Hi All, It's a pity the performance gain couldn't be got without introducing the new function. But it is a clear performance gain none the less.
Regards, /Billy. > -----Original Message----- > From: Darrell Ball [mailto:[email protected]] > Sent: Wednesday, September 13, 2017 6:32 AM > To: Fischetti, Antonio <[email protected]>; [email protected] > Cc: O Mahony, Billy <[email protected]> > Subject: Re: [PATCH v5] dpif-netdev: Avoid reading RSS hash when EMC is > disabled > > These results look more clear: 2-3 % improvement for no EMC cases. > Maybe others have comments? > > > On 9/12/17, 9:34 AM, "[email protected]" > <[email protected]> wrote: > > 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. > > CC: Darrell Ball <[email protected]> > CC: Billy O Mahony <[email protected]> > Signed-off-by: Antonio Fischetti <[email protected]> > --- > V5 > - Removed OVS_LIKELY when checking cur_min. > > - I see a performance improvement for P2P and PVP tescases > when EMC is disabled, measurements are below. > > - I also tried different solutions, eg passing md_is_valid > to dpif_netdev_packet_get_rss_hash - or even the recirc_id > computed inside dp_execute_cb - as suggested by Billy but > I didn't see any performance benefit. > > - Rebased on Commit id > b9fedfa61f000f49500973d2a51e99a80d9cf9b8 > > - Each measurement was repeated 5 times and an average was > computed. > > > P2P testcase > ------------ > Flow setup: > table=0, in_port=dpdk0 actions=output:dpdk1 > table=0, in_port=dpdk1 actions=output:dpdk0 > > Mono-directional, 64B UDP packets. Traffic sent at line-rate. > PMD threads: 2 > Built with "-O2 -march=native -g" > > Measurements and average are in Mpps. > > Orig | 5 Measurments | Avg > ---------+------------------------------------------+--------- > With EMC | 11.39 11.37 11.46 11.35 11.39 | 11.39 > no EMC | 8.23 8.22 8.26 8.20 8.22 | 8.23 > > + patch | 5 Measurments | Avg > ---------+------------------------------------------+--------- > With EMC | 11.46 11.39 11.40 11.45 11.38 | 11.42 > no EMC | 8.42 8.41 8.37 8.43 8.37 | 8.40 > > > PVP testcase > ------------ > Flow setup: > table=0, in_port=dpdk0 actions=output:dpdkvhostuser0 > table=0, in_port=dpdkvhostuser0 actions=output:dpdk0 > table=0, in_port=dpdkvhostuser1 actions=output:dpdk1 > table=0, in_port=dpdk1 actions=output:dpdkvhostuser1 > > Bi-directional, 64B UDP packets. Traffic sent at line-rate. > PMD threads: 2 > Built with "-O2 -march=native -g" > > Measurements and average are in Mpps. > > Orig | 5 Measurments | Avg > ---------+------------------------------------------+--------- > With EMC | 4.59 4.60 4.46 4.59 4.59 | 4.57 > no EMC | 3.72 3.72 3.64 3.72 3.72 | 3.70 > > + patch | 5 Measurments | Avg > ---------+------------------------------------------+--------- > With EMC | 4.50 4.62 4.60 4.60 4.58 | 4.58 > no EMC | 3.78 3.86 3.84 3.84 3.83 | 3.83 > > > Recirculation testcase > ---------------------- > In a test setup with a firewall I didn't see any performance > difference between the original and the patch. > > > V4 > - reworked to remove dependencies from other patches in > patchset "Skip EMC for recirc pkts and other optimizations." > https://urldefense.proofpoint.com/v2/url?u=https- > 3A__mail.openvswitch.org_pipermail_ovs-2Ddev_2017- > 2DAugust_337320.html&d=DwIBAg&c=uilaK90D4TOVoH58JNXRgQ&r=BVhFA > 09CGX7JQ5Ih- > uZnsw&m=Mlu2yd3PFPpnA0HXsnY9Mq9JpsZYoS9_cSNEv6nMjsI&s=frcbor3lc > JkzFUS3Dl5Mmioaz43QeZOA6AwDWjO0Iac&e= > > - measurements were repeated with the latest head of master. > --- > 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 0ceef9d..baf65e8 100644 > --- a/lib/dpif-netdev.c > +++ b/lib/dpif-netdev.c > @@ -4765,6 +4765,22 @@ 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) > { > @@ -4899,10 +4915,18 @@ 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 (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
