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
|
/*
* Copyright (c) 2014-2018 Remy Noel.
* Copyright (c) 2014-2018 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* Performance monitoring based on hardware performance counters.
*
* The hardware layer is represented by a performance monitoring unit (PMU),
* which provides performance monitoring counters (PMCs).
*/
#ifndef KERN_PERFMON_H
#define KERN_PERFMON_H
#include <stdint.h>
#include <kern/init.h>
#include <kern/perfmon_types.h>
#include <kern/thread.h>
/*
* IDs of generic performance monitoring events.
*/
#define PERFMON_EV_CYCLE 0
#define PERFMON_EV_REF_CYCLE 1
#define PERFMON_EV_INSTRUCTION 2
#define PERFMON_EV_CACHE_REF 3
#define PERFMON_EV_CACHE_MISS 4
#define PERFMON_EV_BRANCH 5
#define PERFMON_EV_BRANCH_MISS 6
#define PERFMON_NR_GENERIC_EVENTS 7
/*
* Event flags.
*/
#define PERFMON_EF_KERN 0x1 /* Monitor events in kernel mode */
#define PERFMON_EF_USER 0x2 /* Monitor events in user mode */
#define PERFMON_EF_RAW 0x4 /* Raw event ID, generic if unset */
/*
* Performance monitoring operations.
*
* This is a public structure.
*
* All operations are either global but serialized by the caller, or
* processor-local and called with interrupts and preemption disabled.
*
* If the hardware doesn't efficiently support overflow interrupts, the
* handler must be set to NULL, making the perfmon module perdiocally
* check the raw value of the hardware counters.
*/
struct perfmon_dev_ops {
/*
* Convert a generic event ID into a raw event ID.
*
* Global operation.
*/
int (*translate)(unsigned int *raw_event_idp, unsigned int event_id);
/*
* Allocate a performance monitoring counter globally for the given
* raw event ID, and return the counter ID through the given pointer.
* The driver may return any PMC ID, as long as it uniquely identifies
* the underlying counter. The PMC index is passed when reporting
* overflows, if using a custom overflow interrupt handler.
*
* Global operation.
*/
int (*alloc)(unsigned int *pmc_idp, unsigned int pmc_index,
unsigned int raw_event_id);
/*
* Free an allocated performance monitoring counter.
*
* Global operation.
*/
void (*free)(unsigned int pmc_id);
/*
* Start a performance monitoring counter for the given raw event ID.
*
* Processor-local operation.
*/
void (*start)(unsigned int pmc_id, unsigned int raw_event_id);
/*
* Stop a performance monitoring counter.
*
* Processor-local operation.
*/
void (*stop)(unsigned int pmc_id);
/*
* Read the value of a performance monitoring counter.
*
* Processor-local operation.
*/
uint64_t (*read)(unsigned int pmc_id);
/*
* Custom overflow interrupt handler.
*
* Processor-local operation.
*/
void (*handle_overflow_intr)(void);
};
/*
* Performance monitoring device.
*
* This is a public structure.
*
* The PMC width is expressed in bits.
*
* If the driver doesn't provide an overflow interrupt handler, it may set
* the poll interval, in ticks, to a duration that safely allows the detection
* of a single overflow. A value of 0 lets the perfmon module compute a poll
* interval itself.
*/
struct perfmon_dev {
const struct perfmon_dev_ops *ops;
unsigned int pmc_width;
uint64_t poll_interval;
};
/*
* Performance monitoring thread data.
*/
struct perfmon_td;
/*
* Performance monitoring event.
*
* An event describes a single, well-defined hardware condition and tracks
* its occurrences over a period of time.
*/
struct perfmon_event;
/*
* Initialize thread-specific data.
*/
void perfmon_td_init(struct perfmon_td *td);
/*
* Load/unload events attached to a thread on the current processor.
*
* These functions should only be used by the scheduler on a context switch.
* Interrupts and preemption must be disabled when calling these functions.
*/
void perfmon_td_load(struct perfmon_td *td);
void perfmon_td_unload(struct perfmon_td *td);
/*
* Initialize an event.
*/
int perfmon_event_init(struct perfmon_event *event, unsigned int id,
unsigned int flags);
/*
* Attach/detach an event to/from a thread or a processor.
*
* Attaching an event allocates hardware resources and enables monitoring.
* The number of occurrences for the given event is reset.
*
* An event can only be attached to one thread or processor at a time.
*/
int perfmon_event_attach(struct perfmon_event *event, struct thread *thread);
int perfmon_event_attach_cpu(struct perfmon_event *event, unsigned int cpu);
int perfmon_event_detach(struct perfmon_event *event);
/*
* Obtain the number of occurrences of an event.
*/
uint64_t perfmon_event_read(struct perfmon_event *event);
/*
* Register a PMU device.
*
* Currently, there can only be a single system-wide PMU device, which
* assumes the driver is the same for all processors.
*/
void perfmon_register(struct perfmon_dev *dev);
/*
* Handle an overflow interrupt.
*
* This function must be called in interrupt context.
*/
void perfmon_overflow_intr(void);
/*
* Report a PMC overflow.
*
* This function is intended to be used by PMU drivers using a custom
* overflow interrupt handler.
*
* This function must be called in interrupt context.
*/
void perfmon_report_overflow(unsigned int pmc_index);
/*
* This init operation provides :
* - PMU device registration
*/
INIT_OP_DECLARE(perfmon_bootstrap);
#endif /* KERN_PERFMON_H */
|
