diff options
Diffstat (limited to 'lib/librte_latencystats/rte_latencystats.c')
| -rw-r--r-- | lib/librte_latencystats/rte_latencystats.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/lib/librte_latencystats/rte_latencystats.c b/lib/librte_latencystats/rte_latencystats.c new file mode 100644 index 00000000..ce029a12 --- /dev/null +++ b/lib/librte_latencystats/rte_latencystats.c @@ -0,0 +1,360 @@ +/*- + * 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; +} |