aboutsummaryrefslogtreecommitdiff
path: root/lib/dim/net_dim.c
blob: 53f6b9c6e9366200906c8e49a98d2e37161fa51b (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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
 * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
 */

#include <linux/dim.h>

/*
 * Net DIM profiles:
 *        There are different set of profiles for each CQ period mode.
 *        There are different set of profiles for RX/TX CQs.
 *        Each profile size must be of NET_DIM_PARAMS_NUM_PROFILES
 */
#define NET_DIM_PARAMS_NUM_PROFILES 5
#define NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE 256
#define NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE 128
#define NET_DIM_DEF_PROFILE_CQE 1
#define NET_DIM_DEF_PROFILE_EQE 1

#define NET_DIM_RX_EQE_PROFILES { \
	{.usec = 1,   .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
	{.usec = 8,   .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
	{.usec = 64,  .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
	{.usec = 128, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
	{.usec = 256, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}  \
}

#define NET_DIM_RX_CQE_PROFILES { \
	{.usec = 2,  .pkts = 256,},             \
	{.usec = 8,  .pkts = 128,},             \
	{.usec = 16, .pkts = 64,},              \
	{.usec = 32, .pkts = 64,},              \
	{.usec = 64, .pkts = 64,}               \
}

#define NET_DIM_TX_EQE_PROFILES { \
	{.usec = 1,   .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,},  \
	{.usec = 8,   .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,},  \
	{.usec = 32,  .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,},  \
	{.usec = 64,  .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,},  \
	{.usec = 128, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}   \
}

#define NET_DIM_TX_CQE_PROFILES { \
	{.usec = 5,  .pkts = 128,},  \
	{.usec = 8,  .pkts = 64,},  \
	{.usec = 16, .pkts = 32,},  \
	{.usec = 32, .pkts = 32,},  \
	{.usec = 64, .pkts = 32,}   \
}

static const struct dim_cq_moder
rx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
	NET_DIM_RX_EQE_PROFILES,
	NET_DIM_RX_CQE_PROFILES,
};

static const struct dim_cq_moder
tx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
	NET_DIM_TX_EQE_PROFILES,
	NET_DIM_TX_CQE_PROFILES,
};

struct dim_cq_moder
net_dim_get_rx_moderation(u8 cq_period_mode, int ix)
{
	struct dim_cq_moder cq_moder = rx_profile[cq_period_mode][ix];

	cq_moder.cq_period_mode = cq_period_mode;
	return cq_moder;
}
EXPORT_SYMBOL(net_dim_get_rx_moderation);

struct dim_cq_moder
net_dim_get_def_rx_moderation(u8 cq_period_mode)
{
	u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
			NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;

	return net_dim_get_rx_moderation(cq_period_mode, profile_ix);
}
EXPORT_SYMBOL(net_dim_get_def_rx_moderation);

struct dim_cq_moder
net_dim_get_tx_moderation(u8 cq_period_mode, int ix)
{
	struct dim_cq_moder cq_moder = tx_profile[cq_period_mode][ix];

	cq_moder.cq_period_mode = cq_period_mode;
	return cq_moder;
}
EXPORT_SYMBOL(net_dim_get_tx_moderation);

struct dim_cq_moder
net_dim_get_def_tx_moderation(u8 cq_period_mode)
{
	u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
			NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;

	return net_dim_get_tx_moderation(cq_period_mode, profile_ix);
}
EXPORT_SYMBOL(net_dim_get_def_tx_moderation);

static int net_dim_step(struct dim *dim)
{
	if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
		return DIM_TOO_TIRED;

	switch (dim->tune_state) {
	case DIM_PARKING_ON_TOP:
	case DIM_PARKING_TIRED:
		break;
	case DIM_GOING_RIGHT:
		if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1))
			return DIM_ON_EDGE;
		dim->profile_ix++;
		dim->steps_right++;
		break;
	case DIM_GOING_LEFT:
		if (dim->profile_ix == 0)
			return DIM_ON_EDGE;
		dim->profile_ix--;
		dim->steps_left++;
		break;
	}

	dim->tired++;
	return DIM_STEPPED;
}

static void net_dim_exit_parking(struct dim *dim)
{
	dim->tune_state = dim->profile_ix ? DIM_GOING_LEFT : DIM_GOING_RIGHT;
	net_dim_step(dim);
}

static int net_dim_stats_compare(struct dim_stats *curr,
				 struct dim_stats *prev)
{
	if (!prev->bpms)
		return curr->bpms ? DIM_STATS_BETTER : DIM_STATS_SAME;

	if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms))
		return (curr->bpms > prev->bpms) ? DIM_STATS_BETTER :
						   DIM_STATS_WORSE;

	if (!prev->ppms)
		return curr->ppms ? DIM_STATS_BETTER :
				    DIM_STATS_SAME;

	if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms))
		return (curr->ppms > prev->ppms) ? DIM_STATS_BETTER :
						   DIM_STATS_WORSE;

	if (!prev->epms)
		return DIM_STATS_SAME;

	if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms))
		return (curr->epms < prev->epms) ? DIM_STATS_BETTER :
						   DIM_STATS_WORSE;

	return DIM_STATS_SAME;
}

static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim)
{
	int prev_state = dim->tune_state;
	int prev_ix = dim->profile_ix;
	int stats_res;
	int step_res;

	switch (dim->tune_state) {
	case DIM_PARKING_ON_TOP:
		stats_res = net_dim_stats_compare(curr_stats,
						  &dim->prev_stats);
		if (stats_res != DIM_STATS_SAME)
			net_dim_exit_parking(dim);
		break;

	case DIM_PARKING_TIRED:
		dim->tired--;
		if (!dim->tired)
			net_dim_exit_parking(dim);
		break;

	case DIM_GOING_RIGHT:
	case DIM_GOING_LEFT:
		stats_res = net_dim_stats_compare(curr_stats,
						  &dim->prev_stats);
		if (stats_res != DIM_STATS_BETTER)
			dim_turn(dim);

		if (dim_on_top(dim)) {
			dim_park_on_top(dim);
			break;
		}

		step_res = net_dim_step(dim);
		switch (step_res) {
		case DIM_ON_EDGE:
			dim_park_on_top(dim);
			break;
		case DIM_TOO_TIRED:
			dim_park_tired(dim);
			break;
		}

		break;
	}

	if (prev_state != DIM_PARKING_ON_TOP ||
	    dim->tune_state != DIM_PARKING_ON_TOP)
		dim->prev_stats = *curr_stats;

	return dim->profile_ix != prev_ix;
}

void net_dim(struct dim *dim, struct dim_sample end_sample)
{
	struct dim_stats curr_stats;
	u16 nevents;

	switch (dim->state) {
	case DIM_MEASURE_IN_PROGRESS:
		nevents = BIT_GAP(BITS_PER_TYPE(u16),
				  end_sample.event_ctr,
				  dim->start_sample.event_ctr);
		if (nevents < DIM_NEVENTS)
			break;
		dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats);
		if (net_dim_decision(&curr_stats, dim)) {
			dim->state = DIM_APPLY_NEW_PROFILE;
			schedule_work(&dim->work);
			break;
		}
		fallthrough;
	case DIM_START_MEASURE:
		dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr,
				  end_sample.byte_ctr, &dim->start_sample);
		dim->state = DIM_MEASURE_IN_PROGRESS;
		break;
	case DIM_APPLY_NEW_PROFILE:
		break;
	}
}
EXPORT_SYMBOL(net_dim);