aboutsummaryrefslogtreecommitdiffstats
path: root/lib/librte_ether/ethdev_profile.c
blob: 0d1dcda36d6a31c5685f3f37e0dffbf04637c6b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2017 Intel Corporation
 */

#include "ethdev_profile.h"

/**
 * This conditional block enables RX queues profiling by tracking wasted
 * iterations, i.e. iterations which yielded no RX packets. Profiling is
 * performed using the Instrumentation and Tracing Technology (ITT) API,
 * employed by the Intel (R) VTune (TM) Amplifier.
 */
#ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS

#include <ittnotify.h>

#define ITT_MAX_NAME_LEN (100)

/**
 * Auxiliary ITT structure belonging to Ethernet device and using to:
 *   -  track RX queue state to determine whether it is wasting loop iterations
 *   -  begin or end ITT task using task domain and task name (handle)
 */
struct itt_profile_rx_data {
	/**
	 * ITT domains for each queue.
	 */
	__itt_domain *domains[RTE_MAX_QUEUES_PER_PORT];
	/**
	 * ITT task names for each queue.
	 */
	__itt_string_handle *handles[RTE_MAX_QUEUES_PER_PORT];
	/**
	 * Flags indicating the queues state. Possible values:
	 *   1 - queue is wasting iterations,
	 *   0 - otherwise.
	 */
	uint8_t queue_state[RTE_MAX_QUEUES_PER_PORT];
};

/**
 * The pool of *itt_profile_rx_data* structures.
 */
struct itt_profile_rx_data itt_rx_data[RTE_MAX_ETHPORTS];


/**
 * This callback function manages ITT tasks collection on given port and queue.
 * It must be registered with rte_eth_add_rx_callback() to be called from
 * rte_eth_rx_burst(). To find more comments see rte_rx_callback_fn function
 * type declaration.
 */
static uint16_t
collect_itt_rx_burst_cb(uint16_t port_id, uint16_t queue_id,
	__rte_unused struct rte_mbuf *pkts[], uint16_t nb_pkts,
	__rte_unused uint16_t max_pkts, __rte_unused void *user_param)
{
	if (unlikely(nb_pkts == 0)) {
		if (!itt_rx_data[port_id].queue_state[queue_id]) {
			__itt_task_begin(
				itt_rx_data[port_id].domains[queue_id],
				__itt_null, __itt_null,
				itt_rx_data[port_id].handles[queue_id]);
			itt_rx_data[port_id].queue_state[queue_id] = 1;
		}
	} else {
		if (unlikely(itt_rx_data[port_id].queue_state[queue_id])) {
			__itt_task_end(
				itt_rx_data[port_id].domains[queue_id]);
			itt_rx_data[port_id].queue_state[queue_id] = 0;
		}
	}
	return nb_pkts;
}

/**
 * Initialization of itt_profile_rx_data for a given Ethernet device.
 * This function must be invoked when ethernet device is being configured.
 * Result will be stored in the global array *itt_rx_data*.
 *
 * @param port_id
 *  The port identifier of the Ethernet device.
 * @param port_name
 *  The name of the Ethernet device.
 * @param rx_queue_num
 *  The number of RX queues on specified port.
 *
 * @return
 *  - On success, zero.
 *  - On failure, a negative value.
 */
static inline int
itt_profile_rx_init(uint16_t port_id, char *port_name, uint8_t rx_queue_num)
{
	uint16_t q_id;

	for (q_id = 0; q_id < rx_queue_num; ++q_id) {
		char domain_name[ITT_MAX_NAME_LEN];

		snprintf(domain_name, sizeof(domain_name),
			"RXBurst.WastedIterations.Port_%s.Queue_%d",
			port_name, q_id);
		itt_rx_data[port_id].domains[q_id]
			= __itt_domain_create(domain_name);

		char task_name[ITT_MAX_NAME_LEN];

		snprintf(task_name, sizeof(task_name),
			"port id: %d; queue id: %d",
			port_id, q_id);
		itt_rx_data[port_id].handles[q_id]
			= __itt_string_handle_create(task_name);

		itt_rx_data[port_id].queue_state[q_id] = 0;

		if (!rte_eth_add_rx_callback(
			port_id, q_id, collect_itt_rx_burst_cb, NULL)) {
			return -rte_errno;
		}
	}

	return 0;
}
#endif /* RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS */

int
__rte_eth_profile_rx_init(__rte_unused uint16_t port_id,
	__rte_unused struct rte_eth_dev *dev)
{
#ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS
	return itt_profile_rx_init(
		port_id, dev->data->name, dev->data->nb_rx_queues);
#endif
	return 0;
}