Commit | Line | Data |
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d58d1454 MD |
1 | /* |
2 | * lttng-context-perf-counters.c | |
3 | * | |
4 | * LTTng UST performance monitoring counters (perf-counters) integration. | |
5 | * | |
6 | * Copyright (C) 2009-2014 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 | |
21 | */ | |
22 | ||
3fbec7dc | 23 | #define _LGPL_SOURCE |
d58d1454 MD |
24 | #include <sys/types.h> |
25 | #include <unistd.h> | |
26 | #include <string.h> | |
27 | #include <stdlib.h> | |
28 | #include <stdio.h> | |
649fb6b3 | 29 | #include <stdbool.h> |
b4051ad8 | 30 | #include <stddef.h> |
fb31eb73 | 31 | #include <stdint.h> |
d58d1454 MD |
32 | #include <sys/mman.h> |
33 | #include <sys/syscall.h> | |
d58d1454 MD |
34 | #include <lttng/ust-events.h> |
35 | #include <lttng/ust-tracer.h> | |
36 | #include <lttng/ringbuffer-config.h> | |
37 | #include <urcu/system.h> | |
38 | #include <urcu/arch.h> | |
39 | #include <urcu/rculist.h> | |
40 | #include <helper.h> | |
41 | #include <urcu/ref.h> | |
42 | #include <usterr-signal-safe.h> | |
43 | #include <signal.h> | |
20142124 | 44 | #include <urcu/tls-compat.h> |
77d7fa98 | 45 | #include "perf_event.h" |
d58d1454 MD |
46 | #include "lttng-tracer-core.h" |
47 | ||
48 | /* | |
49 | * We use a global perf counter key and iterate on per-thread RCU lists | |
50 | * of fields in the fast path, even though this is not strictly speaking | |
51 | * what would provide the best fast-path complexity, to ensure teardown | |
52 | * of sessions vs thread exit is handled racelessly. | |
53 | * | |
54 | * Updates and traversals of thread_list are protected by UST lock. | |
55 | * Updates to rcu_field_list are protected by UST lock. | |
56 | */ | |
57 | ||
58 | struct lttng_perf_counter_thread_field { | |
59 | struct lttng_perf_counter_field *field; /* Back reference */ | |
60 | struct perf_event_mmap_page *pc; | |
61 | struct cds_list_head thread_field_node; /* Per-field list of thread fields (node) */ | |
62 | struct cds_list_head rcu_field_node; /* RCU per-thread list of fields (node) */ | |
b9389e6e | 63 | int fd; /* Perf FD */ |
d58d1454 MD |
64 | }; |
65 | ||
66 | struct lttng_perf_counter_thread { | |
67 | struct cds_list_head rcu_field_list; /* RCU per-thread list of fields */ | |
68 | }; | |
69 | ||
70 | struct lttng_perf_counter_field { | |
71 | struct perf_event_attr attr; | |
72 | struct cds_list_head thread_field_list; /* Per-field list of thread fields */ | |
73 | }; | |
74 | ||
75 | static pthread_key_t perf_counter_key; | |
76 | ||
20142124 MD |
77 | /* |
78 | * lttng_perf_lock - Protect lttng-ust perf counter data structures | |
79 | * | |
80 | * Nests within the ust_lock, and therefore within the libc dl lock. | |
81 | * Therefore, we need to fixup the TLS before nesting into this lock. | |
82 | * Nests inside RCU bp read-side lock. Protects against concurrent | |
83 | * fork. | |
84 | */ | |
85 | static pthread_mutex_t ust_perf_mutex = PTHREAD_MUTEX_INITIALIZER; | |
86 | ||
87 | /* | |
88 | * Cancel state when grabbing the ust_perf_mutex. Saved when locking, | |
89 | * restored on unlock. Protected by ust_perf_mutex. | |
90 | */ | |
91 | static int ust_perf_saved_cancelstate; | |
92 | ||
93 | /* | |
94 | * Track whether we are tracing from a signal handler nested on an | |
95 | * application thread. | |
96 | */ | |
97 | static DEFINE_URCU_TLS(int, ust_perf_mutex_nest); | |
98 | ||
99 | /* | |
100 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
101 | */ | |
102 | void lttng_ust_fixup_perf_counter_tls(void) | |
103 | { | |
104 | asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest))); | |
105 | } | |
106 | ||
107 | void lttng_perf_lock(void) | |
108 | { | |
109 | sigset_t sig_all_blocked, orig_mask; | |
110 | int ret, oldstate; | |
111 | ||
112 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); | |
113 | if (ret) { | |
114 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
115 | } | |
116 | sigfillset(&sig_all_blocked); | |
117 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
118 | if (ret) { | |
119 | ERR("pthread_sigmask: %s", strerror(ret)); | |
120 | } | |
121 | if (!URCU_TLS(ust_perf_mutex_nest)++) { | |
122 | /* | |
123 | * Ensure the compiler don't move the store after the close() | |
124 | * call in case close() would be marked as leaf. | |
125 | */ | |
126 | cmm_barrier(); | |
127 | pthread_mutex_lock(&ust_perf_mutex); | |
128 | ust_perf_saved_cancelstate = oldstate; | |
129 | } | |
130 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
131 | if (ret) { | |
132 | ERR("pthread_sigmask: %s", strerror(ret)); | |
133 | } | |
134 | } | |
135 | ||
136 | void lttng_perf_unlock(void) | |
137 | { | |
138 | sigset_t sig_all_blocked, orig_mask; | |
139 | int ret, newstate, oldstate; | |
140 | bool restore_cancel = false; | |
141 | ||
142 | sigfillset(&sig_all_blocked); | |
143 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
144 | if (ret) { | |
145 | ERR("pthread_sigmask: %s", strerror(ret)); | |
146 | } | |
147 | /* | |
148 | * Ensure the compiler don't move the store before the close() | |
149 | * call, in case close() would be marked as leaf. | |
150 | */ | |
151 | cmm_barrier(); | |
152 | if (!--URCU_TLS(ust_perf_mutex_nest)) { | |
153 | newstate = ust_perf_saved_cancelstate; | |
154 | restore_cancel = true; | |
155 | pthread_mutex_unlock(&ust_perf_mutex); | |
156 | } | |
157 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
158 | if (ret) { | |
159 | ERR("pthread_sigmask: %s", strerror(ret)); | |
160 | } | |
161 | if (restore_cancel) { | |
162 | ret = pthread_setcancelstate(newstate, &oldstate); | |
163 | if (ret) { | |
164 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
165 | } | |
166 | } | |
167 | } | |
168 | ||
d58d1454 | 169 | static |
53569322 | 170 | size_t perf_counter_get_size(struct lttng_ctx_field *field, size_t offset) |
d58d1454 MD |
171 | { |
172 | size_t size = 0; | |
173 | ||
174 | size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); | |
175 | size += sizeof(uint64_t); | |
176 | return size; | |
177 | } | |
178 | ||
a3a8d943 MD |
179 | static |
180 | uint64_t read_perf_counter_syscall( | |
181 | struct lttng_perf_counter_thread_field *thread_field) | |
182 | { | |
183 | uint64_t count; | |
184 | ||
185 | if (caa_unlikely(thread_field->fd < 0)) | |
186 | return 0; | |
187 | ||
188 | if (caa_unlikely(read(thread_field->fd, &count, sizeof(count)) | |
189 | < sizeof(count))) | |
190 | return 0; | |
191 | ||
192 | return count; | |
193 | } | |
194 | ||
d58d1454 MD |
195 | #if defined(__x86_64__) || defined(__i386__) |
196 | ||
197 | static | |
198 | uint64_t rdpmc(unsigned int counter) | |
199 | { | |
200 | unsigned int low, high; | |
201 | ||
202 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
203 | ||
204 | return low | ((uint64_t) high) << 32; | |
205 | } | |
206 | ||
77d7fa98 MD |
207 | static |
208 | bool has_rdpmc(struct perf_event_mmap_page *pc) | |
209 | { | |
210 | if (caa_unlikely(!pc->cap_bit0_is_deprecated)) | |
211 | return false; | |
212 | /* Since Linux kernel 3.12. */ | |
213 | return pc->cap_user_rdpmc; | |
214 | } | |
215 | ||
d58d1454 | 216 | static |
a3a8d943 | 217 | uint64_t arch_read_perf_counter( |
d286ad50 | 218 | struct lttng_perf_counter_thread_field *thread_field) |
d58d1454 MD |
219 | { |
220 | uint32_t seq, idx; | |
221 | uint64_t count; | |
d286ad50 | 222 | struct perf_event_mmap_page *pc = thread_field->pc; |
d58d1454 MD |
223 | |
224 | if (caa_unlikely(!pc)) | |
225 | return 0; | |
226 | ||
227 | do { | |
228 | seq = CMM_LOAD_SHARED(pc->lock); | |
229 | cmm_barrier(); | |
230 | ||
231 | idx = pc->index; | |
77d7fa98 | 232 | if (caa_likely(has_rdpmc(pc) && idx)) { |
4f58f54f MD |
233 | int64_t pmcval; |
234 | ||
235 | pmcval = rdpmc(idx - 1); | |
236 | /* Sign-extend the pmc register result. */ | |
237 | pmcval <<= 64 - pc->pmc_width; | |
238 | pmcval >>= 64 - pc->pmc_width; | |
239 | count = pc->offset + pmcval; | |
240 | } else { | |
a3a8d943 MD |
241 | /* Fall-back on system call if rdpmc cannot be used. */ |
242 | return read_perf_counter_syscall(thread_field); | |
4f58f54f | 243 | } |
d58d1454 MD |
244 | cmm_barrier(); |
245 | } while (CMM_LOAD_SHARED(pc->lock) != seq); | |
246 | ||
247 | return count; | |
248 | } | |
249 | ||
d286ad50 | 250 | static |
a3a8d943 | 251 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) |
d286ad50 | 252 | { |
a3a8d943 | 253 | struct perf_event_mmap_page *pc = thread_field->pc; |
d286ad50 | 254 | |
a3a8d943 | 255 | if (!pc) |
d286ad50 | 256 | return 0; |
77d7fa98 | 257 | return !has_rdpmc(pc); |
a3a8d943 | 258 | } |
d286ad50 | 259 | |
a3a8d943 | 260 | #else |
d286ad50 | 261 | |
a3a8d943 MD |
262 | /* Generic (slow) implementation using a read system call. */ |
263 | static | |
264 | uint64_t arch_read_perf_counter( | |
265 | struct lttng_perf_counter_thread_field *thread_field) | |
266 | { | |
267 | return read_perf_counter_syscall(thread_field); | |
d286ad50 JD |
268 | } |
269 | ||
a3a8d943 MD |
270 | static |
271 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) | |
272 | { | |
273 | return 1; | |
274 | } | |
d286ad50 | 275 | |
a3a8d943 | 276 | #endif |
d286ad50 | 277 | |
d58d1454 MD |
278 | static |
279 | int sys_perf_event_open(struct perf_event_attr *attr, | |
280 | pid_t pid, int cpu, int group_fd, | |
281 | unsigned long flags) | |
282 | { | |
283 | return syscall(SYS_perf_event_open, attr, pid, cpu, | |
284 | group_fd, flags); | |
285 | } | |
286 | ||
287 | static | |
b9389e6e | 288 | int open_perf_fd(struct perf_event_attr *attr) |
d58d1454 | 289 | { |
b9389e6e | 290 | int fd; |
d58d1454 MD |
291 | |
292 | fd = sys_perf_event_open(attr, 0, -1, -1, 0); | |
293 | if (fd < 0) | |
b9389e6e JD |
294 | return -1; |
295 | ||
296 | return fd; | |
297 | } | |
298 | ||
d286ad50 JD |
299 | static |
300 | void close_perf_fd(int fd) | |
301 | { | |
302 | int ret; | |
303 | ||
304 | if (fd < 0) | |
305 | return; | |
306 | ||
307 | ret = close(fd); | |
308 | if (ret) { | |
309 | perror("Error closing LTTng-UST perf memory mapping FD"); | |
310 | } | |
311 | } | |
312 | ||
77d7fa98 | 313 | static void setup_perf(struct lttng_perf_counter_thread_field *thread_field) |
b9389e6e JD |
314 | { |
315 | void *perf_addr; | |
d58d1454 MD |
316 | |
317 | perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page), | |
b9389e6e | 318 | PROT_READ, MAP_SHARED, thread_field->fd, 0); |
d58d1454 | 319 | if (perf_addr == MAP_FAILED) |
b9389e6e | 320 | perf_addr = NULL; |
77d7fa98 | 321 | thread_field->pc = perf_addr; |
b9389e6e | 322 | |
a3a8d943 | 323 | if (!arch_perf_keep_fd(thread_field)) { |
b9389e6e JD |
324 | close_perf_fd(thread_field->fd); |
325 | thread_field->fd = -1; | |
6c2125af | 326 | } |
d58d1454 MD |
327 | } |
328 | ||
329 | static | |
330 | void unmap_perf_page(struct perf_event_mmap_page *pc) | |
331 | { | |
332 | int ret; | |
333 | ||
334 | if (!pc) | |
335 | return; | |
336 | ret = munmap(pc, sizeof(struct perf_event_mmap_page)); | |
337 | if (ret < 0) { | |
338 | PERROR("Error in munmap"); | |
339 | abort(); | |
340 | } | |
341 | } | |
342 | ||
343 | static | |
344 | struct lttng_perf_counter_thread *alloc_perf_counter_thread(void) | |
345 | { | |
346 | struct lttng_perf_counter_thread *perf_thread; | |
347 | sigset_t newmask, oldmask; | |
348 | int ret; | |
349 | ||
350 | ret = sigfillset(&newmask); | |
351 | if (ret) | |
352 | abort(); | |
353 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
354 | if (ret) | |
355 | abort(); | |
356 | /* Check again with signals disabled */ | |
357 | perf_thread = pthread_getspecific(perf_counter_key); | |
358 | if (perf_thread) | |
359 | goto skip; | |
360 | perf_thread = zmalloc(sizeof(*perf_thread)); | |
361 | if (!perf_thread) | |
362 | abort(); | |
363 | CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list); | |
364 | ret = pthread_setspecific(perf_counter_key, perf_thread); | |
365 | if (ret) | |
366 | abort(); | |
367 | skip: | |
368 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
369 | if (ret) | |
370 | abort(); | |
371 | return perf_thread; | |
372 | } | |
373 | ||
374 | static | |
375 | struct lttng_perf_counter_thread_field * | |
376 | add_thread_field(struct lttng_perf_counter_field *perf_field, | |
377 | struct lttng_perf_counter_thread *perf_thread) | |
378 | { | |
379 | struct lttng_perf_counter_thread_field *thread_field; | |
380 | sigset_t newmask, oldmask; | |
381 | int ret; | |
382 | ||
383 | ret = sigfillset(&newmask); | |
384 | if (ret) | |
385 | abort(); | |
386 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
387 | if (ret) | |
388 | abort(); | |
389 | /* Check again with signals disabled */ | |
390 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
391 | rcu_field_node) { | |
392 | if (thread_field->field == perf_field) | |
393 | goto skip; | |
394 | } | |
395 | thread_field = zmalloc(sizeof(*thread_field)); | |
396 | if (!thread_field) | |
397 | abort(); | |
398 | thread_field->field = perf_field; | |
b9389e6e JD |
399 | thread_field->fd = open_perf_fd(&perf_field->attr); |
400 | if (thread_field->fd >= 0) | |
77d7fa98 | 401 | setup_perf(thread_field); |
b9389e6e JD |
402 | /* |
403 | * Note: thread_field->pc can be NULL if setup_perf() fails. | |
404 | * Also, thread_field->fd can be -1 if open_perf_fd() fails. | |
405 | */ | |
20142124 | 406 | lttng_perf_lock(); |
d58d1454 MD |
407 | cds_list_add_rcu(&thread_field->rcu_field_node, |
408 | &perf_thread->rcu_field_list); | |
409 | cds_list_add(&thread_field->thread_field_node, | |
410 | &perf_field->thread_field_list); | |
20142124 | 411 | lttng_perf_unlock(); |
d58d1454 MD |
412 | skip: |
413 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
414 | if (ret) | |
415 | abort(); | |
416 | return thread_field; | |
417 | } | |
418 | ||
419 | static | |
420 | struct lttng_perf_counter_thread_field * | |
421 | get_thread_field(struct lttng_perf_counter_field *field) | |
422 | { | |
423 | struct lttng_perf_counter_thread *perf_thread; | |
424 | struct lttng_perf_counter_thread_field *thread_field; | |
425 | ||
426 | perf_thread = pthread_getspecific(perf_counter_key); | |
427 | if (!perf_thread) | |
428 | perf_thread = alloc_perf_counter_thread(); | |
429 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
430 | rcu_field_node) { | |
431 | if (thread_field->field == field) | |
432 | return thread_field; | |
433 | } | |
434 | /* perf_counter_thread_field not found, need to add one */ | |
435 | return add_thread_field(field, perf_thread); | |
436 | } | |
437 | ||
438 | static | |
439 | uint64_t wrapper_perf_counter_read(struct lttng_ctx_field *field) | |
440 | { | |
441 | struct lttng_perf_counter_field *perf_field; | |
442 | struct lttng_perf_counter_thread_field *perf_thread_field; | |
443 | ||
444 | perf_field = field->u.perf_counter; | |
445 | perf_thread_field = get_thread_field(perf_field); | |
a3a8d943 | 446 | return arch_read_perf_counter(perf_thread_field); |
d58d1454 MD |
447 | } |
448 | ||
449 | static | |
450 | void perf_counter_record(struct lttng_ctx_field *field, | |
451 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
452 | struct lttng_channel *chan) | |
453 | { | |
454 | uint64_t value; | |
455 | ||
456 | value = wrapper_perf_counter_read(field); | |
457 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); | |
458 | chan->ops->event_write(ctx, &value, sizeof(value)); | |
459 | } | |
460 | ||
461 | static | |
462 | void perf_counter_get_value(struct lttng_ctx_field *field, | |
53569322 | 463 | struct lttng_ctx_value *value) |
d58d1454 | 464 | { |
6e9ac4ae | 465 | value->u.s64 = wrapper_perf_counter_read(field); |
d58d1454 MD |
466 | } |
467 | ||
20142124 | 468 | /* Called with perf lock held */ |
d58d1454 MD |
469 | static |
470 | void lttng_destroy_perf_thread_field( | |
471 | struct lttng_perf_counter_thread_field *thread_field) | |
472 | { | |
b9389e6e | 473 | close_perf_fd(thread_field->fd); |
d58d1454 MD |
474 | unmap_perf_page(thread_field->pc); |
475 | cds_list_del_rcu(&thread_field->rcu_field_node); | |
476 | cds_list_del(&thread_field->thread_field_node); | |
477 | free(thread_field); | |
478 | } | |
479 | ||
480 | static | |
481 | void lttng_destroy_perf_thread_key(void *_key) | |
482 | { | |
483 | struct lttng_perf_counter_thread *perf_thread = _key; | |
484 | struct lttng_perf_counter_thread_field *pos, *p; | |
485 | ||
20142124 | 486 | lttng_perf_lock(); |
d58d1454 MD |
487 | cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list, |
488 | rcu_field_node) | |
489 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 490 | lttng_perf_unlock(); |
d58d1454 MD |
491 | free(perf_thread); |
492 | } | |
493 | ||
494 | /* Called with UST lock held */ | |
495 | static | |
496 | void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field) | |
497 | { | |
498 | struct lttng_perf_counter_field *perf_field; | |
499 | struct lttng_perf_counter_thread_field *pos, *p; | |
500 | ||
501 | free((char *) field->event_field.name); | |
502 | perf_field = field->u.perf_counter; | |
503 | /* | |
504 | * This put is performed when no threads can concurrently | |
505 | * perform a "get" concurrently, thanks to urcu-bp grace | |
20142124 MD |
506 | * period. Holding the lttng perf lock protects against |
507 | * concurrent modification of the per-thread thread field | |
508 | * list. | |
d58d1454 | 509 | */ |
20142124 | 510 | lttng_perf_lock(); |
d58d1454 MD |
511 | cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list, |
512 | thread_field_node) | |
513 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 514 | lttng_perf_unlock(); |
d58d1454 MD |
515 | free(perf_field); |
516 | } | |
517 | ||
d286ad50 JD |
518 | #ifdef __ARM_ARCH_7A__ |
519 | ||
520 | static | |
521 | int perf_get_exclude_kernel(void) | |
522 | { | |
523 | return 0; | |
524 | } | |
525 | ||
526 | #else /* __ARM_ARCH_7A__ */ | |
527 | ||
528 | static | |
529 | int perf_get_exclude_kernel(void) | |
530 | { | |
531 | return 1; | |
532 | } | |
533 | ||
534 | #endif /* __ARM_ARCH_7A__ */ | |
535 | ||
d58d1454 MD |
536 | /* Called with UST lock held */ |
537 | int lttng_add_perf_counter_to_ctx(uint32_t type, | |
538 | uint64_t config, | |
539 | const char *name, | |
540 | struct lttng_ctx **ctx) | |
541 | { | |
542 | struct lttng_ctx_field *field; | |
543 | struct lttng_perf_counter_field *perf_field; | |
d58d1454 MD |
544 | char *name_alloc; |
545 | int ret; | |
546 | ||
547 | name_alloc = strdup(name); | |
548 | if (!name_alloc) { | |
549 | ret = -ENOMEM; | |
550 | goto name_alloc_error; | |
551 | } | |
552 | perf_field = zmalloc(sizeof(*perf_field)); | |
553 | if (!perf_field) { | |
554 | ret = -ENOMEM; | |
555 | goto perf_field_alloc_error; | |
556 | } | |
557 | field = lttng_append_context(ctx); | |
558 | if (!field) { | |
559 | ret = -ENOMEM; | |
560 | goto append_context_error; | |
561 | } | |
562 | if (lttng_find_context(*ctx, name_alloc)) { | |
563 | ret = -EEXIST; | |
564 | goto find_error; | |
565 | } | |
566 | ||
567 | field->destroy = lttng_destroy_perf_counter_field; | |
568 | ||
569 | field->event_field.name = name_alloc; | |
570 | field->event_field.type.atype = atype_integer; | |
218deb69 | 571 | field->event_field.type.u.integer.size = |
d58d1454 | 572 | sizeof(uint64_t) * CHAR_BIT; |
218deb69 | 573 | field->event_field.type.u.integer.alignment = |
d58d1454 | 574 | lttng_alignof(uint64_t) * CHAR_BIT; |
218deb69 | 575 | field->event_field.type.u.integer.signedness = |
d58d1454 | 576 | lttng_is_signed_type(uint64_t); |
218deb69 MD |
577 | field->event_field.type.u.integer.reverse_byte_order = 0; |
578 | field->event_field.type.u.integer.base = 10; | |
579 | field->event_field.type.u.integer.encoding = lttng_encode_none; | |
d58d1454 MD |
580 | field->get_size = perf_counter_get_size; |
581 | field->record = perf_counter_record; | |
582 | field->get_value = perf_counter_get_value; | |
583 | ||
584 | perf_field->attr.type = type; | |
585 | perf_field->attr.config = config; | |
d286ad50 | 586 | perf_field->attr.exclude_kernel = perf_get_exclude_kernel(); |
d58d1454 MD |
587 | CDS_INIT_LIST_HEAD(&perf_field->thread_field_list); |
588 | field->u.perf_counter = perf_field; | |
589 | ||
590 | /* Ensure that this perf counter can be used in this process. */ | |
b9389e6e JD |
591 | ret = open_perf_fd(&perf_field->attr); |
592 | if (ret < 0) { | |
d58d1454 MD |
593 | ret = -ENODEV; |
594 | goto setup_error; | |
595 | } | |
b9389e6e | 596 | close_perf_fd(ret); |
d58d1454 MD |
597 | |
598 | /* | |
599 | * Contexts can only be added before tracing is started, so we | |
600 | * don't have to synchronize against concurrent threads using | |
601 | * the field here. | |
602 | */ | |
603 | ||
b2cc986a | 604 | lttng_context_update(*ctx); |
d58d1454 MD |
605 | return 0; |
606 | ||
607 | setup_error: | |
608 | find_error: | |
609 | lttng_remove_context_field(ctx, field); | |
610 | append_context_error: | |
611 | free(perf_field); | |
612 | perf_field_alloc_error: | |
613 | free(name_alloc); | |
614 | name_alloc_error: | |
615 | return ret; | |
616 | } | |
617 | ||
618 | int lttng_perf_counter_init(void) | |
619 | { | |
620 | int ret; | |
621 | ||
622 | ret = pthread_key_create(&perf_counter_key, | |
623 | lttng_destroy_perf_thread_key); | |
624 | if (ret) | |
625 | ret = -ret; | |
626 | return ret; | |
627 | } | |
628 | ||
629 | void lttng_perf_counter_exit(void) | |
630 | { | |
631 | int ret; | |
632 | ||
633 | ret = pthread_key_delete(perf_counter_key); | |
634 | if (ret) { | |
635 | errno = ret; | |
636 | PERROR("Error in pthread_key_delete"); | |
637 | } | |
638 | } |