--- /dev/null
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <stdbool.h>
+#include <math.h>
+
+#include <rte_mbuf.h>
+#include <rte_log.h>
+#include <rte_cycles.h>
+#include <rte_ethdev.h>
+#include <rte_metrics.h>
+#include <rte_memzone.h>
+#include <rte_lcore.h>
+
+#include "rte_latencystats.h"
+
+/** Nano seconds per second */
+#define NS_PER_SEC 1E9
+
+/** Clock cycles per nano second */
+static uint64_t
+latencystat_cycles_per_ns(void)
+{
+ return rte_get_timer_hz() / NS_PER_SEC;
+}
+
+/* Macros for printing using RTE_LOG */
+#define RTE_LOGTYPE_LATENCY_STATS RTE_LOGTYPE_USER1
+
+static const char *MZ_RTE_LATENCY_STATS = "rte_latencystats";
+static int latency_stats_index;
+static uint64_t samp_intvl;
+static uint64_t timer_tsc;
+static uint64_t prev_tsc;
+
+struct rte_latency_stats {
+ float min_latency; /**< Minimum latency in nano seconds */
+ float avg_latency; /**< Average latency in nano seconds */
+ float max_latency; /**< Maximum latency in nano seconds */
+ float jitter; /** Latency variation */
+};
+
+static struct rte_latency_stats *glob_stats;
+
+struct rxtx_cbs {
+ struct rte_eth_rxtx_callback *cb;
+};
+
+static struct rxtx_cbs rx_cbs[RTE_MAX_ETHPORTS][RTE_MAX_QUEUES_PER_PORT];
+static struct rxtx_cbs tx_cbs[RTE_MAX_ETHPORTS][RTE_MAX_QUEUES_PER_PORT];
+
+struct latency_stats_nameoff {
+ char name[RTE_ETH_XSTATS_NAME_SIZE];
+ unsigned int offset;
+};
+
+static const struct latency_stats_nameoff lat_stats_strings[] = {
+ {"min_latency_ns", offsetof(struct rte_latency_stats, min_latency)},
+ {"avg_latency_ns", offsetof(struct rte_latency_stats, avg_latency)},
+ {"max_latency_ns", offsetof(struct rte_latency_stats, max_latency)},
+ {"jitter_ns", offsetof(struct rte_latency_stats, jitter)},
+};
+
+#define NUM_LATENCY_STATS (sizeof(lat_stats_strings) / \
+ sizeof(lat_stats_strings[0]))
+
+int32_t
+rte_latencystats_update(void)
+{
+ unsigned int i;
+ float *stats_ptr = NULL;
+ uint64_t values[NUM_LATENCY_STATS] = {0};
+ int ret;
+
+ for (i = 0; i < NUM_LATENCY_STATS; i++) {
+ stats_ptr = RTE_PTR_ADD(glob_stats,
+ lat_stats_strings[i].offset);
+ values[i] = (uint64_t)floor((*stats_ptr)/
+ latencystat_cycles_per_ns());
+ }
+
+ ret = rte_metrics_update_values(RTE_METRICS_GLOBAL,
+ latency_stats_index,
+ values, NUM_LATENCY_STATS);
+ if (ret < 0)
+ RTE_LOG(INFO, LATENCY_STATS, "Failed to push the stats\n");
+
+ return ret;
+}
+
+static void
+rte_latencystats_fill_values(struct rte_metric_value *values)
+{
+ unsigned int i;
+ float *stats_ptr = NULL;
+
+ for (i = 0; i < NUM_LATENCY_STATS; i++) {
+ stats_ptr = RTE_PTR_ADD(glob_stats,
+ lat_stats_strings[i].offset);
+ values[i].key = i;
+ values[i].value = (uint64_t)floor((*stats_ptr)/
+ latencystat_cycles_per_ns());
+ }
+}
+
+static uint16_t
+add_time_stamps(uint8_t pid __rte_unused,
+ uint16_t qid __rte_unused,
+ struct rte_mbuf **pkts,
+ uint16_t nb_pkts,
+ uint16_t max_pkts __rte_unused,
+ void *user_cb __rte_unused)
+{
+ unsigned int i;
+ uint64_t diff_tsc, now;
+
+ /*
+ * For every sample interval,
+ * time stamp is marked on one received packet.
+ */
+ now = rte_rdtsc();
+ for (i = 0; i < nb_pkts; i++) {
+ diff_tsc = now - prev_tsc;
+ timer_tsc += diff_tsc;
+ if (timer_tsc >= samp_intvl) {
+ pkts[i]->timestamp = now;
+ timer_tsc = 0;
+ }
+ prev_tsc = now;
+ now = rte_rdtsc();
+ }
+
+ return nb_pkts;
+}
+
+static uint16_t
+calc_latency(uint8_t pid __rte_unused,
+ uint16_t qid __rte_unused,
+ struct rte_mbuf **pkts,
+ uint16_t nb_pkts,
+ void *_ __rte_unused)
+{
+ unsigned int i, cnt = 0;
+ uint64_t now;
+ float latency[nb_pkts];
+ static float prev_latency;
+ /*
+ * Alpha represents degree of weighting decrease in EWMA,
+ * a constant smoothing factor between 0 and 1. The value
+ * is used below for measuring average latency.
+ */
+ const float alpha = 0.2;
+
+ now = rte_rdtsc();
+ for (i = 0; i < nb_pkts; i++) {
+ if (pkts[i]->timestamp)
+ latency[cnt++] = now - pkts[i]->timestamp;
+ }
+
+ for (i = 0; i < cnt; i++) {
+ /*
+ * The jitter is calculated as statistical mean of interpacket
+ * delay variation. The "jitter estimate" is computed by taking
+ * the absolute values of the ipdv sequence and applying an
+ * exponential filter with parameter 1/16 to generate the
+ * estimate. i.e J=J+(|D(i-1,i)|-J)/16. Where J is jitter,
+ * D(i-1,i) is difference in latency of two consecutive packets
+ * i-1 and i.
+ * Reference: Calculated as per RFC 5481, sec 4.1,
+ * RFC 3393 sec 4.5, RFC 1889 sec.
+ */
+ glob_stats->jitter += (fabsf(prev_latency - latency[i])
+ - glob_stats->jitter)/16;
+ if (glob_stats->min_latency == 0)
+ glob_stats->min_latency = latency[i];
+ else if (latency[i] < glob_stats->min_latency)
+ glob_stats->min_latency = latency[i];
+ else if (latency[i] > glob_stats->max_latency)
+ glob_stats->max_latency = latency[i];
+ /*
+ * The average latency is measured using exponential moving
+ * average, i.e. using EWMA
+ * https://en.wikipedia.org/wiki/Moving_average
+ */
+ glob_stats->avg_latency +=
+ alpha * (latency[i] - glob_stats->avg_latency);
+ prev_latency = latency[i];
+ }
+
+ return nb_pkts;
+}
+
+int
+rte_latencystats_init(uint64_t app_samp_intvl,
+ rte_latency_stats_flow_type_fn user_cb)
+{
+ unsigned int i;
+ uint8_t pid;
+ uint16_t qid;
+ struct rxtx_cbs *cbs = NULL;
+ const uint8_t nb_ports = rte_eth_dev_count();
+ const char *ptr_strings[NUM_LATENCY_STATS] = {0};
+ const struct rte_memzone *mz = NULL;
+ const unsigned int flags = 0;
+
+ if (rte_memzone_lookup(MZ_RTE_LATENCY_STATS))
+ return -EEXIST;
+
+ /** Allocate stats in shared memory fo multi process support */
+ mz = rte_memzone_reserve(MZ_RTE_LATENCY_STATS, sizeof(*glob_stats),
+ rte_socket_id(), flags);
+ if (mz == NULL) {
+ RTE_LOG(ERR, LATENCY_STATS, "Cannot reserve memory: %s:%d\n",
+ __func__, __LINE__);
+ return -ENOMEM;
+ }
+
+ glob_stats = mz->addr;
+ samp_intvl = app_samp_intvl * latencystat_cycles_per_ns();
+
+ /** Register latency stats with stats library */
+ for (i = 0; i < NUM_LATENCY_STATS; i++)
+ ptr_strings[i] = lat_stats_strings[i].name;
+
+ latency_stats_index = rte_metrics_reg_names(ptr_strings,
+ NUM_LATENCY_STATS);
+ if (latency_stats_index < 0) {
+ RTE_LOG(DEBUG, LATENCY_STATS,
+ "Failed to register latency stats names\n");
+ return -1;
+ }
+
+ /** Register Rx/Tx callbacks */
+ for (pid = 0; pid < nb_ports; pid++) {
+ struct rte_eth_dev_info dev_info;
+ rte_eth_dev_info_get(pid, &dev_info);
+ for (qid = 0; qid < dev_info.nb_rx_queues; qid++) {
+ cbs = &rx_cbs[pid][qid];
+ cbs->cb = rte_eth_add_first_rx_callback(pid, qid,
+ add_time_stamps, user_cb);
+ if (!cbs->cb)
+ RTE_LOG(INFO, LATENCY_STATS, "Failed to "
+ "register Rx callback for pid=%d, "
+ "qid=%d\n", pid, qid);
+ }
+ for (qid = 0; qid < dev_info.nb_tx_queues; qid++) {
+ cbs = &tx_cbs[pid][qid];
+ cbs->cb = rte_eth_add_tx_callback(pid, qid,
+ calc_latency, user_cb);
+ if (!cbs->cb)
+ RTE_LOG(INFO, LATENCY_STATS, "Failed to "
+ "register Tx callback for pid=%d, "
+ "qid=%d\n", pid, qid);
+ }
+ }
+ return 0;
+}
+
+int
+rte_latencystats_uninit(void)
+{
+ uint8_t pid;
+ uint16_t qid;
+ int ret = 0;
+ struct rxtx_cbs *cbs = NULL;
+ const uint8_t nb_ports = rte_eth_dev_count();
+
+ /** De register Rx/Tx callbacks */
+ for (pid = 0; pid < nb_ports; pid++) {
+ struct rte_eth_dev_info dev_info;
+ rte_eth_dev_info_get(pid, &dev_info);
+ for (qid = 0; qid < dev_info.nb_rx_queues; qid++) {
+ cbs = &rx_cbs[pid][qid];
+ ret = rte_eth_remove_rx_callback(pid, qid, cbs->cb);
+ if (ret)
+ RTE_LOG(INFO, LATENCY_STATS, "failed to "
+ "remove Rx callback for pid=%d, "
+ "qid=%d\n", pid, qid);
+ }
+ for (qid = 0; qid < dev_info.nb_tx_queues; qid++) {
+ cbs = &tx_cbs[pid][qid];
+ ret = rte_eth_remove_tx_callback(pid, qid, cbs->cb);
+ if (ret)
+ RTE_LOG(INFO, LATENCY_STATS, "failed to "
+ "remove Tx callback for pid=%d, "
+ "qid=%d\n", pid, qid);
+ }
+ }
+
+ return 0;
+}
+
+int
+rte_latencystats_get_names(struct rte_metric_name *names, uint16_t size)
+{
+ unsigned int i;
+
+ if (names == NULL || size < NUM_LATENCY_STATS)
+ return NUM_LATENCY_STATS;
+
+ for (i = 0; i < NUM_LATENCY_STATS; i++)
+ snprintf(names[i].name, sizeof(names[i].name),
+ "%s", lat_stats_strings[i].name);
+
+ return NUM_LATENCY_STATS;
+}
+
+int
+rte_latencystats_get(struct rte_metric_value *values, uint16_t size)
+{
+ if (size < NUM_LATENCY_STATS || values == NULL)
+ return NUM_LATENCY_STATS;
+
+ if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+ const struct rte_memzone *mz;
+ mz = rte_memzone_lookup(MZ_RTE_LATENCY_STATS);
+ if (mz == NULL) {
+ RTE_LOG(ERR, LATENCY_STATS,
+ "Latency stats memzone not found\n");
+ return -ENOMEM;
+ }
+ glob_stats = mz->addr;
+ }
+
+ /* Retrieve latency stats */
+ rte_latencystats_fill_values(values);
+
+ return NUM_LATENCY_STATS;
+}
Code Review / deb_dpdk.git / blobdiff