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> | |
0466ac28 | 22 | #include <lttng/ringbuffer-context.h> |
d58d1454 MD |
23 | #include <urcu/system.h> |
24 | #include <urcu/arch.h> | |
25 | #include <urcu/rculist.h> | |
864a1eda | 26 | #include <ust-helper.h> |
d58d1454 MD |
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" |
fc80554e MJ |
32 | |
33 | #include "context-internal.h" | |
d58d1454 | 34 | #include "lttng-tracer-core.h" |
bd8c1787 | 35 | #include "ust-events-internal.h" |
d58d1454 MD |
36 | |
37 | /* | |
38 | * We use a global perf counter key and iterate on per-thread RCU lists | |
39 | * of fields in the fast path, even though this is not strictly speaking | |
40 | * what would provide the best fast-path complexity, to ensure teardown | |
41 | * of sessions vs thread exit is handled racelessly. | |
42 | * | |
43 | * Updates and traversals of thread_list are protected by UST lock. | |
44 | * Updates to rcu_field_list are protected by UST lock. | |
45 | */ | |
46 | ||
47 | struct lttng_perf_counter_thread_field { | |
48 | struct lttng_perf_counter_field *field; /* Back reference */ | |
49 | struct perf_event_mmap_page *pc; | |
50 | struct cds_list_head thread_field_node; /* Per-field list of thread fields (node) */ | |
51 | struct cds_list_head rcu_field_node; /* RCU per-thread list of fields (node) */ | |
b9389e6e | 52 | int fd; /* Perf FD */ |
d58d1454 MD |
53 | }; |
54 | ||
55 | struct lttng_perf_counter_thread { | |
56 | struct cds_list_head rcu_field_list; /* RCU per-thread list of fields */ | |
57 | }; | |
58 | ||
59 | struct lttng_perf_counter_field { | |
60 | struct perf_event_attr attr; | |
61 | struct cds_list_head thread_field_list; /* Per-field list of thread fields */ | |
62 | }; | |
63 | ||
64 | static pthread_key_t perf_counter_key; | |
65 | ||
20142124 MD |
66 | /* |
67 | * lttng_perf_lock - Protect lttng-ust perf counter data structures | |
68 | * | |
69 | * Nests within the ust_lock, and therefore within the libc dl lock. | |
70 | * Therefore, we need to fixup the TLS before nesting into this lock. | |
71 | * Nests inside RCU bp read-side lock. Protects against concurrent | |
72 | * fork. | |
73 | */ | |
74 | static pthread_mutex_t ust_perf_mutex = PTHREAD_MUTEX_INITIALIZER; | |
75 | ||
76 | /* | |
77 | * Cancel state when grabbing the ust_perf_mutex. Saved when locking, | |
78 | * restored on unlock. Protected by ust_perf_mutex. | |
79 | */ | |
80 | static int ust_perf_saved_cancelstate; | |
81 | ||
82 | /* | |
83 | * Track whether we are tracing from a signal handler nested on an | |
84 | * application thread. | |
85 | */ | |
86 | static DEFINE_URCU_TLS(int, ust_perf_mutex_nest); | |
87 | ||
88 | /* | |
89 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
90 | */ | |
91 | void lttng_ust_fixup_perf_counter_tls(void) | |
92 | { | |
93 | asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest))); | |
94 | } | |
95 | ||
96 | void lttng_perf_lock(void) | |
97 | { | |
98 | sigset_t sig_all_blocked, orig_mask; | |
99 | int ret, oldstate; | |
100 | ||
101 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); | |
102 | if (ret) { | |
103 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
104 | } | |
105 | sigfillset(&sig_all_blocked); | |
106 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
107 | if (ret) { | |
108 | ERR("pthread_sigmask: %s", strerror(ret)); | |
109 | } | |
110 | if (!URCU_TLS(ust_perf_mutex_nest)++) { | |
111 | /* | |
112 | * Ensure the compiler don't move the store after the close() | |
113 | * call in case close() would be marked as leaf. | |
114 | */ | |
115 | cmm_barrier(); | |
116 | pthread_mutex_lock(&ust_perf_mutex); | |
117 | ust_perf_saved_cancelstate = oldstate; | |
118 | } | |
119 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
120 | if (ret) { | |
121 | ERR("pthread_sigmask: %s", strerror(ret)); | |
122 | } | |
123 | } | |
124 | ||
125 | void lttng_perf_unlock(void) | |
126 | { | |
127 | sigset_t sig_all_blocked, orig_mask; | |
128 | int ret, newstate, oldstate; | |
129 | bool restore_cancel = false; | |
130 | ||
131 | sigfillset(&sig_all_blocked); | |
132 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
133 | if (ret) { | |
134 | ERR("pthread_sigmask: %s", strerror(ret)); | |
135 | } | |
136 | /* | |
137 | * Ensure the compiler don't move the store before the close() | |
138 | * call, in case close() would be marked as leaf. | |
139 | */ | |
140 | cmm_barrier(); | |
141 | if (!--URCU_TLS(ust_perf_mutex_nest)) { | |
142 | newstate = ust_perf_saved_cancelstate; | |
143 | restore_cancel = true; | |
144 | pthread_mutex_unlock(&ust_perf_mutex); | |
145 | } | |
146 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
147 | if (ret) { | |
148 | ERR("pthread_sigmask: %s", strerror(ret)); | |
149 | } | |
150 | if (restore_cancel) { | |
151 | ret = pthread_setcancelstate(newstate, &oldstate); | |
152 | if (ret) { | |
153 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
154 | } | |
155 | } | |
156 | } | |
157 | ||
d58d1454 | 158 | static |
daacdbfc | 159 | size_t perf_counter_get_size(struct lttng_ust_ctx_field *field, size_t offset) |
d58d1454 MD |
160 | { |
161 | size_t size = 0; | |
162 | ||
163 | size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); | |
164 | size += sizeof(uint64_t); | |
165 | return size; | |
166 | } | |
167 | ||
a3a8d943 MD |
168 | static |
169 | uint64_t read_perf_counter_syscall( | |
170 | struct lttng_perf_counter_thread_field *thread_field) | |
171 | { | |
172 | uint64_t count; | |
173 | ||
174 | if (caa_unlikely(thread_field->fd < 0)) | |
175 | return 0; | |
176 | ||
177 | if (caa_unlikely(read(thread_field->fd, &count, sizeof(count)) | |
178 | < sizeof(count))) | |
179 | return 0; | |
180 | ||
181 | return count; | |
182 | } | |
183 | ||
d58d1454 MD |
184 | #if defined(__x86_64__) || defined(__i386__) |
185 | ||
186 | static | |
187 | uint64_t rdpmc(unsigned int counter) | |
188 | { | |
189 | unsigned int low, high; | |
190 | ||
191 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
192 | ||
193 | return low | ((uint64_t) high) << 32; | |
194 | } | |
195 | ||
77d7fa98 MD |
196 | static |
197 | bool has_rdpmc(struct perf_event_mmap_page *pc) | |
198 | { | |
199 | if (caa_unlikely(!pc->cap_bit0_is_deprecated)) | |
200 | return false; | |
201 | /* Since Linux kernel 3.12. */ | |
202 | return pc->cap_user_rdpmc; | |
203 | } | |
204 | ||
d58d1454 | 205 | static |
a3a8d943 | 206 | uint64_t arch_read_perf_counter( |
d286ad50 | 207 | struct lttng_perf_counter_thread_field *thread_field) |
d58d1454 MD |
208 | { |
209 | uint32_t seq, idx; | |
210 | uint64_t count; | |
d286ad50 | 211 | struct perf_event_mmap_page *pc = thread_field->pc; |
d58d1454 MD |
212 | |
213 | if (caa_unlikely(!pc)) | |
214 | return 0; | |
215 | ||
216 | do { | |
217 | seq = CMM_LOAD_SHARED(pc->lock); | |
218 | cmm_barrier(); | |
219 | ||
220 | idx = pc->index; | |
77d7fa98 | 221 | if (caa_likely(has_rdpmc(pc) && idx)) { |
4f58f54f MD |
222 | int64_t pmcval; |
223 | ||
224 | pmcval = rdpmc(idx - 1); | |
225 | /* Sign-extend the pmc register result. */ | |
226 | pmcval <<= 64 - pc->pmc_width; | |
227 | pmcval >>= 64 - pc->pmc_width; | |
228 | count = pc->offset + pmcval; | |
229 | } else { | |
a3a8d943 MD |
230 | /* Fall-back on system call if rdpmc cannot be used. */ |
231 | return read_perf_counter_syscall(thread_field); | |
4f58f54f | 232 | } |
d58d1454 MD |
233 | cmm_barrier(); |
234 | } while (CMM_LOAD_SHARED(pc->lock) != seq); | |
235 | ||
236 | return count; | |
237 | } | |
238 | ||
d286ad50 | 239 | static |
a3a8d943 | 240 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) |
d286ad50 | 241 | { |
a3a8d943 | 242 | struct perf_event_mmap_page *pc = thread_field->pc; |
d286ad50 | 243 | |
a3a8d943 | 244 | if (!pc) |
d286ad50 | 245 | return 0; |
77d7fa98 | 246 | return !has_rdpmc(pc); |
a3a8d943 | 247 | } |
d286ad50 | 248 | |
a3a8d943 | 249 | #else |
d286ad50 | 250 | |
a3a8d943 MD |
251 | /* Generic (slow) implementation using a read system call. */ |
252 | static | |
253 | uint64_t arch_read_perf_counter( | |
254 | struct lttng_perf_counter_thread_field *thread_field) | |
255 | { | |
256 | return read_perf_counter_syscall(thread_field); | |
d286ad50 JD |
257 | } |
258 | ||
a3a8d943 MD |
259 | static |
260 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) | |
261 | { | |
262 | return 1; | |
263 | } | |
d286ad50 | 264 | |
a3a8d943 | 265 | #endif |
d286ad50 | 266 | |
d58d1454 MD |
267 | static |
268 | int sys_perf_event_open(struct perf_event_attr *attr, | |
269 | pid_t pid, int cpu, int group_fd, | |
270 | unsigned long flags) | |
271 | { | |
272 | return syscall(SYS_perf_event_open, attr, pid, cpu, | |
273 | group_fd, flags); | |
274 | } | |
275 | ||
276 | static | |
b9389e6e | 277 | int open_perf_fd(struct perf_event_attr *attr) |
d58d1454 | 278 | { |
b9389e6e | 279 | int fd; |
d58d1454 MD |
280 | |
281 | fd = sys_perf_event_open(attr, 0, -1, -1, 0); | |
282 | if (fd < 0) | |
b9389e6e JD |
283 | return -1; |
284 | ||
285 | return fd; | |
286 | } | |
287 | ||
d286ad50 JD |
288 | static |
289 | void close_perf_fd(int fd) | |
290 | { | |
291 | int ret; | |
292 | ||
293 | if (fd < 0) | |
294 | return; | |
295 | ||
296 | ret = close(fd); | |
297 | if (ret) { | |
298 | perror("Error closing LTTng-UST perf memory mapping FD"); | |
299 | } | |
300 | } | |
301 | ||
77d7fa98 | 302 | static void setup_perf(struct lttng_perf_counter_thread_field *thread_field) |
b9389e6e JD |
303 | { |
304 | void *perf_addr; | |
d58d1454 MD |
305 | |
306 | perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page), | |
b9389e6e | 307 | PROT_READ, MAP_SHARED, thread_field->fd, 0); |
d58d1454 | 308 | if (perf_addr == MAP_FAILED) |
b9389e6e | 309 | perf_addr = NULL; |
77d7fa98 | 310 | thread_field->pc = perf_addr; |
b9389e6e | 311 | |
a3a8d943 | 312 | if (!arch_perf_keep_fd(thread_field)) { |
b9389e6e JD |
313 | close_perf_fd(thread_field->fd); |
314 | thread_field->fd = -1; | |
6c2125af | 315 | } |
d58d1454 MD |
316 | } |
317 | ||
318 | static | |
319 | void unmap_perf_page(struct perf_event_mmap_page *pc) | |
320 | { | |
321 | int ret; | |
322 | ||
323 | if (!pc) | |
324 | return; | |
325 | ret = munmap(pc, sizeof(struct perf_event_mmap_page)); | |
326 | if (ret < 0) { | |
327 | PERROR("Error in munmap"); | |
328 | abort(); | |
329 | } | |
330 | } | |
331 | ||
332 | static | |
333 | struct lttng_perf_counter_thread *alloc_perf_counter_thread(void) | |
334 | { | |
335 | struct lttng_perf_counter_thread *perf_thread; | |
336 | sigset_t newmask, oldmask; | |
337 | int ret; | |
338 | ||
339 | ret = sigfillset(&newmask); | |
340 | if (ret) | |
341 | abort(); | |
342 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
343 | if (ret) | |
344 | abort(); | |
345 | /* Check again with signals disabled */ | |
346 | perf_thread = pthread_getspecific(perf_counter_key); | |
347 | if (perf_thread) | |
348 | goto skip; | |
349 | perf_thread = zmalloc(sizeof(*perf_thread)); | |
350 | if (!perf_thread) | |
351 | abort(); | |
352 | CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list); | |
353 | ret = pthread_setspecific(perf_counter_key, perf_thread); | |
354 | if (ret) | |
355 | abort(); | |
356 | skip: | |
357 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
358 | if (ret) | |
359 | abort(); | |
360 | return perf_thread; | |
361 | } | |
362 | ||
363 | static | |
364 | struct lttng_perf_counter_thread_field * | |
365 | add_thread_field(struct lttng_perf_counter_field *perf_field, | |
366 | struct lttng_perf_counter_thread *perf_thread) | |
367 | { | |
368 | struct lttng_perf_counter_thread_field *thread_field; | |
369 | sigset_t newmask, oldmask; | |
370 | int ret; | |
371 | ||
372 | ret = sigfillset(&newmask); | |
373 | if (ret) | |
374 | abort(); | |
375 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
376 | if (ret) | |
377 | abort(); | |
378 | /* Check again with signals disabled */ | |
379 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
380 | rcu_field_node) { | |
381 | if (thread_field->field == perf_field) | |
382 | goto skip; | |
383 | } | |
384 | thread_field = zmalloc(sizeof(*thread_field)); | |
385 | if (!thread_field) | |
386 | abort(); | |
387 | thread_field->field = perf_field; | |
b9389e6e JD |
388 | thread_field->fd = open_perf_fd(&perf_field->attr); |
389 | if (thread_field->fd >= 0) | |
77d7fa98 | 390 | setup_perf(thread_field); |
b9389e6e JD |
391 | /* |
392 | * Note: thread_field->pc can be NULL if setup_perf() fails. | |
393 | * Also, thread_field->fd can be -1 if open_perf_fd() fails. | |
394 | */ | |
20142124 | 395 | lttng_perf_lock(); |
d58d1454 MD |
396 | cds_list_add_rcu(&thread_field->rcu_field_node, |
397 | &perf_thread->rcu_field_list); | |
398 | cds_list_add(&thread_field->thread_field_node, | |
399 | &perf_field->thread_field_list); | |
20142124 | 400 | lttng_perf_unlock(); |
d58d1454 MD |
401 | skip: |
402 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
403 | if (ret) | |
404 | abort(); | |
405 | return thread_field; | |
406 | } | |
407 | ||
408 | static | |
409 | struct lttng_perf_counter_thread_field * | |
410 | get_thread_field(struct lttng_perf_counter_field *field) | |
411 | { | |
412 | struct lttng_perf_counter_thread *perf_thread; | |
413 | struct lttng_perf_counter_thread_field *thread_field; | |
414 | ||
415 | perf_thread = pthread_getspecific(perf_counter_key); | |
416 | if (!perf_thread) | |
417 | perf_thread = alloc_perf_counter_thread(); | |
418 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
419 | rcu_field_node) { | |
420 | if (thread_field->field == field) | |
421 | return thread_field; | |
422 | } | |
423 | /* perf_counter_thread_field not found, need to add one */ | |
424 | return add_thread_field(field, perf_thread); | |
425 | } | |
426 | ||
427 | static | |
daacdbfc | 428 | uint64_t wrapper_perf_counter_read(struct lttng_ust_ctx_field *field) |
d58d1454 MD |
429 | { |
430 | struct lttng_perf_counter_field *perf_field; | |
431 | struct lttng_perf_counter_thread_field *perf_thread_field; | |
432 | ||
daacdbfc | 433 | perf_field = (struct lttng_perf_counter_field *) field->priv; |
d58d1454 | 434 | perf_thread_field = get_thread_field(perf_field); |
a3a8d943 | 435 | return arch_read_perf_counter(perf_thread_field); |
d58d1454 MD |
436 | } |
437 | ||
438 | static | |
daacdbfc | 439 | void perf_counter_record(struct lttng_ust_ctx_field *field, |
d58d1454 MD |
440 | struct lttng_ust_lib_ring_buffer_ctx *ctx, |
441 | struct lttng_channel *chan) | |
442 | { | |
443 | uint64_t value; | |
444 | ||
445 | value = wrapper_perf_counter_read(field); | |
446 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); | |
447 | chan->ops->event_write(ctx, &value, sizeof(value)); | |
448 | } | |
449 | ||
450 | static | |
daacdbfc MD |
451 | void perf_counter_get_value(struct lttng_ust_ctx_field *field, |
452 | struct lttng_ust_ctx_value *value) | |
d58d1454 | 453 | { |
6e9ac4ae | 454 | value->u.s64 = wrapper_perf_counter_read(field); |
d58d1454 MD |
455 | } |
456 | ||
20142124 | 457 | /* Called with perf lock held */ |
d58d1454 MD |
458 | static |
459 | void lttng_destroy_perf_thread_field( | |
460 | struct lttng_perf_counter_thread_field *thread_field) | |
461 | { | |
b9389e6e | 462 | close_perf_fd(thread_field->fd); |
d58d1454 MD |
463 | unmap_perf_page(thread_field->pc); |
464 | cds_list_del_rcu(&thread_field->rcu_field_node); | |
465 | cds_list_del(&thread_field->thread_field_node); | |
466 | free(thread_field); | |
467 | } | |
468 | ||
469 | static | |
470 | void lttng_destroy_perf_thread_key(void *_key) | |
471 | { | |
472 | struct lttng_perf_counter_thread *perf_thread = _key; | |
473 | struct lttng_perf_counter_thread_field *pos, *p; | |
474 | ||
20142124 | 475 | lttng_perf_lock(); |
d58d1454 MD |
476 | cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list, |
477 | rcu_field_node) | |
478 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 479 | lttng_perf_unlock(); |
d58d1454 MD |
480 | free(perf_thread); |
481 | } | |
482 | ||
483 | /* Called with UST lock held */ | |
484 | static | |
daacdbfc | 485 | void lttng_destroy_perf_counter_field(struct lttng_ust_ctx_field *field) |
d58d1454 MD |
486 | { |
487 | struct lttng_perf_counter_field *perf_field; | |
488 | struct lttng_perf_counter_thread_field *pos, *p; | |
489 | ||
daacdbfc MD |
490 | free((char *) field->event_field->name); |
491 | perf_field = (struct lttng_perf_counter_field *) field->priv; | |
d58d1454 MD |
492 | /* |
493 | * This put is performed when no threads can concurrently | |
494 | * perform a "get" concurrently, thanks to urcu-bp grace | |
20142124 MD |
495 | * period. Holding the lttng perf lock protects against |
496 | * concurrent modification of the per-thread thread field | |
497 | * list. | |
d58d1454 | 498 | */ |
20142124 | 499 | lttng_perf_lock(); |
d58d1454 MD |
500 | cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list, |
501 | thread_field_node) | |
502 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 503 | lttng_perf_unlock(); |
d58d1454 MD |
504 | free(perf_field); |
505 | } | |
506 | ||
d286ad50 JD |
507 | #ifdef __ARM_ARCH_7A__ |
508 | ||
509 | static | |
510 | int perf_get_exclude_kernel(void) | |
511 | { | |
512 | return 0; | |
513 | } | |
514 | ||
515 | #else /* __ARM_ARCH_7A__ */ | |
516 | ||
517 | static | |
518 | int perf_get_exclude_kernel(void) | |
519 | { | |
520 | return 1; | |
521 | } | |
522 | ||
523 | #endif /* __ARM_ARCH_7A__ */ | |
524 | ||
d58d1454 MD |
525 | /* Called with UST lock held */ |
526 | int lttng_add_perf_counter_to_ctx(uint32_t type, | |
527 | uint64_t config, | |
528 | const char *name, | |
daacdbfc | 529 | struct lttng_ust_ctx **ctx) |
d58d1454 | 530 | { |
daacdbfc | 531 | struct lttng_ust_ctx_field *field; |
a084756d | 532 | struct lttng_ust_type_common *ust_type; |
d58d1454 | 533 | struct lttng_perf_counter_field *perf_field; |
d58d1454 MD |
534 | char *name_alloc; |
535 | int ret; | |
536 | ||
537 | name_alloc = strdup(name); | |
538 | if (!name_alloc) { | |
539 | ret = -ENOMEM; | |
540 | goto name_alloc_error; | |
541 | } | |
542 | perf_field = zmalloc(sizeof(*perf_field)); | |
543 | if (!perf_field) { | |
544 | ret = -ENOMEM; | |
545 | goto perf_field_alloc_error; | |
546 | } | |
a084756d MD |
547 | ust_type = lttng_ust_create_type_integer(sizeof(uint64_t) * CHAR_BIT, |
548 | lttng_alignof(uint64_t) * CHAR_BIT, | |
549 | lttng_is_signed_type(uint64_t), | |
550 | BYTE_ORDER, 10); | |
551 | if (!type) { | |
552 | ret = -ENOMEM; | |
553 | goto type_alloc_error; | |
554 | } | |
d58d1454 MD |
555 | field = lttng_append_context(ctx); |
556 | if (!field) { | |
557 | ret = -ENOMEM; | |
558 | goto append_context_error; | |
559 | } | |
560 | if (lttng_find_context(*ctx, name_alloc)) { | |
561 | ret = -EEXIST; | |
562 | goto find_error; | |
563 | } | |
564 | ||
565 | field->destroy = lttng_destroy_perf_counter_field; | |
566 | ||
daacdbfc | 567 | field->event_field->name = name_alloc; |
a084756d | 568 | field->event_field->type = ust_type; |
d58d1454 MD |
569 | field->get_size = perf_counter_get_size; |
570 | field->record = perf_counter_record; | |
571 | field->get_value = perf_counter_get_value; | |
572 | ||
573 | perf_field->attr.type = type; | |
574 | perf_field->attr.config = config; | |
d286ad50 | 575 | perf_field->attr.exclude_kernel = perf_get_exclude_kernel(); |
d58d1454 | 576 | CDS_INIT_LIST_HEAD(&perf_field->thread_field_list); |
daacdbfc | 577 | field->priv = perf_field; |
d58d1454 MD |
578 | |
579 | /* Ensure that this perf counter can be used in this process. */ | |
b9389e6e JD |
580 | ret = open_perf_fd(&perf_field->attr); |
581 | if (ret < 0) { | |
d58d1454 MD |
582 | ret = -ENODEV; |
583 | goto setup_error; | |
584 | } | |
b9389e6e | 585 | close_perf_fd(ret); |
d58d1454 MD |
586 | |
587 | /* | |
588 | * Contexts can only be added before tracing is started, so we | |
589 | * don't have to synchronize against concurrent threads using | |
590 | * the field here. | |
591 | */ | |
592 | ||
b2cc986a | 593 | lttng_context_update(*ctx); |
d58d1454 MD |
594 | return 0; |
595 | ||
596 | setup_error: | |
597 | find_error: | |
598 | lttng_remove_context_field(ctx, field); | |
599 | append_context_error: | |
a084756d MD |
600 | lttng_ust_destroy_type(ust_type); |
601 | type_alloc_error: | |
d58d1454 MD |
602 | free(perf_field); |
603 | perf_field_alloc_error: | |
604 | free(name_alloc); | |
605 | name_alloc_error: | |
606 | return ret; | |
607 | } | |
608 | ||
609 | int lttng_perf_counter_init(void) | |
610 | { | |
611 | int ret; | |
612 | ||
613 | ret = pthread_key_create(&perf_counter_key, | |
614 | lttng_destroy_perf_thread_key); | |
615 | if (ret) | |
616 | ret = -ret; | |
617 | return ret; | |
618 | } | |
619 | ||
620 | void lttng_perf_counter_exit(void) | |
621 | { | |
622 | int ret; | |
623 | ||
624 | ret = pthread_key_delete(perf_counter_key); | |
625 | if (ret) { | |
626 | errno = ret; | |
627 | PERROR("Error in pthread_key_delete"); | |
628 | } | |
629 | } |