Commit | Line | Data |
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d58d1454 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
d58d1454 MD |
3 | * |
4 | * Copyright (C) 2009-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
c0c0989a | 6 | * LTTng UST performance monitoring counters (perf-counters) integration. |
d58d1454 MD |
7 | */ |
8 | ||
3fbec7dc | 9 | #define _LGPL_SOURCE |
d58d1454 MD |
10 | #include <sys/types.h> |
11 | #include <unistd.h> | |
12 | #include <string.h> | |
13 | #include <stdlib.h> | |
14 | #include <stdio.h> | |
649fb6b3 | 15 | #include <stdbool.h> |
b4051ad8 | 16 | #include <stddef.h> |
fb31eb73 | 17 | #include <stdint.h> |
d58d1454 MD |
18 | #include <sys/mman.h> |
19 | #include <sys/syscall.h> | |
d58d1454 MD |
20 | #include <lttng/ust-events.h> |
21 | #include <lttng/ust-tracer.h> | |
22 | #include <lttng/ringbuffer-config.h> | |
23 | #include <urcu/system.h> | |
24 | #include <urcu/arch.h> | |
25 | #include <urcu/rculist.h> | |
26 | #include <helper.h> | |
27 | #include <urcu/ref.h> | |
28 | #include <usterr-signal-safe.h> | |
29 | #include <signal.h> | |
20142124 | 30 | #include <urcu/tls-compat.h> |
77d7fa98 | 31 | #include "perf_event.h" |
d58d1454 MD |
32 | #include "lttng-tracer-core.h" |
33 | ||
34 | /* | |
35 | * We use a global perf counter key and iterate on per-thread RCU lists | |
36 | * of fields in the fast path, even though this is not strictly speaking | |
37 | * what would provide the best fast-path complexity, to ensure teardown | |
38 | * of sessions vs thread exit is handled racelessly. | |
39 | * | |
40 | * Updates and traversals of thread_list are protected by UST lock. | |
41 | * Updates to rcu_field_list are protected by UST lock. | |
42 | */ | |
43 | ||
44 | struct lttng_perf_counter_thread_field { | |
45 | struct lttng_perf_counter_field *field; /* Back reference */ | |
46 | struct perf_event_mmap_page *pc; | |
47 | struct cds_list_head thread_field_node; /* Per-field list of thread fields (node) */ | |
48 | struct cds_list_head rcu_field_node; /* RCU per-thread list of fields (node) */ | |
b9389e6e | 49 | int fd; /* Perf FD */ |
d58d1454 MD |
50 | }; |
51 | ||
52 | struct lttng_perf_counter_thread { | |
53 | struct cds_list_head rcu_field_list; /* RCU per-thread list of fields */ | |
54 | }; | |
55 | ||
56 | struct lttng_perf_counter_field { | |
57 | struct perf_event_attr attr; | |
58 | struct cds_list_head thread_field_list; /* Per-field list of thread fields */ | |
59 | }; | |
60 | ||
61 | static pthread_key_t perf_counter_key; | |
62 | ||
20142124 MD |
63 | /* |
64 | * lttng_perf_lock - Protect lttng-ust perf counter data structures | |
65 | * | |
66 | * Nests within the ust_lock, and therefore within the libc dl lock. | |
67 | * Therefore, we need to fixup the TLS before nesting into this lock. | |
68 | * Nests inside RCU bp read-side lock. Protects against concurrent | |
69 | * fork. | |
70 | */ | |
71 | static pthread_mutex_t ust_perf_mutex = PTHREAD_MUTEX_INITIALIZER; | |
72 | ||
73 | /* | |
74 | * Cancel state when grabbing the ust_perf_mutex. Saved when locking, | |
75 | * restored on unlock. Protected by ust_perf_mutex. | |
76 | */ | |
77 | static int ust_perf_saved_cancelstate; | |
78 | ||
79 | /* | |
80 | * Track whether we are tracing from a signal handler nested on an | |
81 | * application thread. | |
82 | */ | |
83 | static DEFINE_URCU_TLS(int, ust_perf_mutex_nest); | |
84 | ||
85 | /* | |
86 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
87 | */ | |
88 | void lttng_ust_fixup_perf_counter_tls(void) | |
89 | { | |
90 | asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest))); | |
91 | } | |
92 | ||
93 | void lttng_perf_lock(void) | |
94 | { | |
95 | sigset_t sig_all_blocked, orig_mask; | |
96 | int ret, oldstate; | |
97 | ||
98 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); | |
99 | if (ret) { | |
100 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
101 | } | |
102 | sigfillset(&sig_all_blocked); | |
103 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
104 | if (ret) { | |
105 | ERR("pthread_sigmask: %s", strerror(ret)); | |
106 | } | |
107 | if (!URCU_TLS(ust_perf_mutex_nest)++) { | |
108 | /* | |
109 | * Ensure the compiler don't move the store after the close() | |
110 | * call in case close() would be marked as leaf. | |
111 | */ | |
112 | cmm_barrier(); | |
113 | pthread_mutex_lock(&ust_perf_mutex); | |
114 | ust_perf_saved_cancelstate = oldstate; | |
115 | } | |
116 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
117 | if (ret) { | |
118 | ERR("pthread_sigmask: %s", strerror(ret)); | |
119 | } | |
120 | } | |
121 | ||
122 | void lttng_perf_unlock(void) | |
123 | { | |
124 | sigset_t sig_all_blocked, orig_mask; | |
125 | int ret, newstate, oldstate; | |
126 | bool restore_cancel = false; | |
127 | ||
128 | sigfillset(&sig_all_blocked); | |
129 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
130 | if (ret) { | |
131 | ERR("pthread_sigmask: %s", strerror(ret)); | |
132 | } | |
133 | /* | |
134 | * Ensure the compiler don't move the store before the close() | |
135 | * call, in case close() would be marked as leaf. | |
136 | */ | |
137 | cmm_barrier(); | |
138 | if (!--URCU_TLS(ust_perf_mutex_nest)) { | |
139 | newstate = ust_perf_saved_cancelstate; | |
140 | restore_cancel = true; | |
141 | pthread_mutex_unlock(&ust_perf_mutex); | |
142 | } | |
143 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
144 | if (ret) { | |
145 | ERR("pthread_sigmask: %s", strerror(ret)); | |
146 | } | |
147 | if (restore_cancel) { | |
148 | ret = pthread_setcancelstate(newstate, &oldstate); | |
149 | if (ret) { | |
150 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
151 | } | |
152 | } | |
153 | } | |
154 | ||
d58d1454 | 155 | static |
53569322 | 156 | size_t perf_counter_get_size(struct lttng_ctx_field *field, size_t offset) |
d58d1454 MD |
157 | { |
158 | size_t size = 0; | |
159 | ||
160 | size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); | |
161 | size += sizeof(uint64_t); | |
162 | return size; | |
163 | } | |
164 | ||
a3a8d943 MD |
165 | static |
166 | uint64_t read_perf_counter_syscall( | |
167 | struct lttng_perf_counter_thread_field *thread_field) | |
168 | { | |
169 | uint64_t count; | |
170 | ||
171 | if (caa_unlikely(thread_field->fd < 0)) | |
172 | return 0; | |
173 | ||
174 | if (caa_unlikely(read(thread_field->fd, &count, sizeof(count)) | |
175 | < sizeof(count))) | |
176 | return 0; | |
177 | ||
178 | return count; | |
179 | } | |
180 | ||
d58d1454 MD |
181 | #if defined(__x86_64__) || defined(__i386__) |
182 | ||
183 | static | |
184 | uint64_t rdpmc(unsigned int counter) | |
185 | { | |
186 | unsigned int low, high; | |
187 | ||
188 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
189 | ||
190 | return low | ((uint64_t) high) << 32; | |
191 | } | |
192 | ||
77d7fa98 MD |
193 | static |
194 | bool has_rdpmc(struct perf_event_mmap_page *pc) | |
195 | { | |
196 | if (caa_unlikely(!pc->cap_bit0_is_deprecated)) | |
197 | return false; | |
198 | /* Since Linux kernel 3.12. */ | |
199 | return pc->cap_user_rdpmc; | |
200 | } | |
201 | ||
d58d1454 | 202 | static |
a3a8d943 | 203 | uint64_t arch_read_perf_counter( |
d286ad50 | 204 | struct lttng_perf_counter_thread_field *thread_field) |
d58d1454 MD |
205 | { |
206 | uint32_t seq, idx; | |
207 | uint64_t count; | |
d286ad50 | 208 | struct perf_event_mmap_page *pc = thread_field->pc; |
d58d1454 MD |
209 | |
210 | if (caa_unlikely(!pc)) | |
211 | return 0; | |
212 | ||
213 | do { | |
214 | seq = CMM_LOAD_SHARED(pc->lock); | |
215 | cmm_barrier(); | |
216 | ||
217 | idx = pc->index; | |
77d7fa98 | 218 | if (caa_likely(has_rdpmc(pc) && idx)) { |
4f58f54f MD |
219 | int64_t pmcval; |
220 | ||
221 | pmcval = rdpmc(idx - 1); | |
222 | /* Sign-extend the pmc register result. */ | |
223 | pmcval <<= 64 - pc->pmc_width; | |
224 | pmcval >>= 64 - pc->pmc_width; | |
225 | count = pc->offset + pmcval; | |
226 | } else { | |
a3a8d943 MD |
227 | /* Fall-back on system call if rdpmc cannot be used. */ |
228 | return read_perf_counter_syscall(thread_field); | |
4f58f54f | 229 | } |
d58d1454 MD |
230 | cmm_barrier(); |
231 | } while (CMM_LOAD_SHARED(pc->lock) != seq); | |
232 | ||
233 | return count; | |
234 | } | |
235 | ||
d286ad50 | 236 | static |
a3a8d943 | 237 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) |
d286ad50 | 238 | { |
a3a8d943 | 239 | struct perf_event_mmap_page *pc = thread_field->pc; |
d286ad50 | 240 | |
a3a8d943 | 241 | if (!pc) |
d286ad50 | 242 | return 0; |
77d7fa98 | 243 | return !has_rdpmc(pc); |
a3a8d943 | 244 | } |
d286ad50 | 245 | |
a3a8d943 | 246 | #else |
d286ad50 | 247 | |
a3a8d943 MD |
248 | /* Generic (slow) implementation using a read system call. */ |
249 | static | |
250 | uint64_t arch_read_perf_counter( | |
251 | struct lttng_perf_counter_thread_field *thread_field) | |
252 | { | |
253 | return read_perf_counter_syscall(thread_field); | |
d286ad50 JD |
254 | } |
255 | ||
a3a8d943 MD |
256 | static |
257 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) | |
258 | { | |
259 | return 1; | |
260 | } | |
d286ad50 | 261 | |
a3a8d943 | 262 | #endif |
d286ad50 | 263 | |
d58d1454 MD |
264 | static |
265 | int sys_perf_event_open(struct perf_event_attr *attr, | |
266 | pid_t pid, int cpu, int group_fd, | |
267 | unsigned long flags) | |
268 | { | |
269 | return syscall(SYS_perf_event_open, attr, pid, cpu, | |
270 | group_fd, flags); | |
271 | } | |
272 | ||
273 | static | |
b9389e6e | 274 | int open_perf_fd(struct perf_event_attr *attr) |
d58d1454 | 275 | { |
b9389e6e | 276 | int fd; |
d58d1454 MD |
277 | |
278 | fd = sys_perf_event_open(attr, 0, -1, -1, 0); | |
279 | if (fd < 0) | |
b9389e6e JD |
280 | return -1; |
281 | ||
282 | return fd; | |
283 | } | |
284 | ||
d286ad50 JD |
285 | static |
286 | void close_perf_fd(int fd) | |
287 | { | |
288 | int ret; | |
289 | ||
290 | if (fd < 0) | |
291 | return; | |
292 | ||
293 | ret = close(fd); | |
294 | if (ret) { | |
295 | perror("Error closing LTTng-UST perf memory mapping FD"); | |
296 | } | |
297 | } | |
298 | ||
77d7fa98 | 299 | static void setup_perf(struct lttng_perf_counter_thread_field *thread_field) |
b9389e6e JD |
300 | { |
301 | void *perf_addr; | |
d58d1454 MD |
302 | |
303 | perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page), | |
b9389e6e | 304 | PROT_READ, MAP_SHARED, thread_field->fd, 0); |
d58d1454 | 305 | if (perf_addr == MAP_FAILED) |
b9389e6e | 306 | perf_addr = NULL; |
77d7fa98 | 307 | thread_field->pc = perf_addr; |
b9389e6e | 308 | |
a3a8d943 | 309 | if (!arch_perf_keep_fd(thread_field)) { |
b9389e6e JD |
310 | close_perf_fd(thread_field->fd); |
311 | thread_field->fd = -1; | |
6c2125af | 312 | } |
d58d1454 MD |
313 | } |
314 | ||
315 | static | |
316 | void unmap_perf_page(struct perf_event_mmap_page *pc) | |
317 | { | |
318 | int ret; | |
319 | ||
320 | if (!pc) | |
321 | return; | |
322 | ret = munmap(pc, sizeof(struct perf_event_mmap_page)); | |
323 | if (ret < 0) { | |
324 | PERROR("Error in munmap"); | |
325 | abort(); | |
326 | } | |
327 | } | |
328 | ||
329 | static | |
330 | struct lttng_perf_counter_thread *alloc_perf_counter_thread(void) | |
331 | { | |
332 | struct lttng_perf_counter_thread *perf_thread; | |
333 | sigset_t newmask, oldmask; | |
334 | int ret; | |
335 | ||
336 | ret = sigfillset(&newmask); | |
337 | if (ret) | |
338 | abort(); | |
339 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
340 | if (ret) | |
341 | abort(); | |
342 | /* Check again with signals disabled */ | |
343 | perf_thread = pthread_getspecific(perf_counter_key); | |
344 | if (perf_thread) | |
345 | goto skip; | |
346 | perf_thread = zmalloc(sizeof(*perf_thread)); | |
347 | if (!perf_thread) | |
348 | abort(); | |
349 | CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list); | |
350 | ret = pthread_setspecific(perf_counter_key, perf_thread); | |
351 | if (ret) | |
352 | abort(); | |
353 | skip: | |
354 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
355 | if (ret) | |
356 | abort(); | |
357 | return perf_thread; | |
358 | } | |
359 | ||
360 | static | |
361 | struct lttng_perf_counter_thread_field * | |
362 | add_thread_field(struct lttng_perf_counter_field *perf_field, | |
363 | struct lttng_perf_counter_thread *perf_thread) | |
364 | { | |
365 | struct lttng_perf_counter_thread_field *thread_field; | |
366 | sigset_t newmask, oldmask; | |
367 | int ret; | |
368 | ||
369 | ret = sigfillset(&newmask); | |
370 | if (ret) | |
371 | abort(); | |
372 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
373 | if (ret) | |
374 | abort(); | |
375 | /* Check again with signals disabled */ | |
376 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
377 | rcu_field_node) { | |
378 | if (thread_field->field == perf_field) | |
379 | goto skip; | |
380 | } | |
381 | thread_field = zmalloc(sizeof(*thread_field)); | |
382 | if (!thread_field) | |
383 | abort(); | |
384 | thread_field->field = perf_field; | |
b9389e6e JD |
385 | thread_field->fd = open_perf_fd(&perf_field->attr); |
386 | if (thread_field->fd >= 0) | |
77d7fa98 | 387 | setup_perf(thread_field); |
b9389e6e JD |
388 | /* |
389 | * Note: thread_field->pc can be NULL if setup_perf() fails. | |
390 | * Also, thread_field->fd can be -1 if open_perf_fd() fails. | |
391 | */ | |
20142124 | 392 | lttng_perf_lock(); |
d58d1454 MD |
393 | cds_list_add_rcu(&thread_field->rcu_field_node, |
394 | &perf_thread->rcu_field_list); | |
395 | cds_list_add(&thread_field->thread_field_node, | |
396 | &perf_field->thread_field_list); | |
20142124 | 397 | lttng_perf_unlock(); |
d58d1454 MD |
398 | skip: |
399 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
400 | if (ret) | |
401 | abort(); | |
402 | return thread_field; | |
403 | } | |
404 | ||
405 | static | |
406 | struct lttng_perf_counter_thread_field * | |
407 | get_thread_field(struct lttng_perf_counter_field *field) | |
408 | { | |
409 | struct lttng_perf_counter_thread *perf_thread; | |
410 | struct lttng_perf_counter_thread_field *thread_field; | |
411 | ||
412 | perf_thread = pthread_getspecific(perf_counter_key); | |
413 | if (!perf_thread) | |
414 | perf_thread = alloc_perf_counter_thread(); | |
415 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
416 | rcu_field_node) { | |
417 | if (thread_field->field == field) | |
418 | return thread_field; | |
419 | } | |
420 | /* perf_counter_thread_field not found, need to add one */ | |
421 | return add_thread_field(field, perf_thread); | |
422 | } | |
423 | ||
424 | static | |
425 | uint64_t wrapper_perf_counter_read(struct lttng_ctx_field *field) | |
426 | { | |
427 | struct lttng_perf_counter_field *perf_field; | |
428 | struct lttng_perf_counter_thread_field *perf_thread_field; | |
429 | ||
430 | perf_field = field->u.perf_counter; | |
431 | perf_thread_field = get_thread_field(perf_field); | |
a3a8d943 | 432 | return arch_read_perf_counter(perf_thread_field); |
d58d1454 MD |
433 | } |
434 | ||
435 | static | |
436 | void perf_counter_record(struct lttng_ctx_field *field, | |
437 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
438 | struct lttng_channel *chan) | |
439 | { | |
440 | uint64_t value; | |
441 | ||
442 | value = wrapper_perf_counter_read(field); | |
443 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); | |
444 | chan->ops->event_write(ctx, &value, sizeof(value)); | |
445 | } | |
446 | ||
447 | static | |
448 | void perf_counter_get_value(struct lttng_ctx_field *field, | |
53569322 | 449 | struct lttng_ctx_value *value) |
d58d1454 | 450 | { |
6e9ac4ae | 451 | value->u.s64 = wrapper_perf_counter_read(field); |
d58d1454 MD |
452 | } |
453 | ||
20142124 | 454 | /* Called with perf lock held */ |
d58d1454 MD |
455 | static |
456 | void lttng_destroy_perf_thread_field( | |
457 | struct lttng_perf_counter_thread_field *thread_field) | |
458 | { | |
b9389e6e | 459 | close_perf_fd(thread_field->fd); |
d58d1454 MD |
460 | unmap_perf_page(thread_field->pc); |
461 | cds_list_del_rcu(&thread_field->rcu_field_node); | |
462 | cds_list_del(&thread_field->thread_field_node); | |
463 | free(thread_field); | |
464 | } | |
465 | ||
466 | static | |
467 | void lttng_destroy_perf_thread_key(void *_key) | |
468 | { | |
469 | struct lttng_perf_counter_thread *perf_thread = _key; | |
470 | struct lttng_perf_counter_thread_field *pos, *p; | |
471 | ||
20142124 | 472 | lttng_perf_lock(); |
d58d1454 MD |
473 | cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list, |
474 | rcu_field_node) | |
475 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 476 | lttng_perf_unlock(); |
d58d1454 MD |
477 | free(perf_thread); |
478 | } | |
479 | ||
480 | /* Called with UST lock held */ | |
481 | static | |
482 | void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field) | |
483 | { | |
484 | struct lttng_perf_counter_field *perf_field; | |
485 | struct lttng_perf_counter_thread_field *pos, *p; | |
486 | ||
487 | free((char *) field->event_field.name); | |
488 | perf_field = field->u.perf_counter; | |
489 | /* | |
490 | * This put is performed when no threads can concurrently | |
491 | * perform a "get" concurrently, thanks to urcu-bp grace | |
20142124 MD |
492 | * period. Holding the lttng perf lock protects against |
493 | * concurrent modification of the per-thread thread field | |
494 | * list. | |
d58d1454 | 495 | */ |
20142124 | 496 | lttng_perf_lock(); |
d58d1454 MD |
497 | cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list, |
498 | thread_field_node) | |
499 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 500 | lttng_perf_unlock(); |
d58d1454 MD |
501 | free(perf_field); |
502 | } | |
503 | ||
d286ad50 JD |
504 | #ifdef __ARM_ARCH_7A__ |
505 | ||
506 | static | |
507 | int perf_get_exclude_kernel(void) | |
508 | { | |
509 | return 0; | |
510 | } | |
511 | ||
512 | #else /* __ARM_ARCH_7A__ */ | |
513 | ||
514 | static | |
515 | int perf_get_exclude_kernel(void) | |
516 | { | |
517 | return 1; | |
518 | } | |
519 | ||
520 | #endif /* __ARM_ARCH_7A__ */ | |
521 | ||
d58d1454 MD |
522 | /* Called with UST lock held */ |
523 | int lttng_add_perf_counter_to_ctx(uint32_t type, | |
524 | uint64_t config, | |
525 | const char *name, | |
526 | struct lttng_ctx **ctx) | |
527 | { | |
528 | struct lttng_ctx_field *field; | |
529 | struct lttng_perf_counter_field *perf_field; | |
d58d1454 MD |
530 | char *name_alloc; |
531 | int ret; | |
532 | ||
533 | name_alloc = strdup(name); | |
534 | if (!name_alloc) { | |
535 | ret = -ENOMEM; | |
536 | goto name_alloc_error; | |
537 | } | |
538 | perf_field = zmalloc(sizeof(*perf_field)); | |
539 | if (!perf_field) { | |
540 | ret = -ENOMEM; | |
541 | goto perf_field_alloc_error; | |
542 | } | |
543 | field = lttng_append_context(ctx); | |
544 | if (!field) { | |
545 | ret = -ENOMEM; | |
546 | goto append_context_error; | |
547 | } | |
548 | if (lttng_find_context(*ctx, name_alloc)) { | |
549 | ret = -EEXIST; | |
550 | goto find_error; | |
551 | } | |
552 | ||
553 | field->destroy = lttng_destroy_perf_counter_field; | |
554 | ||
555 | field->event_field.name = name_alloc; | |
556 | field->event_field.type.atype = atype_integer; | |
218deb69 | 557 | field->event_field.type.u.integer.size = |
d58d1454 | 558 | sizeof(uint64_t) * CHAR_BIT; |
218deb69 | 559 | field->event_field.type.u.integer.alignment = |
d58d1454 | 560 | lttng_alignof(uint64_t) * CHAR_BIT; |
218deb69 | 561 | field->event_field.type.u.integer.signedness = |
d58d1454 | 562 | lttng_is_signed_type(uint64_t); |
218deb69 MD |
563 | field->event_field.type.u.integer.reverse_byte_order = 0; |
564 | field->event_field.type.u.integer.base = 10; | |
565 | field->event_field.type.u.integer.encoding = lttng_encode_none; | |
d58d1454 MD |
566 | field->get_size = perf_counter_get_size; |
567 | field->record = perf_counter_record; | |
568 | field->get_value = perf_counter_get_value; | |
569 | ||
570 | perf_field->attr.type = type; | |
571 | perf_field->attr.config = config; | |
d286ad50 | 572 | perf_field->attr.exclude_kernel = perf_get_exclude_kernel(); |
d58d1454 MD |
573 | CDS_INIT_LIST_HEAD(&perf_field->thread_field_list); |
574 | field->u.perf_counter = perf_field; | |
575 | ||
576 | /* Ensure that this perf counter can be used in this process. */ | |
b9389e6e JD |
577 | ret = open_perf_fd(&perf_field->attr); |
578 | if (ret < 0) { | |
d58d1454 MD |
579 | ret = -ENODEV; |
580 | goto setup_error; | |
581 | } | |
b9389e6e | 582 | close_perf_fd(ret); |
d58d1454 MD |
583 | |
584 | /* | |
585 | * Contexts can only be added before tracing is started, so we | |
586 | * don't have to synchronize against concurrent threads using | |
587 | * the field here. | |
588 | */ | |
589 | ||
b2cc986a | 590 | lttng_context_update(*ctx); |
d58d1454 MD |
591 | return 0; |
592 | ||
593 | setup_error: | |
594 | find_error: | |
595 | lttng_remove_context_field(ctx, field); | |
596 | append_context_error: | |
597 | free(perf_field); | |
598 | perf_field_alloc_error: | |
599 | free(name_alloc); | |
600 | name_alloc_error: | |
601 | return ret; | |
602 | } | |
603 | ||
604 | int lttng_perf_counter_init(void) | |
605 | { | |
606 | int ret; | |
607 | ||
608 | ret = pthread_key_create(&perf_counter_key, | |
609 | lttng_destroy_perf_thread_key); | |
610 | if (ret) | |
611 | ret = -ret; | |
612 | return ret; | |
613 | } | |
614 | ||
615 | void lttng_perf_counter_exit(void) | |
616 | { | |
617 | int ret; | |
618 | ||
619 | ret = pthread_key_delete(perf_counter_key); | |
620 | if (ret) { | |
621 | errno = ret; | |
622 | PERROR("Error in pthread_key_delete"); | |
623 | } | |
624 | } |