On 08/27/2018 02:30 PM, Ilya Maximets wrote: > On 25.08.2018 13:00, Kevin Traynor wrote: >> Prior to OVS 2.9 automatic assignment of Rxqs to PMDs >> (i.e. CPUs) was done by round-robin. >> >> That was changed in OVS 2.9 to ordering the Rxqs based on >> their measured processing cycles. This was to assign the >> busiest Rxqs to different PMDs, improving aggregate >> throughput. >> >> For the most part the new scheme should be better, but >> there could be situations where a user prefers a simple >> round-robin scheme because Rxqs from a single port are >> more likely to be spread across multiple PMDs, and/or >> traffic is very bursty/unpredictable. >> >> Add 'pmd-rxq-assign' config to allow a user to select >> round-robin based assignment. >> >> Signed-off-by: Kevin Traynor <ktray...@redhat.com> >> Acked-by: Eelco Chaudron <echau...@redhat.com> >> --- >> >> V3: >> - Rolled in some style and vswitch.xml changes (Ilya) >> - Set cycles mode by default on wrong config (Ilya) >> >> V2: >> - simplified nextpmd change (Eelco) >> - removed confusing doc sentence (Eelco) >> - fixed commit msg (Ilya) >> - made change in pmd-rxq-assign value also perform re-assignment (Ilya) >> - renamed to roundrobin mode (Ilya) >> - moved vswitch.xml changes to right config section (Ilya) >> - comment/log updates >> - moved NEWS update to separate patch as it's been changing on master >> >> Documentation/topics/dpdk/pmd.rst | 33 +++++++++++++--- >> lib/dpif-netdev.c | 83 >> +++++++++++++++++++++++++++++---------- >> tests/pmd.at | 12 +++++- >> vswitchd/vswitch.xml | 24 +++++++++++ >> 4 files changed, 123 insertions(+), 29 deletions(-) >> >> diff --git a/Documentation/topics/dpdk/pmd.rst >> b/Documentation/topics/dpdk/pmd.rst >> index 5f0671e..dd9172d 100644 >> --- a/Documentation/topics/dpdk/pmd.rst >> +++ b/Documentation/topics/dpdk/pmd.rst >> @@ -113,10 +113,15 @@ means that this thread will only poll the *pinned* Rx >> queues. >> >> If ``pmd-rxq-affinity`` is not set for Rx queues, they will be assigned to >> PMDs >> -(cores) automatically. Where known, the processing cycles that have been >> stored >> -for each Rx queue will be used to assign Rx queue to PMDs based on a round >> -robin of the sorted Rx queues. For example, take the following example, >> where >> -there are five Rx queues and three cores - 3, 7, and 8 - available and the >> -measured usage of core cycles per Rx queue over the last interval is seen to >> -be: >> +(cores) automatically. >> + >> +The algorithm used to automatically assign Rxqs to PMDs can be set by:: >> + >> + $ ovs-vsctl set Open_vSwitch . other_config:pmd-rxq-assign=<assignment> >> + >> +By default, ``cycles`` assignment is used where the Rxqs will be ordered by >> +their measured processing cycles, and then be evenly assigned in descending >> +order to PMDs based on an up/down walk of the PMDs. For example, where there >> +are five Rx queues and three cores - 3, 7, and 8 - available and the >> measured >> +usage of core cycles per Rx queue over the last interval is seen to be: >> >> - Queue #0: 30% >> @@ -132,4 +137,20 @@ The Rx queues will be assigned to the cores in the >> following order:: >> Core 8: Q3 (60%) | Q0 (30%) >> >> +Alternatively, ``roundrobin`` assignment can be used, where the Rxqs are >> +assigned to PMDs in a round-robined fashion. This algorithm was used by >> +default prior to OVS 2.9. For example, given the following ports and queues: >> + >> +- Port #0 Queue #0 (P0Q0) >> +- Port #0 Queue #1 (P0Q1) >> +- Port #1 Queue #0 (P1Q0) >> +- Port #1 Queue #1 (P1Q1) >> +- Port #1 Queue #2 (P1Q2) >> + >> +The Rx queues may be assigned to the cores in the following order:: >> + >> + Core 3: P0Q0 | P1Q1 >> + Core 7: P0Q1 | P1Q2 >> + Core 8: P1Q0 | >> + >> To see the current measured usage history of PMD core cycles for each Rx >> queue:: >> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c >> index 7f836bb..8f004c5 100644 >> --- a/lib/dpif-netdev.c >> +++ b/lib/dpif-netdev.c >> @@ -342,4 +342,6 @@ struct dp_netdev { >> struct id_pool *tx_qid_pool; >> struct ovs_mutex tx_qid_pool_mutex; >> + /* Use measured cycles for rxq to pmd assignment. */ >> + bool pmd_rxq_assign_cyc; >> >> /* Protects the access of the 'struct dp_netdev_pmd_thread' >> @@ -1493,4 +1495,5 @@ create_dp_netdev(const char *name, const struct >> dpif_class *class, >> >> cmap_init(&dp->poll_threads); >> + dp->pmd_rxq_assign_cyc = true; >> >> ovs_mutex_init(&dp->tx_qid_pool_mutex); >> @@ -3717,4 +3720,6 @@ dpif_netdev_set_config(struct dpif *dpif, const struct >> smap *other_config) >> struct dp_netdev *dp = get_dp_netdev(dpif); >> const char *cmask = smap_get(other_config, "pmd-cpu-mask"); >> + const char *pmd_rxq_assign = smap_get_def(other_config, >> "pmd-rxq-assign", >> + "cycles"); >> unsigned long long insert_prob = >> smap_get_ullong(other_config, "emc-insert-inv-prob", >> @@ -3779,4 +3784,18 @@ dpif_netdev_set_config(struct dpif *dpif, const >> struct smap *other_config) >> } >> } >> + >> + bool pmd_rxq_assign_cyc = !strcmp(pmd_rxq_assign, "cycles"); >> + if (!pmd_rxq_assign_cyc && strcmp(pmd_rxq_assign, "roundrobin")) { >> + VLOG_WARN("Unsupported Rxq to PMD assignment mode: " >> + "defaulting to 'cycles'."); > > Have you missed the actual printing of the wrong value? > Or that is what you wanted? >
It was what I intended. If someone puts in junk, I didn't want to be adding it to the log. >> + pmd_rxq_assign_cyc = true; >> + pmd_rxq_assign = "cycles"; >> + } >> + if (dp->pmd_rxq_assign_cyc != pmd_rxq_assign_cyc) { >> + dp->pmd_rxq_assign_cyc = pmd_rxq_assign_cyc; >> + VLOG_INFO("Rxq to PMD assignment mode changed to: \'%s\'.", >> + pmd_rxq_assign); >> + dp_netdev_request_reconfigure(dp); >> + } >> return 0; >> } >> @@ -4249,8 +4268,16 @@ rr_numa_list_populate(struct dp_netdev *dp, struct >> rr_numa_list *rr) >> } >> >> -/* Returns the next pmd from the numa node in >> - * incrementing or decrementing order. */ >> +/* >> + * Returns the next pmd from the numa node. >> + * >> + * If 'updown' is 'true' it will alternate between selecting the next pmd in >> + * either an up or down walk, switching between up/down when the first or >> last >> + * core is reached. e.g. 1,2,3,3,2,1,1,2... >> + * >> + * If 'updown' is 'false' it will select the next pmd wrapping around when >> last >> + * core reached. e.g. 1,2,3,1,2,3,1,2... >> + */ >> static struct dp_netdev_pmd_thread * >> -rr_numa_get_pmd(struct rr_numa *numa) >> +rr_numa_get_pmd(struct rr_numa *numa, bool updown) >> { >> int numa_idx = numa->cur_index; >> @@ -4260,5 +4287,9 @@ rr_numa_get_pmd(struct rr_numa *numa) >> if (numa->cur_index == numa->n_pmds-1) { >> /* Reached the last pmd. */ >> - numa->idx_inc = false; >> + if (updown) { >> + numa->idx_inc = false; >> + } else { >> + numa->cur_index = 0; >> + } >> } else { >> numa->cur_index++; >> @@ -4323,7 +4354,4 @@ compare_rxq_cycles(const void *a, const void *b) >> * pmds to unpinned queues. >> * >> - * If 'pinned' is false queues will be sorted by processing cycles they are >> - * consuming and then assigned to pmds in round robin order. >> - * >> * The function doesn't touch the pmd threads, it just stores the assignment >> * in the 'pmd' member of each rxq. */ >> @@ -4338,4 +4366,5 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) >> OVS_REQUIRES(dp->port_mutex) >> struct rr_numa *numa = NULL; >> int numa_id; >> + bool assign_cyc = dp->pmd_rxq_assign_cyc; >> >> HMAP_FOR_EACH (port, node, &dp->ports) { >> @@ -4368,10 +4397,13 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) >> OVS_REQUIRES(dp->port_mutex) >> rxqs = xrealloc(rxqs, sizeof *rxqs * (n_rxqs + 1)); >> } >> - /* Sum the queue intervals and store the cycle history. */ >> - for (unsigned i = 0; i < PMD_RXQ_INTERVAL_MAX; i++) { >> - cycle_hist += dp_netdev_rxq_get_intrvl_cycles(q, i); >> - } >> - dp_netdev_rxq_set_cycles(q, RXQ_CYCLES_PROC_HIST, >> cycle_hist); >> >> + if (assign_cyc) { >> + /* Sum the queue intervals and store the cycle history. >> */ >> + for (unsigned i = 0; i < PMD_RXQ_INTERVAL_MAX; i++) { >> + cycle_hist += dp_netdev_rxq_get_intrvl_cycles(q, i); >> + } >> + dp_netdev_rxq_set_cycles(q, RXQ_CYCLES_PROC_HIST, >> + cycle_hist); >> + } >> /* Store the queue. */ >> rxqs[n_rxqs++] = q; >> @@ -4380,5 +4412,5 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) >> OVS_REQUIRES(dp->port_mutex) >> } >> >> - if (n_rxqs > 1) { >> + if (n_rxqs > 1 && assign_cyc) { >> /* Sort the queues in order of the processing cycles >> * they consumed during their last pmd interval. */ >> @@ -4404,5 +4436,5 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) >> OVS_REQUIRES(dp->port_mutex) >> continue; >> } >> - rxqs[i]->pmd = rr_numa_get_pmd(non_local_numa); >> + rxqs[i]->pmd = rr_numa_get_pmd(non_local_numa, assign_cyc); >> VLOG_WARN("There's no available (non-isolated) pmd thread " >> "on numa node %d. Queue %d on port \'%s\' will " >> @@ -4413,11 +4445,20 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) >> OVS_REQUIRES(dp->port_mutex) >> rxqs[i]->pmd->core_id, rxqs[i]->pmd->numa_id); >> } else { >> - rxqs[i]->pmd = rr_numa_get_pmd(numa); >> - VLOG_INFO("Core %d on numa node %d assigned port \'%s\' " >> - "rx queue %d (measured processing cycles %"PRIu64").", >> - rxqs[i]->pmd->core_id, numa_id, >> - netdev_rxq_get_name(rxqs[i]->rx), >> - netdev_rxq_get_queue_id(rxqs[i]->rx), >> - dp_netdev_rxq_get_cycles(rxqs[i], RXQ_CYCLES_PROC_HIST)); >> + rxqs[i]->pmd = rr_numa_get_pmd(numa, assign_cyc); >> + if (assign_cyc) { >> + VLOG_INFO("Core %d on numa node %d assigned port \'%s\' " >> + "rx queue %d " >> + "(measured processing cycles %"PRIu64").", >> + rxqs[i]->pmd->core_id, numa_id, >> + netdev_rxq_get_name(rxqs[i]->rx), >> + netdev_rxq_get_queue_id(rxqs[i]->rx), >> + dp_netdev_rxq_get_cycles(rxqs[i], >> + RXQ_CYCLES_PROC_HIST)); >> + } else { >> + VLOG_INFO("Core %d on numa node %d assigned port \'%s\' " >> + "rx queue %d.", rxqs[i]->pmd->core_id, numa_id, >> + netdev_rxq_get_name(rxqs[i]->rx), >> + netdev_rxq_get_queue_id(rxqs[i]->rx)); >> + } >> } >> } >> diff --git a/tests/pmd.at b/tests/pmd.at >> index 4cae6c8..1f952f3 100644 >> --- a/tests/pmd.at >> +++ b/tests/pmd.at >> @@ -62,5 +62,6 @@ m4_define([CHECK_PMD_THREADS_CREATED], [ >> >> m4_define([SED_NUMA_CORE_PATTERN], ["s/\(numa_id \)[[0-9]]*\( core_id >> \)[[0-9]]*:/\1<cleared>\2<cleared>:/"]) >> -m4_define([SED_NUMA_CORE_QUEUE_PATTERN], ["s/1 2 5 6/<group>/;s/0 3 4 >> 7/<group>/"]) >> +m4_define([SED_NUMA_CORE_QUEUE_CYC_PATTERN], ["s/1 2 5 6/<group>/;s/0 3 4 >> 7/<group>/"]) >> +m4_define([SED_NUMA_CORE_QUEUE_PQ_PATTERN], ["s/1 3 5 7/<group>/;s/0 2 4 >> 6/<group>/"]) >> m4_define([DUMMY_NUMA], [--dummy-numa="0,0,0,0"]) >> >> @@ -146,9 +147,16 @@ pmd thread numa_id <cleared> core_id <cleared>: >> ]) >> >> +AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-rxq-assign=cycles]) >> TMP=$(cat ovs-vswitchd.log | wc -l | tr -d [[:blank:]]) >> AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x3]) >> CHECK_PMD_THREADS_CREATED([2], [], [+$TMP]) >> >> -AT_CHECK([ovs-appctl dpif-netdev/pmd-rxq-show | sed >> ':a;/AVAIL$/{N;s/\n//;ba;}' | parse_pmd_rxq_show_group | sed >> SED_NUMA_CORE_QUEUE_PATTERN], [0], [dnl >> +AT_CHECK([ovs-appctl dpif-netdev/pmd-rxq-show | sed >> ':a;/AVAIL$/{N;s/\n//;ba;}' | parse_pmd_rxq_show_group | sed >> SED_NUMA_CORE_QUEUE_CYC_PATTERN], [0], [dnl >> +port: p0 queue-id: <group> >> +port: p0 queue-id: <group> >> +]) >> + >> +AT_CHECK([ovs-vsctl set Open_vSwitch . >> other_config:pmd-rxq-assign=roundrobin]) >> +AT_CHECK([ovs-appctl dpif-netdev/pmd-rxq-show | sed >> ':a;/AVAIL$/{N;s/\n//;ba;}' | parse_pmd_rxq_show_group | sed >> SED_NUMA_CORE_QUEUE_PQ_PATTERN], [0], [dnl >> port: p0 queue-id: <group> >> port: p0 queue-id: <group> >> diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml >> index 0cd8520..2439b24 100644 >> --- a/vswitchd/vswitch.xml >> +++ b/vswitchd/vswitch.xml >> @@ -425,4 +425,28 @@ >> </column> >> >> + <column name="other_config" key="pmd-rxq-assign" >> + type='{"type": "string", >> + "enum": ["set", ["cycles", "roundrobin"]]}'> >> + <p> >> + Specifies how RX queues will be automatically assigned to CPU >> cores. >> + Options: >> + <dl> >> + <dt><code>cycles</code></dt> >> + <dd>Rxqs will be sorted by order of measured processing cycles >> + before being assigned to CPU cores.</dd> >> + <dt><code>roundrobin</code></dt> >> + <dd>Rxqs will be round-robined across CPU cores.</dd> >> + </dl> >> + </p> >> + <p> >> + The default value is <code>cycles</code>. >> + </p> >> + <p> >> + Changing this value will affect an automatic re-assignment of >> Rxqs to >> + CPUs. Note: Rxqs mapped to CPU cores with >> + <code>pmd-rxq-affinity</code> are unaffected. >> + </p> >> + </column> >> + >> <column name="other_config" key="n-handler-threads" >> type='{"type": "integer", "minInteger": 1}'> >> _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev