1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2017 Intel Corporation
3  */
4 
5 #include <rte_common.h>
6 #include <rte_ethdev.h>
7 #include <rte_malloc.h>
8 #include <rte_metrics.h>
9 #include <rte_bitrate.h>
10 
11 /*
12  * Persistent bit-rate data.
13  * @internal
14  */
15 struct rte_stats_bitrate {
16 	uint64_t last_ibytes;
17 	uint64_t last_obytes;
18 	uint64_t peak_ibits;
19 	uint64_t peak_obits;
20 	uint64_t mean_ibits;
21 	uint64_t mean_obits;
22 	uint64_t ewma_ibits;
23 	uint64_t ewma_obits;
24 };
25 
26 struct rte_stats_bitrates {
27 	struct rte_stats_bitrate port_stats[RTE_MAX_ETHPORTS];
28 	uint16_t id_stats_set;
29 };
30 
31 struct rte_stats_bitrates *
rte_stats_bitrate_create(void)32 rte_stats_bitrate_create(void)
33 {
34 	return rte_zmalloc(NULL, sizeof(struct rte_stats_bitrates),
35 		RTE_CACHE_LINE_SIZE);
36 }
37 
38 void
rte_stats_bitrate_free(struct rte_stats_bitrates * bitrate_data)39 rte_stats_bitrate_free(struct rte_stats_bitrates *bitrate_data)
40 {
41 	rte_free(bitrate_data);
42 }
43 
44 int
rte_stats_bitrate_reg(struct rte_stats_bitrates * bitrate_data)45 rte_stats_bitrate_reg(struct rte_stats_bitrates *bitrate_data)
46 {
47 	const char * const names[] = {
48 		"ewma_bits_in", "ewma_bits_out",
49 		"mean_bits_in", "mean_bits_out",
50 		"peak_bits_in", "peak_bits_out",
51 	};
52 	int return_value;
53 
54 	if (bitrate_data == NULL)
55 		return -EINVAL;
56 
57 	return_value = rte_metrics_reg_names(&names[0], RTE_DIM(names));
58 	if (return_value >= 0)
59 		bitrate_data->id_stats_set = return_value;
60 	return return_value;
61 }
62 
63 int
rte_stats_bitrate_calc(struct rte_stats_bitrates * bitrate_data,uint16_t port_id)64 rte_stats_bitrate_calc(struct rte_stats_bitrates *bitrate_data,
65 			uint16_t port_id)
66 {
67 	struct rte_stats_bitrate *port_data;
68 	struct rte_eth_stats eth_stats;
69 	int ret_code;
70 	uint64_t cnt_bits;
71 	int64_t delta;
72 	const int64_t alpha_percent = 20;
73 	uint64_t values[6];
74 	int ret;
75 
76 	if (bitrate_data == NULL)
77 		return -EINVAL;
78 
79 	ret_code = rte_eth_stats_get(port_id, &eth_stats);
80 	if (ret_code != 0)
81 		return ret_code;
82 
83 	port_data = &bitrate_data->port_stats[port_id];
84 
85 	/* Incoming bitrate. This is an iteratively calculated EWMA
86 	 * (Exponentially Weighted Moving Average) that uses a
87 	 * weighting factor of alpha_percent. An unsmoothed mean
88 	 * for just the current time delta is also calculated for the
89 	 * benefit of people who don't understand signal processing.
90 	 */
91 	cnt_bits = (eth_stats.ibytes - port_data->last_ibytes) << 3;
92 	port_data->last_ibytes = eth_stats.ibytes;
93 	if (cnt_bits > port_data->peak_ibits)
94 		port_data->peak_ibits = cnt_bits;
95 	delta = cnt_bits;
96 	delta -= port_data->ewma_ibits;
97 	/* The +-50 fixes integer rounding during division */
98 	if (delta > 0)
99 		delta = (delta * alpha_percent + 50) / 100;
100 	else
101 		delta = (delta * alpha_percent - 50) / 100;
102 	port_data->ewma_ibits += delta;
103 	/* Integer roundoff prevents EWMA between 0 and (100/alpha_percent)
104 	 * ever reaching zero in no-traffic conditions
105 	 */
106 	if (cnt_bits == 0 && delta == 0)
107 		port_data->ewma_ibits = 0;
108 	port_data->mean_ibits = cnt_bits;
109 
110 	/* Outgoing bitrate (also EWMA) */
111 	cnt_bits = (eth_stats.obytes - port_data->last_obytes) << 3;
112 	port_data->last_obytes = eth_stats.obytes;
113 	if (cnt_bits > port_data->peak_obits)
114 		port_data->peak_obits = cnt_bits;
115 	delta = cnt_bits;
116 	delta -= port_data->ewma_obits;
117 	if (delta > 0)
118 		delta = (delta * alpha_percent + 50) / 100;
119 	else
120 		delta = (delta * alpha_percent - 50) / 100;
121 	port_data->ewma_obits += delta;
122 	if (cnt_bits == 0 && delta == 0)
123 		port_data->ewma_obits = 0;
124 	port_data->mean_obits = cnt_bits;
125 
126 	values[0] = port_data->ewma_ibits;
127 	values[1] = port_data->ewma_obits;
128 	values[2] = port_data->mean_ibits;
129 	values[3] = port_data->mean_obits;
130 	values[4] = port_data->peak_ibits;
131 	values[5] = port_data->peak_obits;
132 	ret = rte_metrics_update_values(port_id, bitrate_data->id_stats_set,
133 		values, RTE_DIM(values));
134 	if (ret < 0)
135 		return ret;
136 
137 	return 0;
138 }
139