diff options
Diffstat (limited to 'src/plugins/perfmon/arm/bundle/branch_pred.c')
-rw-r--r-- | src/plugins/perfmon/arm/bundle/branch_pred.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/plugins/perfmon/arm/bundle/branch_pred.c b/src/plugins/perfmon/arm/bundle/branch_pred.c new file mode 100644 index 00000000000..7ab656f2758 --- /dev/null +++ b/src/plugins/perfmon/arm/bundle/branch_pred.c @@ -0,0 +1,140 @@ +/* + * Copyright (c) 2022 Arm and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/vnet.h> +#include <vppinfra/linux/sysfs.h> +#include <perfmon/perfmon.h> +#include <perfmon/arm/events.h> + +/* as per .events[n] in PERFMON_REGISTER_BUNDLE */ +enum +{ + BR_RETIRED, + BR_MIS_PRED_RETIRED, + BR_PRED, + BR_MIS_PRED +}; + +static u8 * +format_arm_branch_pred (u8 *s, va_list *args) +{ + perfmon_node_stats_t *ns = va_arg (*args, perfmon_node_stats_t *); + int row = va_arg (*args, int); + + switch (row) + { + case 0: + s = format (s, "%.2f", (f64) ns->value[BR_RETIRED] / ns->n_calls); + break; + + case 1: + s = format (s, "%.2f", (f64) ns->value[BR_RETIRED] / ns->n_packets); + break; + + case 2: + s = + format (s, "%.2f", (f64) ns->value[BR_MIS_PRED_RETIRED] / ns->n_calls); + break; + + case 3: + s = format (s, "%.2f", + (f64) ns->value[BR_MIS_PRED_RETIRED] / ns->n_packets); + break; + + case 4: + s = + format (s, "%.2f%%", + (ns->value[BR_RETIRED] ? (f64) ns->value[BR_MIS_PRED_RETIRED] / + ns->value[BR_RETIRED] * 100 : + 0)); + break; + + case 5: + s = format (s, "%.2f", (f64) ns->value[BR_PRED] / ns->n_calls); + break; + + case 6: + s = format (s, "%.2f", (f64) ns->value[BR_PRED] / ns->n_packets); + break; + + case 7: + s = format (s, "%.2f", (f64) ns->value[BR_MIS_PRED] / ns->n_calls); + break; + + case 8: + s = format (s, "%.2f", (f64) ns->value[BR_MIS_PRED] / ns->n_packets); + break; + + case 9: + s = format (s, "%.2f%%", + (ns->value[BR_PRED] ? + (f64) ns->value[BR_MIS_PRED] / ns->value[BR_PRED] * 100 : + 0)); + break; + + case 10: + s = format (s, "%llu", ns->n_packets); + break; + } + return s; +} + +PERFMON_REGISTER_BUNDLE (arm_branch_pred) = { + .name = "branch-pred", + .description = "Branch (mis)predictions per call/packet", + .source = "arm", + .type = PERFMON_BUNDLE_TYPE_NODE, + .events[0] = ARMV8_PMUV3_BR_RETIRED, + .events[1] = ARMV8_PMUV3_BR_MIS_PRED_RETIRED, + .events[2] = ARMV8_PMUV3_BR_PRED, + .events[3] = ARMV8_PMUV3_BR_MIS_PRED, + .n_events = 4, + .n_columns = 11, + .format_fn = format_arm_branch_pred, + .column_headers = PERFMON_STRINGS ("[1.1]", "[1.2]", "[1.3]", "[1.4]", "\%", + "[2.1]", "[2.2]", "[2.3]", "[2.4]", "\%", + "pkts"), + /* + * set a bit for every event used in each column + * this allows us to disable columns at bundle registration if an + * event is not supported + */ + .column_events = PERFMON_COLUMN_EVENTS ( + SET_BIT (BR_RETIRED), SET_BIT (BR_RETIRED), SET_BIT (BR_MIS_PRED_RETIRED), + SET_BIT (BR_MIS_PRED_RETIRED), + SET_BIT (BR_RETIRED) | SET_BIT (BR_MIS_PRED_RETIRED), SET_BIT (BR_PRED), + SET_BIT (BR_PRED), SET_BIT (BR_MIS_PRED), SET_BIT (BR_MIS_PRED), + SET_BIT (BR_PRED) | SET_BIT (BR_MIS_PRED), 0), + .footer = + "An instruction that has been executed and retired is defined to\n" + "be architecturally executed. When a PE can perform speculative\n" + "execution, an instruction is not architecturally executed if the\n" + "PE discards the results of the speculative execution.\n\n" + "Per node statistics:\n" + "[1] Branch instruction architecturally executed\n" + " [1.1] Branches/call\n" + " [1.2] Branches/pkt\n" + " [1.3] Mispredicted/call \n" + " [1.4] Mispredicted/pkt\n" + " [\%] Percentage of branches mispredicted\n" + "[2] Predictable branch speculatively executed\n" + " [2.1] Branches/call\n" + " [2.2] Branches/pkt\n" + " [2.3] Mispredicted/call \n" + " [2.4] Mispredicted/pkt\n" + " [\%] Percentage of branches mispredicted\n\n" + "- See Armv8-A Architecture Reference Manual, D7.10 PMU events and" + " event numbers for full description.\n" +}; |