Commit | Line | Data |
---|---|---|
833ad6a0 | 1 | /* |
886d51a3 | 2 | * lttng-context-perf-counters.c |
833ad6a0 MD |
3 | * |
4 | * LTTng performance monitoring counters (perf-counters) integration module. | |
5 | * | |
886d51a3 MD |
6 | * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
833ad6a0 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/perf_event.h> | |
26 | #include <linux/list.h> | |
c24a0d71 | 27 | #include <linux/string.h> |
a90917c3 | 28 | #include "lttng-events.h" |
c24a0d71 MD |
29 | #include "wrapper/ringbuffer/frontend_types.h" |
30 | #include "wrapper/vmalloc.h" | |
90f5546c | 31 | #include "wrapper/perf.h" |
a90917c3 | 32 | #include "lttng-tracer.h" |
833ad6a0 | 33 | |
f1676205 MD |
34 | static |
35 | size_t perf_counter_get_size(size_t offset) | |
36 | { | |
37 | size_t size = 0; | |
38 | ||
a90917c3 | 39 | size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); |
f1676205 MD |
40 | size += sizeof(uint64_t); |
41 | return size; | |
42 | } | |
43 | ||
833ad6a0 MD |
44 | static |
45 | void perf_counter_record(struct lttng_ctx_field *field, | |
46 | struct lib_ring_buffer_ctx *ctx, | |
a90917c3 | 47 | struct lttng_channel *chan) |
833ad6a0 MD |
48 | { |
49 | struct perf_event *event; | |
50 | uint64_t value; | |
51 | ||
2001023e | 52 | event = field->u.perf_counter->e[ctx->cpu]; |
0478c519 | 53 | if (likely(event)) { |
7b745a96 MD |
54 | if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) { |
55 | value = 0; | |
56 | } else { | |
57 | event->pmu->read(event); | |
58 | value = local64_read(&event->count); | |
59 | } | |
f91fd73b MD |
60 | } else { |
61 | /* | |
62 | * Perf chooses not to be clever and not to support enabling a | |
63 | * perf counter before the cpu is brought up. Therefore, we need | |
64 | * to support having events coming (e.g. scheduler events) | |
65 | * before the counter is setup. Write an arbitrary 0 in this | |
66 | * case. | |
67 | */ | |
68 | value = 0; | |
69 | } | |
a90917c3 | 70 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); |
833ad6a0 MD |
71 | chan->ops->event_write(ctx, &value, sizeof(value)); |
72 | } | |
73 | ||
90f5546c MD |
74 | #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99)) |
75 | static | |
76 | void overflow_callback(struct perf_event *event, | |
77 | struct perf_sample_data *data, | |
78 | struct pt_regs *regs) | |
79 | { | |
80 | } | |
81 | #else | |
833ad6a0 MD |
82 | static |
83 | void overflow_callback(struct perf_event *event, int nmi, | |
84 | struct perf_sample_data *data, | |
85 | struct pt_regs *regs) | |
86 | { | |
87 | } | |
90f5546c | 88 | #endif |
833ad6a0 | 89 | |
2dccf128 MD |
90 | static |
91 | void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field) | |
92 | { | |
2001023e | 93 | struct perf_event **events = field->u.perf_counter->e; |
2dccf128 MD |
94 | int cpu; |
95 | ||
8289661d | 96 | get_online_cpus(); |
2dccf128 MD |
97 | for_each_online_cpu(cpu) |
98 | perf_event_release_kernel(events[cpu]); | |
8289661d MD |
99 | put_online_cpus(); |
100 | #ifdef CONFIG_HOTPLUG_CPU | |
2001023e | 101 | unregister_cpu_notifier(&field->u.perf_counter->nb); |
8289661d | 102 | #endif |
c24a0d71 | 103 | kfree(field->event_field.name); |
2001023e | 104 | kfree(field->u.perf_counter->attr); |
2dccf128 | 105 | kfree(events); |
2001023e | 106 | kfree(field->u.perf_counter); |
2dccf128 MD |
107 | } |
108 | ||
8289661d MD |
109 | #ifdef CONFIG_HOTPLUG_CPU |
110 | ||
111 | /** | |
112 | * lttng_perf_counter_hp_callback - CPU hotplug callback | |
113 | * @nb: notifier block | |
114 | * @action: hotplug action to take | |
115 | * @hcpu: CPU number | |
116 | * | |
117 | * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD) | |
118 | * | |
119 | * We can setup perf counters when the cpu is online (up prepare seems to be too | |
120 | * soon). | |
121 | */ | |
122 | static | |
e8f071d5 | 123 | int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb, |
8289661d MD |
124 | unsigned long action, |
125 | void *hcpu) | |
126 | { | |
127 | unsigned int cpu = (unsigned long) hcpu; | |
2001023e MD |
128 | struct lttng_perf_counter_field *perf_field = |
129 | container_of(nb, struct lttng_perf_counter_field, nb); | |
130 | struct perf_event **events = perf_field->e; | |
131 | struct perf_event_attr *attr = perf_field->attr; | |
f91fd73b | 132 | struct perf_event *pevent; |
8289661d | 133 | |
2001023e | 134 | if (!perf_field->hp_enable) |
8289661d MD |
135 | return NOTIFY_OK; |
136 | ||
137 | switch (action) { | |
138 | case CPU_ONLINE: | |
139 | case CPU_ONLINE_FROZEN: | |
90f5546c | 140 | pevent = wrapper_perf_event_create_kernel_counter(attr, |
8289661d | 141 | cpu, NULL, overflow_callback); |
0478c519 | 142 | if (!pevent || IS_ERR(pevent)) |
8289661d | 143 | return NOTIFY_BAD; |
7b745a96 MD |
144 | if (pevent->state == PERF_EVENT_STATE_ERROR) { |
145 | perf_event_release_kernel(pevent); | |
146 | return NOTIFY_BAD; | |
147 | } | |
f91fd73b MD |
148 | barrier(); /* Create perf counter before setting event */ |
149 | events[cpu] = pevent; | |
8289661d MD |
150 | break; |
151 | case CPU_UP_CANCELED: | |
152 | case CPU_UP_CANCELED_FROZEN: | |
153 | case CPU_DEAD: | |
154 | case CPU_DEAD_FROZEN: | |
f91fd73b MD |
155 | pevent = events[cpu]; |
156 | events[cpu] = NULL; | |
157 | barrier(); /* NULLify event before perf counter teardown */ | |
158 | perf_event_release_kernel(pevent); | |
8289661d MD |
159 | break; |
160 | } | |
161 | return NOTIFY_OK; | |
162 | } | |
163 | ||
164 | #endif | |
165 | ||
833ad6a0 MD |
166 | int lttng_add_perf_counter_to_ctx(uint32_t type, |
167 | uint64_t config, | |
c24a0d71 | 168 | const char *name, |
2dccf128 | 169 | struct lttng_ctx **ctx) |
833ad6a0 MD |
170 | { |
171 | struct lttng_ctx_field *field; | |
2001023e | 172 | struct lttng_perf_counter_field *perf_field; |
833ad6a0 MD |
173 | struct perf_event **events; |
174 | struct perf_event_attr *attr; | |
175 | int ret; | |
176 | int cpu; | |
c24a0d71 | 177 | char *name_alloc; |
833ad6a0 MD |
178 | |
179 | events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL); | |
180 | if (!events) | |
181 | return -ENOMEM; | |
182 | ||
2001023e | 183 | attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL); |
833ad6a0 MD |
184 | if (!attr) { |
185 | ret = -ENOMEM; | |
186 | goto error_attr; | |
187 | } | |
188 | ||
189 | attr->type = type; | |
190 | attr->config = config; | |
191 | attr->size = sizeof(struct perf_event_attr); | |
192 | attr->pinned = 1; | |
193 | attr->disabled = 0; | |
194 | ||
2001023e MD |
195 | perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL); |
196 | if (!perf_field) { | |
197 | ret = -ENOMEM; | |
198 | goto error_alloc_perf_field; | |
199 | } | |
200 | perf_field->e = events; | |
201 | perf_field->attr = attr; | |
202 | ||
c24a0d71 | 203 | name_alloc = kstrdup(name, GFP_KERNEL); |
bef96e48 MD |
204 | if (!name_alloc) { |
205 | ret = -ENOMEM; | |
c24a0d71 | 206 | goto name_alloc_error; |
bef96e48 | 207 | } |
c24a0d71 | 208 | |
2dccf128 MD |
209 | field = lttng_append_context(ctx); |
210 | if (!field) { | |
211 | ret = -ENOMEM; | |
8289661d | 212 | goto append_context_error; |
833ad6a0 | 213 | } |
2001023e | 214 | if (lttng_find_context(*ctx, name_alloc)) { |
44252f0f MD |
215 | ret = -EEXIST; |
216 | goto find_error; | |
217 | } | |
8289661d MD |
218 | |
219 | #ifdef CONFIG_HOTPLUG_CPU | |
2001023e | 220 | perf_field->nb.notifier_call = |
8289661d | 221 | lttng_perf_counter_cpu_hp_callback; |
2001023e MD |
222 | perf_field->nb.priority = 0; |
223 | register_cpu_notifier(&perf_field->nb); | |
8289661d MD |
224 | #endif |
225 | ||
226 | get_online_cpus(); | |
227 | for_each_online_cpu(cpu) { | |
90f5546c | 228 | events[cpu] = wrapper_perf_event_create_kernel_counter(attr, |
8289661d | 229 | cpu, NULL, overflow_callback); |
0478c519 | 230 | if (!events[cpu] || IS_ERR(events[cpu])) { |
8289661d MD |
231 | ret = -EINVAL; |
232 | goto counter_error; | |
233 | } | |
7b745a96 MD |
234 | if (events[cpu]->state == PERF_EVENT_STATE_ERROR) { |
235 | ret = -EBUSY; | |
236 | goto counter_busy; | |
237 | } | |
8289661d MD |
238 | } |
239 | put_online_cpus(); | |
240 | ||
2dccf128 | 241 | field->destroy = lttng_destroy_perf_counter_field; |
833ad6a0 | 242 | |
c24a0d71 | 243 | field->event_field.name = name_alloc; |
8070f5c0 | 244 | field->event_field.type.atype = atype_integer; |
9d7d747f | 245 | field->event_field.type.u.basic.integer.size = sizeof(uint64_t) * CHAR_BIT; |
a90917c3 | 246 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT; |
06254b0f | 247 | field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uint64_t); |
8070f5c0 MD |
248 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; |
249 | field->event_field.type.u.basic.integer.base = 10; | |
250 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
f1676205 MD |
251 | field->get_size = perf_counter_get_size; |
252 | field->record = perf_counter_record; | |
2001023e MD |
253 | field->u.perf_counter = perf_field; |
254 | perf_field->hp_enable = 1; | |
833ad6a0 MD |
255 | |
256 | wrapper_vmalloc_sync_all(); | |
257 | return 0; | |
258 | ||
7b745a96 | 259 | counter_busy: |
8289661d | 260 | counter_error: |
833ad6a0 | 261 | for_each_online_cpu(cpu) { |
0478c519 | 262 | if (events[cpu] && !IS_ERR(events[cpu])) |
833ad6a0 MD |
263 | perf_event_release_kernel(events[cpu]); |
264 | } | |
8289661d MD |
265 | put_online_cpus(); |
266 | #ifdef CONFIG_HOTPLUG_CPU | |
2001023e | 267 | unregister_cpu_notifier(&perf_field->nb); |
8289661d | 268 | #endif |
44252f0f | 269 | find_error: |
8289661d MD |
270 | lttng_remove_context_field(ctx, field); |
271 | append_context_error: | |
272 | kfree(name_alloc); | |
273 | name_alloc_error: | |
2001023e MD |
274 | kfree(perf_field); |
275 | error_alloc_perf_field: | |
833ad6a0 MD |
276 | kfree(attr); |
277 | error_attr: | |
278 | kfree(events); | |
279 | return ret; | |
280 | } | |
281 | ||
833ad6a0 MD |
282 | MODULE_LICENSE("GPL and additional rights"); |
283 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
284 | MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support"); |