 PMDs with 3 Tx queues. Flows setup: in_port=dpdk0 actions=output:dpdk1 in_port=dpdk1 actions=output:dpdk0 Results ------- Values are for the Rx rate in Mpps, regardless of packet loss. RSS column: Yes: RSS hash is provided by the NIC No: RSS is disabled and the 5-tuple hash must be computed in software. Note: to simulate RSS disabled I added the line dp_packet_rss_valid(struct dp_packet *p) { +return false; #ifdef DPDK_NETDEV EMC column: Yes: default probability insertion, No: EMC disabled. Orig means Commit ID: 75f9e007e7f7eb91461e238f882d1c539c56bb8d +--------------+----------------+ +-----+-----+ Orig | Orig + this | | RSS | EMC | | patch | +-----+-----+--------------+----------------+ | Yes | Yes | 12.02, 11.38 | 12.18, 11.32 | | Yes | No | 8.35, 8.36 | 8.36, 8.38 | +-----+-----+--------------+----------------+ | No | Yes | 9.91, 11.15 | 9.84, 11.08 | | No | No | 7.83, 7.87 | 8.33, 8.35 | +-----+-----+--------------+----------------+ --- lib/dpif-netdev.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index e2cd931..1157998 100644 --- a/lib/dpif-netdev.c +++ b/lib/dpif-netdev.c @@ -4567,6 +4567,22 @@ dp_netdev_upcall(struct dp_netdev_pmd_thread *pmd, struct dp_packet *packet_, } static inline uint32_t +dpif_netdev_packet_get_rss_hash_orig_pkt(struct dp_packet *packet, + const struct miniflow *mf) +{ + uint32_t hash; + + if (OVS_LIKELY(dp_packet_rss_valid(packet))) { + hash = dp_packet_get_rss_hash(packet); + } else { + hash = miniflow_hash_5tuple(mf, 0); + dp_packet_set_rss_hash(packet, hash); + } + + return hash; +} + +static inline uint32_t dpif_netdev_packet_get_rss_hash(struct dp_packet *packet, const struct miniflow *mf) { @@ -4701,10 +4717,18 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, } miniflow_extract(packet, &key->mf); key->len = 0; /* Not computed yet. */ - key->hash = dpif_netdev_packet_get_rss_hash(packet, &key->mf); - - /* If EMC is disabled skip emc_lookup */ - flow = (cur_min == 0) ? NULL: emc_lookup(flow_cache, key); + /* If EMC is disabled skip hash computation and emc_lookup */ + if (OVS_LIKELY(cur_min)) { + if (!md_is_valid) { + key->hash = dpif_netdev_packet_get_rss_hash_orig_pkt(packet, + &key->mf); + } else { + key->hash = dpif_netdev_packet_get_rss_hash(packet, &key->mf); + } + flow = emc_lookup(flow_cache, key); + } else { + flow = NULL; + } if (OVS_LIKELY(flow)) { dp_netdev_queue_batches(packet, flow, &key->mf, batches, n_batches); -- 2.4.11 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
