lib/librte_ethdev/ethdev_profile.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2017 Intel Corporation
   3  */
   4
   5 #include "ethdev_profile.h"
   6
   7 /**
   8  * This conditional block enables RX queues profiling by tracking wasted
   9  * iterations, i.e. iterations which yielded no RX packets. Profiling is
  10  * performed using the Instrumentation and Tracing Technology (ITT) API,
  11  * employed by the Intel (R) VTune (TM) Amplifier.
  12  */
  13 #ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS
  14
  15 #include <ittnotify.h>
  16
  17 #define ITT_MAX_NAME_LEN (100)
  18
  19 /**
  20  * Auxiliary ITT structure belonging to Ethernet device and using to:
  21  *   -  track RX queue state to determine whether it is wasting loop iterations
  22  *   -  begin or end ITT task using task domain and task name (handle)
  23  */
  24 struct itt_profile_rx_data {
  25         /**
  26          * ITT domains for each queue.
  27          */
  28         __itt_domain *domains[RTE_MAX_QUEUES_PER_PORT];
  29         /**
  30          * ITT task names for each queue.
  31          */
  32         __itt_string_handle *handles[RTE_MAX_QUEUES_PER_PORT];
  33         /**
  34          * Flags indicating the queues state. Possible values:
  35          *   1 - queue is wasting iterations,
  36          *   0 - otherwise.
  37          */
  38         uint8_t queue_state[RTE_MAX_QUEUES_PER_PORT];
  39 };
  40
  41 /**
  42  * The pool of *itt_profile_rx_data* structures.
  43  */
  44 struct itt_profile_rx_data itt_rx_data[RTE_MAX_ETHPORTS];
  45
  46
  47 /**
  48  * This callback function manages ITT tasks collection on given port and queue.
  49  * It must be registered with rte_eth_add_rx_callback() to be called from
  50  * rte_eth_rx_burst(). To find more comments see rte_rx_callback_fn function
  51  * type declaration.
  52  */
  53 static uint16_t
  54 collect_itt_rx_burst_cb(uint16_t port_id, uint16_t queue_id,
  55         __rte_unused struct rte_mbuf *pkts[], uint16_t nb_pkts,
  56         __rte_unused uint16_t max_pkts, __rte_unused void *user_param)
  57 {
  58         if (unlikely(nb_pkts == 0)) {
  59                 if (!itt_rx_data[port_id].queue_state[queue_id]) {
  60                         __itt_task_begin(
  61                                 itt_rx_data[port_id].domains[queue_id],
  62                                 __itt_null, __itt_null,
  63                                 itt_rx_data[port_id].handles[queue_id]);
  64                         itt_rx_data[port_id].queue_state[queue_id] = 1;
  65                 }
  66         } else {
  67                 if (unlikely(itt_rx_data[port_id].queue_state[queue_id])) {
  68                         __itt_task_end(
  69                                 itt_rx_data[port_id].domains[queue_id]);
  70                         itt_rx_data[port_id].queue_state[queue_id] = 0;
  71                 }
  72         }
  73         return nb_pkts;
  74 }
  75
  76 /**
  77  * Initialization of itt_profile_rx_data for a given Ethernet device.
  78  * This function must be invoked when ethernet device is being configured.
  79  * Result will be stored in the global array *itt_rx_data*.
  80  *
  81  * @param port_id
  82  *  The port identifier of the Ethernet device.
  83  * @param port_name
  84  *  The name of the Ethernet device.
  85  * @param rx_queue_num
  86  *  The number of RX queues on specified port.
  87  *
  88  * @return
  89  *  - On success, zero.
  90  *  - On failure, a negative value.
  91  */
  92 static inline int
  93 itt_profile_rx_init(uint16_t port_id, char *port_name, uint8_t rx_queue_num)
  94 {
  95         uint16_t q_id;
  96
  97         for (q_id = 0; q_id < rx_queue_num; ++q_id) {
  98                 char domain_name[ITT_MAX_NAME_LEN];
  99
 100                 snprintf(domain_name, sizeof(domain_name),
 101                         "RXBurst.WastedIterations.Port_%s.Queue_%d",
 102                         port_name, q_id);
 103                 itt_rx_data[port_id].domains[q_id]
 104                         = __itt_domain_create(domain_name);
 105
 106                 char task_name[ITT_MAX_NAME_LEN];
 107
 108                 snprintf(task_name, sizeof(task_name),
 109                         "port id: %d; queue id: %d",
 110                         port_id, q_id);
 111                 itt_rx_data[port_id].handles[q_id]
 112                         = __itt_string_handle_create(task_name);
 113
 114                 itt_rx_data[port_id].queue_state[q_id] = 0;
 115
 116                 if (!rte_eth_add_rx_callback(
 117                         port_id, q_id, collect_itt_rx_burst_cb, NULL)) {
 118                         return -rte_errno;
 119                 }
 120         }
 121
 122         return 0;
 123 }
 124 #endif /* RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS */
 125
 126 int
 127 __rte_eth_profile_rx_init(__rte_unused uint16_t port_id,
 128         __rte_unused struct rte_eth_dev *dev)
 129 {
 130 #ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS
 131         return itt_profile_rx_init(
 132                 port_id, dev->data->name, dev->data->nb_rx_queues);
 133 #endif
 134         return 0;
 135 }