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 |
9af5d97a | 10 | #include <limits.h> |
d58d1454 MD |
11 | #include <sys/types.h> |
12 | #include <unistd.h> | |
13 | #include <string.h> | |
14 | #include <stdlib.h> | |
15 | #include <stdio.h> | |
649fb6b3 | 16 | #include <stdbool.h> |
b4051ad8 | 17 | #include <stddef.h> |
fb31eb73 | 18 | #include <stdint.h> |
d58d1454 MD |
19 | #include <sys/mman.h> |
20 | #include <sys/syscall.h> | |
2eba8e39 | 21 | #include <lttng/ust-arch.h> |
d58d1454 MD |
22 | #include <lttng/ust-events.h> |
23 | #include <lttng/ust-tracer.h> | |
0466ac28 | 24 | #include <lttng/ringbuffer-context.h> |
d58d1454 MD |
25 | #include <urcu/system.h> |
26 | #include <urcu/arch.h> | |
27 | #include <urcu/rculist.h> | |
864a1eda | 28 | #include <ust-helper.h> |
d58d1454 MD |
29 | #include <urcu/ref.h> |
30 | #include <usterr-signal-safe.h> | |
31 | #include <signal.h> | |
20142124 | 32 | #include <urcu/tls-compat.h> |
77d7fa98 | 33 | #include "perf_event.h" |
fc80554e MJ |
34 | |
35 | #include "context-internal.h" | |
d58d1454 | 36 | #include "lttng-tracer-core.h" |
bd8c1787 | 37 | #include "ust-events-internal.h" |
d58d1454 MD |
38 | |
39 | /* | |
40 | * We use a global perf counter key and iterate on per-thread RCU lists | |
41 | * of fields in the fast path, even though this is not strictly speaking | |
42 | * what would provide the best fast-path complexity, to ensure teardown | |
43 | * of sessions vs thread exit is handled racelessly. | |
44 | * | |
45 | * Updates and traversals of thread_list are protected by UST lock. | |
46 | * Updates to rcu_field_list are protected by UST lock. | |
47 | */ | |
48 | ||
49 | struct lttng_perf_counter_thread_field { | |
50 | struct lttng_perf_counter_field *field; /* Back reference */ | |
51 | struct perf_event_mmap_page *pc; | |
52 | struct cds_list_head thread_field_node; /* Per-field list of thread fields (node) */ | |
53 | struct cds_list_head rcu_field_node; /* RCU per-thread list of fields (node) */ | |
b9389e6e | 54 | int fd; /* Perf FD */ |
d58d1454 MD |
55 | }; |
56 | ||
57 | struct lttng_perf_counter_thread { | |
58 | struct cds_list_head rcu_field_list; /* RCU per-thread list of fields */ | |
59 | }; | |
60 | ||
61 | struct lttng_perf_counter_field { | |
62 | struct perf_event_attr attr; | |
63 | struct cds_list_head thread_field_list; /* Per-field list of thread fields */ | |
64 | }; | |
65 | ||
66 | static pthread_key_t perf_counter_key; | |
67 | ||
20142124 MD |
68 | /* |
69 | * lttng_perf_lock - Protect lttng-ust perf counter data structures | |
70 | * | |
71 | * Nests within the ust_lock, and therefore within the libc dl lock. | |
72 | * Therefore, we need to fixup the TLS before nesting into this lock. | |
73 | * Nests inside RCU bp read-side lock. Protects against concurrent | |
74 | * fork. | |
75 | */ | |
76 | static pthread_mutex_t ust_perf_mutex = PTHREAD_MUTEX_INITIALIZER; | |
77 | ||
78 | /* | |
79 | * Cancel state when grabbing the ust_perf_mutex. Saved when locking, | |
80 | * restored on unlock. Protected by ust_perf_mutex. | |
81 | */ | |
82 | static int ust_perf_saved_cancelstate; | |
83 | ||
84 | /* | |
85 | * Track whether we are tracing from a signal handler nested on an | |
86 | * application thread. | |
87 | */ | |
88 | static DEFINE_URCU_TLS(int, ust_perf_mutex_nest); | |
89 | ||
90 | /* | |
91 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
92 | */ | |
93 | void lttng_ust_fixup_perf_counter_tls(void) | |
94 | { | |
95 | asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest))); | |
96 | } | |
97 | ||
98 | void lttng_perf_lock(void) | |
99 | { | |
100 | sigset_t sig_all_blocked, orig_mask; | |
101 | int ret, oldstate; | |
102 | ||
103 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); | |
104 | if (ret) { | |
105 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
106 | } | |
107 | sigfillset(&sig_all_blocked); | |
108 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
109 | if (ret) { | |
110 | ERR("pthread_sigmask: %s", strerror(ret)); | |
111 | } | |
112 | if (!URCU_TLS(ust_perf_mutex_nest)++) { | |
113 | /* | |
114 | * Ensure the compiler don't move the store after the close() | |
115 | * call in case close() would be marked as leaf. | |
116 | */ | |
117 | cmm_barrier(); | |
118 | pthread_mutex_lock(&ust_perf_mutex); | |
119 | ust_perf_saved_cancelstate = oldstate; | |
120 | } | |
121 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
122 | if (ret) { | |
123 | ERR("pthread_sigmask: %s", strerror(ret)); | |
124 | } | |
125 | } | |
126 | ||
127 | void lttng_perf_unlock(void) | |
128 | { | |
129 | sigset_t sig_all_blocked, orig_mask; | |
130 | int ret, newstate, oldstate; | |
131 | bool restore_cancel = false; | |
132 | ||
133 | sigfillset(&sig_all_blocked); | |
134 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
135 | if (ret) { | |
136 | ERR("pthread_sigmask: %s", strerror(ret)); | |
137 | } | |
138 | /* | |
139 | * Ensure the compiler don't move the store before the close() | |
140 | * call, in case close() would be marked as leaf. | |
141 | */ | |
142 | cmm_barrier(); | |
143 | if (!--URCU_TLS(ust_perf_mutex_nest)) { | |
144 | newstate = ust_perf_saved_cancelstate; | |
145 | restore_cancel = true; | |
146 | pthread_mutex_unlock(&ust_perf_mutex); | |
147 | } | |
148 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
149 | if (ret) { | |
150 | ERR("pthread_sigmask: %s", strerror(ret)); | |
151 | } | |
152 | if (restore_cancel) { | |
153 | ret = pthread_setcancelstate(newstate, &oldstate); | |
154 | if (ret) { | |
155 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
156 | } | |
157 | } | |
158 | } | |
159 | ||
d58d1454 | 160 | static |
2208d8b5 MJ |
161 | size_t perf_counter_get_size(struct lttng_ust_ctx_field *field __attribute__((unused)), |
162 | size_t offset) | |
d58d1454 MD |
163 | { |
164 | size_t size = 0; | |
165 | ||
dc325c1d | 166 | size += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(uint64_t)); |
d58d1454 MD |
167 | size += sizeof(uint64_t); |
168 | return size; | |
169 | } | |
170 | ||
a3a8d943 MD |
171 | static |
172 | uint64_t read_perf_counter_syscall( | |
173 | struct lttng_perf_counter_thread_field *thread_field) | |
174 | { | |
175 | uint64_t count; | |
176 | ||
177 | if (caa_unlikely(thread_field->fd < 0)) | |
178 | return 0; | |
179 | ||
180 | if (caa_unlikely(read(thread_field->fd, &count, sizeof(count)) | |
181 | < sizeof(count))) | |
182 | return 0; | |
183 | ||
184 | return count; | |
185 | } | |
186 | ||
2eba8e39 | 187 | #if defined(LTTNG_UST_ARCH_X86) |
d58d1454 MD |
188 | |
189 | static | |
190 | uint64_t rdpmc(unsigned int counter) | |
191 | { | |
192 | unsigned int low, high; | |
193 | ||
194 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
195 | ||
196 | return low | ((uint64_t) high) << 32; | |
197 | } | |
198 | ||
77d7fa98 MD |
199 | static |
200 | bool has_rdpmc(struct perf_event_mmap_page *pc) | |
201 | { | |
202 | if (caa_unlikely(!pc->cap_bit0_is_deprecated)) | |
203 | return false; | |
204 | /* Since Linux kernel 3.12. */ | |
205 | return pc->cap_user_rdpmc; | |
206 | } | |
207 | ||
d58d1454 | 208 | static |
a3a8d943 | 209 | uint64_t arch_read_perf_counter( |
d286ad50 | 210 | struct lttng_perf_counter_thread_field *thread_field) |
d58d1454 MD |
211 | { |
212 | uint32_t seq, idx; | |
213 | uint64_t count; | |
d286ad50 | 214 | struct perf_event_mmap_page *pc = thread_field->pc; |
d58d1454 MD |
215 | |
216 | if (caa_unlikely(!pc)) | |
217 | return 0; | |
218 | ||
219 | do { | |
220 | seq = CMM_LOAD_SHARED(pc->lock); | |
221 | cmm_barrier(); | |
222 | ||
223 | idx = pc->index; | |
77d7fa98 | 224 | if (caa_likely(has_rdpmc(pc) && idx)) { |
4f58f54f MD |
225 | int64_t pmcval; |
226 | ||
227 | pmcval = rdpmc(idx - 1); | |
228 | /* Sign-extend the pmc register result. */ | |
229 | pmcval <<= 64 - pc->pmc_width; | |
230 | pmcval >>= 64 - pc->pmc_width; | |
231 | count = pc->offset + pmcval; | |
232 | } else { | |
a3a8d943 MD |
233 | /* Fall-back on system call if rdpmc cannot be used. */ |
234 | return read_perf_counter_syscall(thread_field); | |
4f58f54f | 235 | } |
d58d1454 MD |
236 | cmm_barrier(); |
237 | } while (CMM_LOAD_SHARED(pc->lock) != seq); | |
238 | ||
239 | return count; | |
240 | } | |
241 | ||
d286ad50 | 242 | static |
a3a8d943 | 243 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) |
d286ad50 | 244 | { |
a3a8d943 | 245 | struct perf_event_mmap_page *pc = thread_field->pc; |
d286ad50 | 246 | |
a3a8d943 | 247 | if (!pc) |
d286ad50 | 248 | return 0; |
77d7fa98 | 249 | return !has_rdpmc(pc); |
a3a8d943 | 250 | } |
d286ad50 | 251 | |
a3a8d943 | 252 | #else |
d286ad50 | 253 | |
a3a8d943 MD |
254 | /* Generic (slow) implementation using a read system call. */ |
255 | static | |
256 | uint64_t arch_read_perf_counter( | |
257 | struct lttng_perf_counter_thread_field *thread_field) | |
258 | { | |
259 | return read_perf_counter_syscall(thread_field); | |
d286ad50 JD |
260 | } |
261 | ||
a3a8d943 MD |
262 | static |
263 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) | |
264 | { | |
265 | return 1; | |
266 | } | |
d286ad50 | 267 | |
a3a8d943 | 268 | #endif |
d286ad50 | 269 | |
d58d1454 MD |
270 | static |
271 | int sys_perf_event_open(struct perf_event_attr *attr, | |
272 | pid_t pid, int cpu, int group_fd, | |
273 | unsigned long flags) | |
274 | { | |
275 | return syscall(SYS_perf_event_open, attr, pid, cpu, | |
276 | group_fd, flags); | |
277 | } | |
278 | ||
279 | static | |
b9389e6e | 280 | int open_perf_fd(struct perf_event_attr *attr) |
d58d1454 | 281 | { |
b9389e6e | 282 | int fd; |
d58d1454 MD |
283 | |
284 | fd = sys_perf_event_open(attr, 0, -1, -1, 0); | |
285 | if (fd < 0) | |
b9389e6e JD |
286 | return -1; |
287 | ||
288 | return fd; | |
289 | } | |
290 | ||
d286ad50 JD |
291 | static |
292 | void close_perf_fd(int fd) | |
293 | { | |
294 | int ret; | |
295 | ||
296 | if (fd < 0) | |
297 | return; | |
298 | ||
299 | ret = close(fd); | |
300 | if (ret) { | |
301 | perror("Error closing LTTng-UST perf memory mapping FD"); | |
302 | } | |
303 | } | |
304 | ||
77d7fa98 | 305 | static void setup_perf(struct lttng_perf_counter_thread_field *thread_field) |
b9389e6e JD |
306 | { |
307 | void *perf_addr; | |
d58d1454 MD |
308 | |
309 | perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page), | |
b9389e6e | 310 | PROT_READ, MAP_SHARED, thread_field->fd, 0); |
d58d1454 | 311 | if (perf_addr == MAP_FAILED) |
b9389e6e | 312 | perf_addr = NULL; |
77d7fa98 | 313 | thread_field->pc = perf_addr; |
b9389e6e | 314 | |
a3a8d943 | 315 | if (!arch_perf_keep_fd(thread_field)) { |
b9389e6e JD |
316 | close_perf_fd(thread_field->fd); |
317 | thread_field->fd = -1; | |
6c2125af | 318 | } |
d58d1454 MD |
319 | } |
320 | ||
321 | static | |
322 | void unmap_perf_page(struct perf_event_mmap_page *pc) | |
323 | { | |
324 | int ret; | |
325 | ||
326 | if (!pc) | |
327 | return; | |
328 | ret = munmap(pc, sizeof(struct perf_event_mmap_page)); | |
329 | if (ret < 0) { | |
330 | PERROR("Error in munmap"); | |
331 | abort(); | |
332 | } | |
333 | } | |
334 | ||
335 | static | |
336 | struct lttng_perf_counter_thread *alloc_perf_counter_thread(void) | |
337 | { | |
338 | struct lttng_perf_counter_thread *perf_thread; | |
339 | sigset_t newmask, oldmask; | |
340 | int ret; | |
341 | ||
342 | ret = sigfillset(&newmask); | |
343 | if (ret) | |
344 | abort(); | |
345 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
346 | if (ret) | |
347 | abort(); | |
348 | /* Check again with signals disabled */ | |
349 | perf_thread = pthread_getspecific(perf_counter_key); | |
350 | if (perf_thread) | |
351 | goto skip; | |
352 | perf_thread = zmalloc(sizeof(*perf_thread)); | |
353 | if (!perf_thread) | |
354 | abort(); | |
355 | CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list); | |
356 | ret = pthread_setspecific(perf_counter_key, perf_thread); | |
357 | if (ret) | |
358 | abort(); | |
359 | skip: | |
360 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
361 | if (ret) | |
362 | abort(); | |
363 | return perf_thread; | |
364 | } | |
365 | ||
366 | static | |
367 | struct lttng_perf_counter_thread_field * | |
368 | add_thread_field(struct lttng_perf_counter_field *perf_field, | |
369 | struct lttng_perf_counter_thread *perf_thread) | |
370 | { | |
371 | struct lttng_perf_counter_thread_field *thread_field; | |
372 | sigset_t newmask, oldmask; | |
373 | int ret; | |
374 | ||
375 | ret = sigfillset(&newmask); | |
376 | if (ret) | |
377 | abort(); | |
378 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
379 | if (ret) | |
380 | abort(); | |
381 | /* Check again with signals disabled */ | |
382 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
383 | rcu_field_node) { | |
384 | if (thread_field->field == perf_field) | |
385 | goto skip; | |
386 | } | |
387 | thread_field = zmalloc(sizeof(*thread_field)); | |
388 | if (!thread_field) | |
389 | abort(); | |
390 | thread_field->field = perf_field; | |
b9389e6e JD |
391 | thread_field->fd = open_perf_fd(&perf_field->attr); |
392 | if (thread_field->fd >= 0) | |
77d7fa98 | 393 | setup_perf(thread_field); |
b9389e6e JD |
394 | /* |
395 | * Note: thread_field->pc can be NULL if setup_perf() fails. | |
396 | * Also, thread_field->fd can be -1 if open_perf_fd() fails. | |
397 | */ | |
20142124 | 398 | lttng_perf_lock(); |
d58d1454 MD |
399 | cds_list_add_rcu(&thread_field->rcu_field_node, |
400 | &perf_thread->rcu_field_list); | |
401 | cds_list_add(&thread_field->thread_field_node, | |
402 | &perf_field->thread_field_list); | |
20142124 | 403 | lttng_perf_unlock(); |
d58d1454 MD |
404 | skip: |
405 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
406 | if (ret) | |
407 | abort(); | |
408 | return thread_field; | |
409 | } | |
410 | ||
411 | static | |
412 | struct lttng_perf_counter_thread_field * | |
413 | get_thread_field(struct lttng_perf_counter_field *field) | |
414 | { | |
415 | struct lttng_perf_counter_thread *perf_thread; | |
416 | struct lttng_perf_counter_thread_field *thread_field; | |
417 | ||
418 | perf_thread = pthread_getspecific(perf_counter_key); | |
419 | if (!perf_thread) | |
420 | perf_thread = alloc_perf_counter_thread(); | |
421 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
422 | rcu_field_node) { | |
423 | if (thread_field->field == field) | |
424 | return thread_field; | |
425 | } | |
426 | /* perf_counter_thread_field not found, need to add one */ | |
427 | return add_thread_field(field, perf_thread); | |
428 | } | |
429 | ||
430 | static | |
daacdbfc | 431 | uint64_t wrapper_perf_counter_read(struct lttng_ust_ctx_field *field) |
d58d1454 MD |
432 | { |
433 | struct lttng_perf_counter_field *perf_field; | |
434 | struct lttng_perf_counter_thread_field *perf_thread_field; | |
435 | ||
daacdbfc | 436 | perf_field = (struct lttng_perf_counter_field *) field->priv; |
d58d1454 | 437 | perf_thread_field = get_thread_field(perf_field); |
a3a8d943 | 438 | return arch_read_perf_counter(perf_thread_field); |
d58d1454 MD |
439 | } |
440 | ||
441 | static | |
daacdbfc | 442 | void perf_counter_record(struct lttng_ust_ctx_field *field, |
d58d1454 | 443 | struct lttng_ust_lib_ring_buffer_ctx *ctx, |
e7bc0ef6 | 444 | struct lttng_ust_channel_buffer *chan) |
d58d1454 MD |
445 | { |
446 | uint64_t value; | |
447 | ||
448 | value = wrapper_perf_counter_read(field); | |
8936b6c0 | 449 | chan->ops->event_write(ctx, &value, sizeof(value), lttng_ust_rb_alignof(value)); |
d58d1454 MD |
450 | } |
451 | ||
452 | static | |
daacdbfc MD |
453 | void perf_counter_get_value(struct lttng_ust_ctx_field *field, |
454 | struct lttng_ust_ctx_value *value) | |
d58d1454 | 455 | { |
6e9ac4ae | 456 | value->u.s64 = wrapper_perf_counter_read(field); |
d58d1454 MD |
457 | } |
458 | ||
20142124 | 459 | /* Called with perf lock held */ |
d58d1454 MD |
460 | static |
461 | void lttng_destroy_perf_thread_field( | |
462 | struct lttng_perf_counter_thread_field *thread_field) | |
463 | { | |
b9389e6e | 464 | close_perf_fd(thread_field->fd); |
d58d1454 MD |
465 | unmap_perf_page(thread_field->pc); |
466 | cds_list_del_rcu(&thread_field->rcu_field_node); | |
467 | cds_list_del(&thread_field->thread_field_node); | |
468 | free(thread_field); | |
469 | } | |
470 | ||
471 | static | |
472 | void lttng_destroy_perf_thread_key(void *_key) | |
473 | { | |
474 | struct lttng_perf_counter_thread *perf_thread = _key; | |
475 | struct lttng_perf_counter_thread_field *pos, *p; | |
476 | ||
20142124 | 477 | lttng_perf_lock(); |
d58d1454 MD |
478 | cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list, |
479 | rcu_field_node) | |
480 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 481 | lttng_perf_unlock(); |
d58d1454 MD |
482 | free(perf_thread); |
483 | } | |
484 | ||
485 | /* Called with UST lock held */ | |
486 | static | |
daacdbfc | 487 | void lttng_destroy_perf_counter_field(struct lttng_ust_ctx_field *field) |
d58d1454 MD |
488 | { |
489 | struct lttng_perf_counter_field *perf_field; | |
490 | struct lttng_perf_counter_thread_field *pos, *p; | |
491 | ||
daacdbfc MD |
492 | free((char *) field->event_field->name); |
493 | perf_field = (struct lttng_perf_counter_field *) field->priv; | |
d58d1454 MD |
494 | /* |
495 | * This put is performed when no threads can concurrently | |
496 | * perform a "get" concurrently, thanks to urcu-bp grace | |
20142124 MD |
497 | * period. Holding the lttng perf lock protects against |
498 | * concurrent modification of the per-thread thread field | |
499 | * list. | |
d58d1454 | 500 | */ |
20142124 | 501 | lttng_perf_lock(); |
d58d1454 MD |
502 | cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list, |
503 | thread_field_node) | |
504 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 505 | lttng_perf_unlock(); |
d58d1454 MD |
506 | free(perf_field); |
507 | } | |
508 | ||
2eba8e39 | 509 | #ifdef LTTNG_UST_ARCH_ARMV7 |
d286ad50 JD |
510 | |
511 | static | |
512 | int perf_get_exclude_kernel(void) | |
513 | { | |
514 | return 0; | |
515 | } | |
516 | ||
2eba8e39 | 517 | #else /* LTTNG_UST_ARCH_ARMV7 */ |
d286ad50 JD |
518 | |
519 | static | |
520 | int perf_get_exclude_kernel(void) | |
521 | { | |
522 | return 1; | |
523 | } | |
524 | ||
2eba8e39 | 525 | #endif /* LTTNG_UST_ARCH_ARMV7 */ |
d286ad50 | 526 | |
d58d1454 MD |
527 | /* Called with UST lock held */ |
528 | int lttng_add_perf_counter_to_ctx(uint32_t type, | |
529 | uint64_t config, | |
530 | const char *name, | |
daacdbfc | 531 | struct lttng_ust_ctx **ctx) |
d58d1454 | 532 | { |
daacdbfc | 533 | struct lttng_ust_ctx_field *field; |
a084756d | 534 | struct lttng_ust_type_common *ust_type; |
d58d1454 | 535 | struct lttng_perf_counter_field *perf_field; |
d58d1454 MD |
536 | char *name_alloc; |
537 | int ret; | |
538 | ||
539 | name_alloc = strdup(name); | |
540 | if (!name_alloc) { | |
541 | ret = -ENOMEM; | |
542 | goto name_alloc_error; | |
543 | } | |
544 | perf_field = zmalloc(sizeof(*perf_field)); | |
545 | if (!perf_field) { | |
546 | ret = -ENOMEM; | |
547 | goto perf_field_alloc_error; | |
548 | } | |
a084756d | 549 | ust_type = lttng_ust_create_type_integer(sizeof(uint64_t) * CHAR_BIT, |
dc325c1d | 550 | lttng_ust_rb_alignof(uint64_t) * CHAR_BIT, |
eae3c729 | 551 | lttng_ust_is_signed_type(uint64_t), |
a084756d | 552 | BYTE_ORDER, 10); |
ea8efbbe | 553 | if (!ust_type) { |
a084756d MD |
554 | ret = -ENOMEM; |
555 | goto type_alloc_error; | |
556 | } | |
d58d1454 MD |
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 | ||
daacdbfc | 569 | field->event_field->name = name_alloc; |
a084756d | 570 | field->event_field->type = ust_type; |
d58d1454 MD |
571 | field->get_size = perf_counter_get_size; |
572 | field->record = perf_counter_record; | |
573 | field->get_value = perf_counter_get_value; | |
574 | ||
575 | perf_field->attr.type = type; | |
576 | perf_field->attr.config = config; | |
d286ad50 | 577 | perf_field->attr.exclude_kernel = perf_get_exclude_kernel(); |
d58d1454 | 578 | CDS_INIT_LIST_HEAD(&perf_field->thread_field_list); |
daacdbfc | 579 | field->priv = perf_field; |
d58d1454 MD |
580 | |
581 | /* Ensure that this perf counter can be used in this process. */ | |
b9389e6e JD |
582 | ret = open_perf_fd(&perf_field->attr); |
583 | if (ret < 0) { | |
d58d1454 MD |
584 | ret = -ENODEV; |
585 | goto setup_error; | |
586 | } | |
b9389e6e | 587 | close_perf_fd(ret); |
d58d1454 MD |
588 | |
589 | /* | |
590 | * Contexts can only be added before tracing is started, so we | |
591 | * don't have to synchronize against concurrent threads using | |
592 | * the field here. | |
593 | */ | |
594 | ||
b2cc986a | 595 | lttng_context_update(*ctx); |
d58d1454 MD |
596 | return 0; |
597 | ||
598 | setup_error: | |
599 | find_error: | |
600 | lttng_remove_context_field(ctx, field); | |
601 | append_context_error: | |
a084756d MD |
602 | lttng_ust_destroy_type(ust_type); |
603 | type_alloc_error: | |
d58d1454 MD |
604 | free(perf_field); |
605 | perf_field_alloc_error: | |
606 | free(name_alloc); | |
607 | name_alloc_error: | |
608 | return ret; | |
609 | } | |
610 | ||
611 | int lttng_perf_counter_init(void) | |
612 | { | |
613 | int ret; | |
614 | ||
615 | ret = pthread_key_create(&perf_counter_key, | |
616 | lttng_destroy_perf_thread_key); | |
617 | if (ret) | |
618 | ret = -ret; | |
619 | return ret; | |
620 | } | |
621 | ||
622 | void lttng_perf_counter_exit(void) | |
623 | { | |
624 | int ret; | |
625 | ||
626 | ret = pthread_key_delete(perf_counter_key); | |
627 | if (ret) { | |
628 | errno = ret; | |
629 | PERROR("Error in pthread_key_delete"); | |
630 | } | |
631 | } |