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Commit | Line | Data |
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0793a61d TG |
1 | /* |
2 | * Performance counter core code | |
3 | * | |
4 | * Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de> | |
5 | * Copyright(C) 2008 Red Hat, Inc., Ingo Molnar | |
6 | * | |
7 | * For licencing details see kernel-base/COPYING | |
8 | */ | |
9 | ||
10 | #include <linux/fs.h> | |
11 | #include <linux/cpu.h> | |
12 | #include <linux/smp.h> | |
04289bb9 | 13 | #include <linux/file.h> |
0793a61d TG |
14 | #include <linux/poll.h> |
15 | #include <linux/sysfs.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/percpu.h> | |
18 | #include <linux/uaccess.h> | |
19 | #include <linux/syscalls.h> | |
20 | #include <linux/anon_inodes.h> | |
aa9c4c0f | 21 | #include <linux/kernel_stat.h> |
0793a61d | 22 | #include <linux/perf_counter.h> |
23a185ca PM |
23 | #include <linux/mm.h> |
24 | #include <linux/vmstat.h> | |
592903cd | 25 | #include <linux/rculist.h> |
96f6d444 | 26 | #include <linux/hardirq.h> |
0793a61d | 27 | |
4e193bd4 TB |
28 | #include <asm/irq_regs.h> |
29 | ||
0793a61d TG |
30 | /* |
31 | * Each CPU has a list of per CPU counters: | |
32 | */ | |
33 | DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); | |
34 | ||
088e2852 | 35 | int perf_max_counters __read_mostly = 1; |
0793a61d TG |
36 | static int perf_reserved_percpu __read_mostly; |
37 | static int perf_overcommit __read_mostly = 1; | |
38 | ||
39 | /* | |
40 | * Mutex for (sysadmin-configurable) counter reservations: | |
41 | */ | |
42 | static DEFINE_MUTEX(perf_resource_mutex); | |
43 | ||
44 | /* | |
45 | * Architecture provided APIs - weak aliases: | |
46 | */ | |
5c92d124 | 47 | extern __weak const struct hw_perf_counter_ops * |
621a01ea | 48 | hw_perf_counter_init(struct perf_counter *counter) |
0793a61d | 49 | { |
ff6f0541 | 50 | return NULL; |
0793a61d TG |
51 | } |
52 | ||
01b2838c | 53 | u64 __weak hw_perf_save_disable(void) { return 0; } |
01ea1cca | 54 | void __weak hw_perf_restore(u64 ctrl) { barrier(); } |
01d0287f | 55 | void __weak hw_perf_counter_setup(int cpu) { barrier(); } |
3cbed429 PM |
56 | int __weak hw_perf_group_sched_in(struct perf_counter *group_leader, |
57 | struct perf_cpu_context *cpuctx, | |
58 | struct perf_counter_context *ctx, int cpu) | |
59 | { | |
60 | return 0; | |
61 | } | |
0793a61d | 62 | |
4eb96fcf PM |
63 | void __weak perf_counter_print_debug(void) { } |
64 | ||
04289bb9 IM |
65 | static void |
66 | list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) | |
67 | { | |
68 | struct perf_counter *group_leader = counter->group_leader; | |
69 | ||
70 | /* | |
71 | * Depending on whether it is a standalone or sibling counter, | |
72 | * add it straight to the context's counter list, or to the group | |
73 | * leader's sibling list: | |
74 | */ | |
75 | if (counter->group_leader == counter) | |
76 | list_add_tail(&counter->list_entry, &ctx->counter_list); | |
77 | else | |
78 | list_add_tail(&counter->list_entry, &group_leader->sibling_list); | |
592903cd PZ |
79 | |
80 | list_add_rcu(&counter->event_entry, &ctx->event_list); | |
04289bb9 IM |
81 | } |
82 | ||
83 | static void | |
84 | list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) | |
85 | { | |
86 | struct perf_counter *sibling, *tmp; | |
87 | ||
88 | list_del_init(&counter->list_entry); | |
592903cd | 89 | list_del_rcu(&counter->event_entry); |
04289bb9 | 90 | |
04289bb9 IM |
91 | /* |
92 | * If this was a group counter with sibling counters then | |
93 | * upgrade the siblings to singleton counters by adding them | |
94 | * to the context list directly: | |
95 | */ | |
96 | list_for_each_entry_safe(sibling, tmp, | |
97 | &counter->sibling_list, list_entry) { | |
98 | ||
75564232 | 99 | list_move_tail(&sibling->list_entry, &ctx->counter_list); |
04289bb9 IM |
100 | sibling->group_leader = sibling; |
101 | } | |
102 | } | |
103 | ||
3b6f9e5c PM |
104 | static void |
105 | counter_sched_out(struct perf_counter *counter, | |
106 | struct perf_cpu_context *cpuctx, | |
107 | struct perf_counter_context *ctx) | |
108 | { | |
109 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) | |
110 | return; | |
111 | ||
112 | counter->state = PERF_COUNTER_STATE_INACTIVE; | |
113 | counter->hw_ops->disable(counter); | |
114 | counter->oncpu = -1; | |
115 | ||
116 | if (!is_software_counter(counter)) | |
117 | cpuctx->active_oncpu--; | |
118 | ctx->nr_active--; | |
119 | if (counter->hw_event.exclusive || !cpuctx->active_oncpu) | |
120 | cpuctx->exclusive = 0; | |
121 | } | |
122 | ||
d859e29f PM |
123 | static void |
124 | group_sched_out(struct perf_counter *group_counter, | |
125 | struct perf_cpu_context *cpuctx, | |
126 | struct perf_counter_context *ctx) | |
127 | { | |
128 | struct perf_counter *counter; | |
129 | ||
130 | if (group_counter->state != PERF_COUNTER_STATE_ACTIVE) | |
131 | return; | |
132 | ||
133 | counter_sched_out(group_counter, cpuctx, ctx); | |
134 | ||
135 | /* | |
136 | * Schedule out siblings (if any): | |
137 | */ | |
138 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) | |
139 | counter_sched_out(counter, cpuctx, ctx); | |
140 | ||
141 | if (group_counter->hw_event.exclusive) | |
142 | cpuctx->exclusive = 0; | |
143 | } | |
144 | ||
0793a61d TG |
145 | /* |
146 | * Cross CPU call to remove a performance counter | |
147 | * | |
148 | * We disable the counter on the hardware level first. After that we | |
149 | * remove it from the context list. | |
150 | */ | |
04289bb9 | 151 | static void __perf_counter_remove_from_context(void *info) |
0793a61d TG |
152 | { |
153 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
154 | struct perf_counter *counter = info; | |
155 | struct perf_counter_context *ctx = counter->ctx; | |
9b51f66d | 156 | unsigned long flags; |
5c92d124 | 157 | u64 perf_flags; |
0793a61d TG |
158 | |
159 | /* | |
160 | * If this is a task context, we need to check whether it is | |
161 | * the current task context of this cpu. If not it has been | |
162 | * scheduled out before the smp call arrived. | |
163 | */ | |
164 | if (ctx->task && cpuctx->task_ctx != ctx) | |
165 | return; | |
166 | ||
aa9c4c0f IM |
167 | curr_rq_lock_irq_save(&flags); |
168 | spin_lock(&ctx->lock); | |
0793a61d | 169 | |
3b6f9e5c PM |
170 | counter_sched_out(counter, cpuctx, ctx); |
171 | ||
172 | counter->task = NULL; | |
0793a61d TG |
173 | ctx->nr_counters--; |
174 | ||
175 | /* | |
176 | * Protect the list operation against NMI by disabling the | |
177 | * counters on a global level. NOP for non NMI based counters. | |
178 | */ | |
01b2838c | 179 | perf_flags = hw_perf_save_disable(); |
04289bb9 | 180 | list_del_counter(counter, ctx); |
01b2838c | 181 | hw_perf_restore(perf_flags); |
0793a61d TG |
182 | |
183 | if (!ctx->task) { | |
184 | /* | |
185 | * Allow more per task counters with respect to the | |
186 | * reservation: | |
187 | */ | |
188 | cpuctx->max_pertask = | |
189 | min(perf_max_counters - ctx->nr_counters, | |
190 | perf_max_counters - perf_reserved_percpu); | |
191 | } | |
192 | ||
aa9c4c0f IM |
193 | spin_unlock(&ctx->lock); |
194 | curr_rq_unlock_irq_restore(&flags); | |
0793a61d TG |
195 | } |
196 | ||
197 | ||
198 | /* | |
199 | * Remove the counter from a task's (or a CPU's) list of counters. | |
200 | * | |
d859e29f | 201 | * Must be called with counter->mutex and ctx->mutex held. |
0793a61d TG |
202 | * |
203 | * CPU counters are removed with a smp call. For task counters we only | |
204 | * call when the task is on a CPU. | |
205 | */ | |
04289bb9 | 206 | static void perf_counter_remove_from_context(struct perf_counter *counter) |
0793a61d TG |
207 | { |
208 | struct perf_counter_context *ctx = counter->ctx; | |
209 | struct task_struct *task = ctx->task; | |
210 | ||
211 | if (!task) { | |
212 | /* | |
213 | * Per cpu counters are removed via an smp call and | |
214 | * the removal is always sucessful. | |
215 | */ | |
216 | smp_call_function_single(counter->cpu, | |
04289bb9 | 217 | __perf_counter_remove_from_context, |
0793a61d TG |
218 | counter, 1); |
219 | return; | |
220 | } | |
221 | ||
222 | retry: | |
04289bb9 | 223 | task_oncpu_function_call(task, __perf_counter_remove_from_context, |
0793a61d TG |
224 | counter); |
225 | ||
226 | spin_lock_irq(&ctx->lock); | |
227 | /* | |
228 | * If the context is active we need to retry the smp call. | |
229 | */ | |
04289bb9 | 230 | if (ctx->nr_active && !list_empty(&counter->list_entry)) { |
0793a61d TG |
231 | spin_unlock_irq(&ctx->lock); |
232 | goto retry; | |
233 | } | |
234 | ||
235 | /* | |
236 | * The lock prevents that this context is scheduled in so we | |
04289bb9 | 237 | * can remove the counter safely, if the call above did not |
0793a61d TG |
238 | * succeed. |
239 | */ | |
04289bb9 | 240 | if (!list_empty(&counter->list_entry)) { |
0793a61d | 241 | ctx->nr_counters--; |
04289bb9 | 242 | list_del_counter(counter, ctx); |
0793a61d TG |
243 | counter->task = NULL; |
244 | } | |
245 | spin_unlock_irq(&ctx->lock); | |
246 | } | |
247 | ||
d859e29f PM |
248 | /* |
249 | * Cross CPU call to disable a performance counter | |
250 | */ | |
251 | static void __perf_counter_disable(void *info) | |
252 | { | |
253 | struct perf_counter *counter = info; | |
254 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
255 | struct perf_counter_context *ctx = counter->ctx; | |
256 | unsigned long flags; | |
257 | ||
258 | /* | |
259 | * If this is a per-task counter, need to check whether this | |
260 | * counter's task is the current task on this cpu. | |
261 | */ | |
262 | if (ctx->task && cpuctx->task_ctx != ctx) | |
263 | return; | |
264 | ||
265 | curr_rq_lock_irq_save(&flags); | |
266 | spin_lock(&ctx->lock); | |
267 | ||
268 | /* | |
269 | * If the counter is on, turn it off. | |
270 | * If it is in error state, leave it in error state. | |
271 | */ | |
272 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { | |
273 | if (counter == counter->group_leader) | |
274 | group_sched_out(counter, cpuctx, ctx); | |
275 | else | |
276 | counter_sched_out(counter, cpuctx, ctx); | |
277 | counter->state = PERF_COUNTER_STATE_OFF; | |
278 | } | |
279 | ||
280 | spin_unlock(&ctx->lock); | |
281 | curr_rq_unlock_irq_restore(&flags); | |
282 | } | |
283 | ||
284 | /* | |
285 | * Disable a counter. | |
286 | */ | |
287 | static void perf_counter_disable(struct perf_counter *counter) | |
288 | { | |
289 | struct perf_counter_context *ctx = counter->ctx; | |
290 | struct task_struct *task = ctx->task; | |
291 | ||
292 | if (!task) { | |
293 | /* | |
294 | * Disable the counter on the cpu that it's on | |
295 | */ | |
296 | smp_call_function_single(counter->cpu, __perf_counter_disable, | |
297 | counter, 1); | |
298 | return; | |
299 | } | |
300 | ||
301 | retry: | |
302 | task_oncpu_function_call(task, __perf_counter_disable, counter); | |
303 | ||
304 | spin_lock_irq(&ctx->lock); | |
305 | /* | |
306 | * If the counter is still active, we need to retry the cross-call. | |
307 | */ | |
308 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { | |
309 | spin_unlock_irq(&ctx->lock); | |
310 | goto retry; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Since we have the lock this context can't be scheduled | |
315 | * in, so we can change the state safely. | |
316 | */ | |
317 | if (counter->state == PERF_COUNTER_STATE_INACTIVE) | |
318 | counter->state = PERF_COUNTER_STATE_OFF; | |
319 | ||
320 | spin_unlock_irq(&ctx->lock); | |
321 | } | |
322 | ||
323 | /* | |
324 | * Disable a counter and all its children. | |
325 | */ | |
326 | static void perf_counter_disable_family(struct perf_counter *counter) | |
327 | { | |
328 | struct perf_counter *child; | |
329 | ||
330 | perf_counter_disable(counter); | |
331 | ||
332 | /* | |
333 | * Lock the mutex to protect the list of children | |
334 | */ | |
335 | mutex_lock(&counter->mutex); | |
336 | list_for_each_entry(child, &counter->child_list, child_list) | |
337 | perf_counter_disable(child); | |
338 | mutex_unlock(&counter->mutex); | |
339 | } | |
340 | ||
235c7fc7 IM |
341 | static int |
342 | counter_sched_in(struct perf_counter *counter, | |
343 | struct perf_cpu_context *cpuctx, | |
344 | struct perf_counter_context *ctx, | |
345 | int cpu) | |
346 | { | |
3b6f9e5c | 347 | if (counter->state <= PERF_COUNTER_STATE_OFF) |
235c7fc7 IM |
348 | return 0; |
349 | ||
350 | counter->state = PERF_COUNTER_STATE_ACTIVE; | |
351 | counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ | |
352 | /* | |
353 | * The new state must be visible before we turn it on in the hardware: | |
354 | */ | |
355 | smp_wmb(); | |
356 | ||
357 | if (counter->hw_ops->enable(counter)) { | |
358 | counter->state = PERF_COUNTER_STATE_INACTIVE; | |
359 | counter->oncpu = -1; | |
360 | return -EAGAIN; | |
361 | } | |
362 | ||
3b6f9e5c PM |
363 | if (!is_software_counter(counter)) |
364 | cpuctx->active_oncpu++; | |
235c7fc7 IM |
365 | ctx->nr_active++; |
366 | ||
3b6f9e5c PM |
367 | if (counter->hw_event.exclusive) |
368 | cpuctx->exclusive = 1; | |
369 | ||
235c7fc7 IM |
370 | return 0; |
371 | } | |
372 | ||
3b6f9e5c PM |
373 | /* |
374 | * Return 1 for a group consisting entirely of software counters, | |
375 | * 0 if the group contains any hardware counters. | |
376 | */ | |
377 | static int is_software_only_group(struct perf_counter *leader) | |
378 | { | |
379 | struct perf_counter *counter; | |
380 | ||
381 | if (!is_software_counter(leader)) | |
382 | return 0; | |
383 | list_for_each_entry(counter, &leader->sibling_list, list_entry) | |
384 | if (!is_software_counter(counter)) | |
385 | return 0; | |
386 | return 1; | |
387 | } | |
388 | ||
389 | /* | |
390 | * Work out whether we can put this counter group on the CPU now. | |
391 | */ | |
392 | static int group_can_go_on(struct perf_counter *counter, | |
393 | struct perf_cpu_context *cpuctx, | |
394 | int can_add_hw) | |
395 | { | |
396 | /* | |
397 | * Groups consisting entirely of software counters can always go on. | |
398 | */ | |
399 | if (is_software_only_group(counter)) | |
400 | return 1; | |
401 | /* | |
402 | * If an exclusive group is already on, no other hardware | |
403 | * counters can go on. | |
404 | */ | |
405 | if (cpuctx->exclusive) | |
406 | return 0; | |
407 | /* | |
408 | * If this group is exclusive and there are already | |
409 | * counters on the CPU, it can't go on. | |
410 | */ | |
411 | if (counter->hw_event.exclusive && cpuctx->active_oncpu) | |
412 | return 0; | |
413 | /* | |
414 | * Otherwise, try to add it if all previous groups were able | |
415 | * to go on. | |
416 | */ | |
417 | return can_add_hw; | |
418 | } | |
419 | ||
0793a61d | 420 | /* |
235c7fc7 | 421 | * Cross CPU call to install and enable a performance counter |
0793a61d TG |
422 | */ |
423 | static void __perf_install_in_context(void *info) | |
424 | { | |
425 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
426 | struct perf_counter *counter = info; | |
427 | struct perf_counter_context *ctx = counter->ctx; | |
d859e29f | 428 | struct perf_counter *leader = counter->group_leader; |
0793a61d | 429 | int cpu = smp_processor_id(); |
9b51f66d | 430 | unsigned long flags; |
5c92d124 | 431 | u64 perf_flags; |
3b6f9e5c | 432 | int err; |
0793a61d TG |
433 | |
434 | /* | |
435 | * If this is a task context, we need to check whether it is | |
436 | * the current task context of this cpu. If not it has been | |
437 | * scheduled out before the smp call arrived. | |
438 | */ | |
439 | if (ctx->task && cpuctx->task_ctx != ctx) | |
440 | return; | |
441 | ||
aa9c4c0f IM |
442 | curr_rq_lock_irq_save(&flags); |
443 | spin_lock(&ctx->lock); | |
0793a61d TG |
444 | |
445 | /* | |
446 | * Protect the list operation against NMI by disabling the | |
447 | * counters on a global level. NOP for non NMI based counters. | |
448 | */ | |
01b2838c | 449 | perf_flags = hw_perf_save_disable(); |
0793a61d | 450 | |
235c7fc7 | 451 | list_add_counter(counter, ctx); |
0793a61d | 452 | ctx->nr_counters++; |
c07c99b6 | 453 | counter->prev_state = PERF_COUNTER_STATE_OFF; |
0793a61d | 454 | |
d859e29f PM |
455 | /* |
456 | * Don't put the counter on if it is disabled or if | |
457 | * it is in a group and the group isn't on. | |
458 | */ | |
459 | if (counter->state != PERF_COUNTER_STATE_INACTIVE || | |
460 | (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)) | |
461 | goto unlock; | |
462 | ||
3b6f9e5c PM |
463 | /* |
464 | * An exclusive counter can't go on if there are already active | |
465 | * hardware counters, and no hardware counter can go on if there | |
466 | * is already an exclusive counter on. | |
467 | */ | |
d859e29f | 468 | if (!group_can_go_on(counter, cpuctx, 1)) |
3b6f9e5c PM |
469 | err = -EEXIST; |
470 | else | |
471 | err = counter_sched_in(counter, cpuctx, ctx, cpu); | |
472 | ||
d859e29f PM |
473 | if (err) { |
474 | /* | |
475 | * This counter couldn't go on. If it is in a group | |
476 | * then we have to pull the whole group off. | |
477 | * If the counter group is pinned then put it in error state. | |
478 | */ | |
479 | if (leader != counter) | |
480 | group_sched_out(leader, cpuctx, ctx); | |
481 | if (leader->hw_event.pinned) | |
482 | leader->state = PERF_COUNTER_STATE_ERROR; | |
483 | } | |
0793a61d | 484 | |
3b6f9e5c | 485 | if (!err && !ctx->task && cpuctx->max_pertask) |
0793a61d TG |
486 | cpuctx->max_pertask--; |
487 | ||
d859e29f | 488 | unlock: |
235c7fc7 IM |
489 | hw_perf_restore(perf_flags); |
490 | ||
aa9c4c0f IM |
491 | spin_unlock(&ctx->lock); |
492 | curr_rq_unlock_irq_restore(&flags); | |
0793a61d TG |
493 | } |
494 | ||
495 | /* | |
496 | * Attach a performance counter to a context | |
497 | * | |
498 | * First we add the counter to the list with the hardware enable bit | |
499 | * in counter->hw_config cleared. | |
500 | * | |
501 | * If the counter is attached to a task which is on a CPU we use a smp | |
502 | * call to enable it in the task context. The task might have been | |
503 | * scheduled away, but we check this in the smp call again. | |
d859e29f PM |
504 | * |
505 | * Must be called with ctx->mutex held. | |
0793a61d TG |
506 | */ |
507 | static void | |
508 | perf_install_in_context(struct perf_counter_context *ctx, | |
509 | struct perf_counter *counter, | |
510 | int cpu) | |
511 | { | |
512 | struct task_struct *task = ctx->task; | |
513 | ||
0793a61d TG |
514 | if (!task) { |
515 | /* | |
516 | * Per cpu counters are installed via an smp call and | |
517 | * the install is always sucessful. | |
518 | */ | |
519 | smp_call_function_single(cpu, __perf_install_in_context, | |
520 | counter, 1); | |
521 | return; | |
522 | } | |
523 | ||
524 | counter->task = task; | |
525 | retry: | |
526 | task_oncpu_function_call(task, __perf_install_in_context, | |
527 | counter); | |
528 | ||
529 | spin_lock_irq(&ctx->lock); | |
530 | /* | |
0793a61d TG |
531 | * we need to retry the smp call. |
532 | */ | |
d859e29f | 533 | if (ctx->is_active && list_empty(&counter->list_entry)) { |
0793a61d TG |
534 | spin_unlock_irq(&ctx->lock); |
535 | goto retry; | |
536 | } | |
537 | ||
538 | /* | |
539 | * The lock prevents that this context is scheduled in so we | |
540 | * can add the counter safely, if it the call above did not | |
541 | * succeed. | |
542 | */ | |
04289bb9 IM |
543 | if (list_empty(&counter->list_entry)) { |
544 | list_add_counter(counter, ctx); | |
0793a61d TG |
545 | ctx->nr_counters++; |
546 | } | |
547 | spin_unlock_irq(&ctx->lock); | |
548 | } | |
549 | ||
d859e29f PM |
550 | /* |
551 | * Cross CPU call to enable a performance counter | |
552 | */ | |
553 | static void __perf_counter_enable(void *info) | |
04289bb9 | 554 | { |
d859e29f PM |
555 | struct perf_counter *counter = info; |
556 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
557 | struct perf_counter_context *ctx = counter->ctx; | |
558 | struct perf_counter *leader = counter->group_leader; | |
559 | unsigned long flags; | |
560 | int err; | |
04289bb9 | 561 | |
d859e29f PM |
562 | /* |
563 | * If this is a per-task counter, need to check whether this | |
564 | * counter's task is the current task on this cpu. | |
565 | */ | |
566 | if (ctx->task && cpuctx->task_ctx != ctx) | |
3cbed429 PM |
567 | return; |
568 | ||
d859e29f PM |
569 | curr_rq_lock_irq_save(&flags); |
570 | spin_lock(&ctx->lock); | |
571 | ||
c07c99b6 | 572 | counter->prev_state = counter->state; |
d859e29f PM |
573 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) |
574 | goto unlock; | |
575 | counter->state = PERF_COUNTER_STATE_INACTIVE; | |
04289bb9 IM |
576 | |
577 | /* | |
d859e29f PM |
578 | * If the counter is in a group and isn't the group leader, |
579 | * then don't put it on unless the group is on. | |
04289bb9 | 580 | */ |
d859e29f PM |
581 | if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE) |
582 | goto unlock; | |
3b6f9e5c | 583 | |
d859e29f PM |
584 | if (!group_can_go_on(counter, cpuctx, 1)) |
585 | err = -EEXIST; | |
586 | else | |
587 | err = counter_sched_in(counter, cpuctx, ctx, | |
588 | smp_processor_id()); | |
589 | ||
590 | if (err) { | |
591 | /* | |
592 | * If this counter can't go on and it's part of a | |
593 | * group, then the whole group has to come off. | |
594 | */ | |
595 | if (leader != counter) | |
596 | group_sched_out(leader, cpuctx, ctx); | |
597 | if (leader->hw_event.pinned) | |
598 | leader->state = PERF_COUNTER_STATE_ERROR; | |
599 | } | |
600 | ||
601 | unlock: | |
602 | spin_unlock(&ctx->lock); | |
603 | curr_rq_unlock_irq_restore(&flags); | |
604 | } | |
605 | ||
606 | /* | |
607 | * Enable a counter. | |
608 | */ | |
609 | static void perf_counter_enable(struct perf_counter *counter) | |
610 | { | |
611 | struct perf_counter_context *ctx = counter->ctx; | |
612 | struct task_struct *task = ctx->task; | |
613 | ||
614 | if (!task) { | |
615 | /* | |
616 | * Enable the counter on the cpu that it's on | |
617 | */ | |
618 | smp_call_function_single(counter->cpu, __perf_counter_enable, | |
619 | counter, 1); | |
620 | return; | |
621 | } | |
622 | ||
623 | spin_lock_irq(&ctx->lock); | |
624 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) | |
625 | goto out; | |
626 | ||
627 | /* | |
628 | * If the counter is in error state, clear that first. | |
629 | * That way, if we see the counter in error state below, we | |
630 | * know that it has gone back into error state, as distinct | |
631 | * from the task having been scheduled away before the | |
632 | * cross-call arrived. | |
633 | */ | |
634 | if (counter->state == PERF_COUNTER_STATE_ERROR) | |
635 | counter->state = PERF_COUNTER_STATE_OFF; | |
636 | ||
637 | retry: | |
638 | spin_unlock_irq(&ctx->lock); | |
639 | task_oncpu_function_call(task, __perf_counter_enable, counter); | |
640 | ||
641 | spin_lock_irq(&ctx->lock); | |
642 | ||
643 | /* | |
644 | * If the context is active and the counter is still off, | |
645 | * we need to retry the cross-call. | |
646 | */ | |
647 | if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF) | |
648 | goto retry; | |
649 | ||
650 | /* | |
651 | * Since we have the lock this context can't be scheduled | |
652 | * in, so we can change the state safely. | |
653 | */ | |
654 | if (counter->state == PERF_COUNTER_STATE_OFF) | |
655 | counter->state = PERF_COUNTER_STATE_INACTIVE; | |
656 | out: | |
657 | spin_unlock_irq(&ctx->lock); | |
658 | } | |
659 | ||
660 | /* | |
661 | * Enable a counter and all its children. | |
662 | */ | |
663 | static void perf_counter_enable_family(struct perf_counter *counter) | |
664 | { | |
665 | struct perf_counter *child; | |
666 | ||
667 | perf_counter_enable(counter); | |
668 | ||
669 | /* | |
670 | * Lock the mutex to protect the list of children | |
671 | */ | |
672 | mutex_lock(&counter->mutex); | |
673 | list_for_each_entry(child, &counter->child_list, child_list) | |
674 | perf_counter_enable(child); | |
675 | mutex_unlock(&counter->mutex); | |
04289bb9 IM |
676 | } |
677 | ||
235c7fc7 IM |
678 | void __perf_counter_sched_out(struct perf_counter_context *ctx, |
679 | struct perf_cpu_context *cpuctx) | |
680 | { | |
681 | struct perf_counter *counter; | |
3cbed429 | 682 | u64 flags; |
235c7fc7 | 683 | |
d859e29f PM |
684 | spin_lock(&ctx->lock); |
685 | ctx->is_active = 0; | |
235c7fc7 | 686 | if (likely(!ctx->nr_counters)) |
d859e29f | 687 | goto out; |
235c7fc7 | 688 | |
3cbed429 | 689 | flags = hw_perf_save_disable(); |
235c7fc7 IM |
690 | if (ctx->nr_active) { |
691 | list_for_each_entry(counter, &ctx->counter_list, list_entry) | |
692 | group_sched_out(counter, cpuctx, ctx); | |
693 | } | |
3cbed429 | 694 | hw_perf_restore(flags); |
d859e29f | 695 | out: |
235c7fc7 IM |
696 | spin_unlock(&ctx->lock); |
697 | } | |
698 | ||
0793a61d TG |
699 | /* |
700 | * Called from scheduler to remove the counters of the current task, | |
701 | * with interrupts disabled. | |
702 | * | |
703 | * We stop each counter and update the counter value in counter->count. | |
704 | * | |
7671581f | 705 | * This does not protect us against NMI, but disable() |
0793a61d TG |
706 | * sets the disabled bit in the control field of counter _before_ |
707 | * accessing the counter control register. If a NMI hits, then it will | |
708 | * not restart the counter. | |
709 | */ | |
710 | void perf_counter_task_sched_out(struct task_struct *task, int cpu) | |
711 | { | |
712 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); | |
713 | struct perf_counter_context *ctx = &task->perf_counter_ctx; | |
4a0deca6 | 714 | struct pt_regs *regs; |
0793a61d TG |
715 | |
716 | if (likely(!cpuctx->task_ctx)) | |
717 | return; | |
718 | ||
4a0deca6 PZ |
719 | regs = task_pt_regs(task); |
720 | perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES, 1, 1, regs); | |
235c7fc7 IM |
721 | __perf_counter_sched_out(ctx, cpuctx); |
722 | ||
0793a61d TG |
723 | cpuctx->task_ctx = NULL; |
724 | } | |
725 | ||
235c7fc7 | 726 | static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx) |
04289bb9 | 727 | { |
235c7fc7 | 728 | __perf_counter_sched_out(&cpuctx->ctx, cpuctx); |
04289bb9 IM |
729 | } |
730 | ||
7995888f | 731 | static int |
04289bb9 IM |
732 | group_sched_in(struct perf_counter *group_counter, |
733 | struct perf_cpu_context *cpuctx, | |
734 | struct perf_counter_context *ctx, | |
735 | int cpu) | |
736 | { | |
95cdd2e7 | 737 | struct perf_counter *counter, *partial_group; |
3cbed429 PM |
738 | int ret; |
739 | ||
740 | if (group_counter->state == PERF_COUNTER_STATE_OFF) | |
741 | return 0; | |
742 | ||
743 | ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu); | |
744 | if (ret) | |
745 | return ret < 0 ? ret : 0; | |
04289bb9 | 746 | |
c07c99b6 | 747 | group_counter->prev_state = group_counter->state; |
95cdd2e7 IM |
748 | if (counter_sched_in(group_counter, cpuctx, ctx, cpu)) |
749 | return -EAGAIN; | |
04289bb9 IM |
750 | |
751 | /* | |
752 | * Schedule in siblings as one group (if any): | |
753 | */ | |
7995888f | 754 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { |
c07c99b6 | 755 | counter->prev_state = counter->state; |
95cdd2e7 IM |
756 | if (counter_sched_in(counter, cpuctx, ctx, cpu)) { |
757 | partial_group = counter; | |
758 | goto group_error; | |
759 | } | |
95cdd2e7 IM |
760 | } |
761 | ||
3cbed429 | 762 | return 0; |
95cdd2e7 IM |
763 | |
764 | group_error: | |
765 | /* | |
766 | * Groups can be scheduled in as one unit only, so undo any | |
767 | * partial group before returning: | |
768 | */ | |
769 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { | |
770 | if (counter == partial_group) | |
771 | break; | |
772 | counter_sched_out(counter, cpuctx, ctx); | |
7995888f | 773 | } |
95cdd2e7 | 774 | counter_sched_out(group_counter, cpuctx, ctx); |
7995888f | 775 | |
95cdd2e7 | 776 | return -EAGAIN; |
04289bb9 IM |
777 | } |
778 | ||
235c7fc7 IM |
779 | static void |
780 | __perf_counter_sched_in(struct perf_counter_context *ctx, | |
781 | struct perf_cpu_context *cpuctx, int cpu) | |
0793a61d | 782 | { |
0793a61d | 783 | struct perf_counter *counter; |
3cbed429 | 784 | u64 flags; |
dd0e6ba2 | 785 | int can_add_hw = 1; |
0793a61d | 786 | |
d859e29f PM |
787 | spin_lock(&ctx->lock); |
788 | ctx->is_active = 1; | |
0793a61d | 789 | if (likely(!ctx->nr_counters)) |
d859e29f | 790 | goto out; |
0793a61d | 791 | |
3cbed429 | 792 | flags = hw_perf_save_disable(); |
3b6f9e5c PM |
793 | |
794 | /* | |
795 | * First go through the list and put on any pinned groups | |
796 | * in order to give them the best chance of going on. | |
797 | */ | |
798 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { | |
799 | if (counter->state <= PERF_COUNTER_STATE_OFF || | |
800 | !counter->hw_event.pinned) | |
801 | continue; | |
802 | if (counter->cpu != -1 && counter->cpu != cpu) | |
803 | continue; | |
804 | ||
805 | if (group_can_go_on(counter, cpuctx, 1)) | |
806 | group_sched_in(counter, cpuctx, ctx, cpu); | |
807 | ||
808 | /* | |
809 | * If this pinned group hasn't been scheduled, | |
810 | * put it in error state. | |
811 | */ | |
812 | if (counter->state == PERF_COUNTER_STATE_INACTIVE) | |
813 | counter->state = PERF_COUNTER_STATE_ERROR; | |
814 | } | |
815 | ||
04289bb9 | 816 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
3b6f9e5c PM |
817 | /* |
818 | * Ignore counters in OFF or ERROR state, and | |
819 | * ignore pinned counters since we did them already. | |
820 | */ | |
821 | if (counter->state <= PERF_COUNTER_STATE_OFF || | |
822 | counter->hw_event.pinned) | |
823 | continue; | |
824 | ||
04289bb9 IM |
825 | /* |
826 | * Listen to the 'cpu' scheduling filter constraint | |
827 | * of counters: | |
828 | */ | |
0793a61d TG |
829 | if (counter->cpu != -1 && counter->cpu != cpu) |
830 | continue; | |
831 | ||
3b6f9e5c | 832 | if (group_can_go_on(counter, cpuctx, can_add_hw)) { |
dd0e6ba2 PM |
833 | if (group_sched_in(counter, cpuctx, ctx, cpu)) |
834 | can_add_hw = 0; | |
3b6f9e5c | 835 | } |
0793a61d | 836 | } |
3cbed429 | 837 | hw_perf_restore(flags); |
d859e29f | 838 | out: |
0793a61d | 839 | spin_unlock(&ctx->lock); |
235c7fc7 IM |
840 | } |
841 | ||
842 | /* | |
843 | * Called from scheduler to add the counters of the current task | |
844 | * with interrupts disabled. | |
845 | * | |
846 | * We restore the counter value and then enable it. | |
847 | * | |
848 | * This does not protect us against NMI, but enable() | |
849 | * sets the enabled bit in the control field of counter _before_ | |
850 | * accessing the counter control register. If a NMI hits, then it will | |
851 | * keep the counter running. | |
852 | */ | |
853 | void perf_counter_task_sched_in(struct task_struct *task, int cpu) | |
854 | { | |
855 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); | |
856 | struct perf_counter_context *ctx = &task->perf_counter_ctx; | |
04289bb9 | 857 | |
235c7fc7 | 858 | __perf_counter_sched_in(ctx, cpuctx, cpu); |
0793a61d TG |
859 | cpuctx->task_ctx = ctx; |
860 | } | |
861 | ||
235c7fc7 IM |
862 | static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) |
863 | { | |
864 | struct perf_counter_context *ctx = &cpuctx->ctx; | |
865 | ||
866 | __perf_counter_sched_in(ctx, cpuctx, cpu); | |
867 | } | |
868 | ||
1d1c7ddb IM |
869 | int perf_counter_task_disable(void) |
870 | { | |
871 | struct task_struct *curr = current; | |
872 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
873 | struct perf_counter *counter; | |
aa9c4c0f | 874 | unsigned long flags; |
1d1c7ddb IM |
875 | u64 perf_flags; |
876 | int cpu; | |
877 | ||
878 | if (likely(!ctx->nr_counters)) | |
879 | return 0; | |
880 | ||
aa9c4c0f | 881 | curr_rq_lock_irq_save(&flags); |
1d1c7ddb IM |
882 | cpu = smp_processor_id(); |
883 | ||
aa9c4c0f IM |
884 | /* force the update of the task clock: */ |
885 | __task_delta_exec(curr, 1); | |
886 | ||
1d1c7ddb IM |
887 | perf_counter_task_sched_out(curr, cpu); |
888 | ||
889 | spin_lock(&ctx->lock); | |
890 | ||
891 | /* | |
892 | * Disable all the counters: | |
893 | */ | |
894 | perf_flags = hw_perf_save_disable(); | |
895 | ||
3b6f9e5c PM |
896 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
897 | if (counter->state != PERF_COUNTER_STATE_ERROR) | |
898 | counter->state = PERF_COUNTER_STATE_OFF; | |
899 | } | |
9b51f66d | 900 | |
1d1c7ddb IM |
901 | hw_perf_restore(perf_flags); |
902 | ||
903 | spin_unlock(&ctx->lock); | |
904 | ||
aa9c4c0f | 905 | curr_rq_unlock_irq_restore(&flags); |
1d1c7ddb IM |
906 | |
907 | return 0; | |
908 | } | |
909 | ||
910 | int perf_counter_task_enable(void) | |
911 | { | |
912 | struct task_struct *curr = current; | |
913 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
914 | struct perf_counter *counter; | |
aa9c4c0f | 915 | unsigned long flags; |
1d1c7ddb IM |
916 | u64 perf_flags; |
917 | int cpu; | |
918 | ||
919 | if (likely(!ctx->nr_counters)) | |
920 | return 0; | |
921 | ||
aa9c4c0f | 922 | curr_rq_lock_irq_save(&flags); |
1d1c7ddb IM |
923 | cpu = smp_processor_id(); |
924 | ||
aa9c4c0f IM |
925 | /* force the update of the task clock: */ |
926 | __task_delta_exec(curr, 1); | |
927 | ||
235c7fc7 IM |
928 | perf_counter_task_sched_out(curr, cpu); |
929 | ||
1d1c7ddb IM |
930 | spin_lock(&ctx->lock); |
931 | ||
932 | /* | |
933 | * Disable all the counters: | |
934 | */ | |
935 | perf_flags = hw_perf_save_disable(); | |
936 | ||
937 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { | |
3b6f9e5c | 938 | if (counter->state > PERF_COUNTER_STATE_OFF) |
1d1c7ddb | 939 | continue; |
6a930700 | 940 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
aa9c4c0f | 941 | counter->hw_event.disabled = 0; |
1d1c7ddb IM |
942 | } |
943 | hw_perf_restore(perf_flags); | |
944 | ||
945 | spin_unlock(&ctx->lock); | |
946 | ||
947 | perf_counter_task_sched_in(curr, cpu); | |
948 | ||
aa9c4c0f | 949 | curr_rq_unlock_irq_restore(&flags); |
1d1c7ddb IM |
950 | |
951 | return 0; | |
952 | } | |
953 | ||
235c7fc7 IM |
954 | /* |
955 | * Round-robin a context's counters: | |
956 | */ | |
957 | static void rotate_ctx(struct perf_counter_context *ctx) | |
0793a61d | 958 | { |
0793a61d | 959 | struct perf_counter *counter; |
5c92d124 | 960 | u64 perf_flags; |
0793a61d | 961 | |
235c7fc7 | 962 | if (!ctx->nr_counters) |
0793a61d TG |
963 | return; |
964 | ||
0793a61d | 965 | spin_lock(&ctx->lock); |
0793a61d | 966 | /* |
04289bb9 | 967 | * Rotate the first entry last (works just fine for group counters too): |
0793a61d | 968 | */ |
01b2838c | 969 | perf_flags = hw_perf_save_disable(); |
04289bb9 | 970 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
75564232 | 971 | list_move_tail(&counter->list_entry, &ctx->counter_list); |
0793a61d TG |
972 | break; |
973 | } | |
01b2838c | 974 | hw_perf_restore(perf_flags); |
0793a61d TG |
975 | |
976 | spin_unlock(&ctx->lock); | |
235c7fc7 IM |
977 | } |
978 | ||
979 | void perf_counter_task_tick(struct task_struct *curr, int cpu) | |
980 | { | |
981 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); | |
982 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
983 | const int rotate_percpu = 0; | |
984 | ||
985 | if (rotate_percpu) | |
986 | perf_counter_cpu_sched_out(cpuctx); | |
987 | perf_counter_task_sched_out(curr, cpu); | |
0793a61d | 988 | |
235c7fc7 IM |
989 | if (rotate_percpu) |
990 | rotate_ctx(&cpuctx->ctx); | |
991 | rotate_ctx(ctx); | |
992 | ||
993 | if (rotate_percpu) | |
994 | perf_counter_cpu_sched_in(cpuctx, cpu); | |
0793a61d TG |
995 | perf_counter_task_sched_in(curr, cpu); |
996 | } | |
997 | ||
0793a61d TG |
998 | /* |
999 | * Cross CPU call to read the hardware counter | |
1000 | */ | |
7671581f | 1001 | static void __read(void *info) |
0793a61d | 1002 | { |
621a01ea | 1003 | struct perf_counter *counter = info; |
aa9c4c0f | 1004 | unsigned long flags; |
621a01ea | 1005 | |
aa9c4c0f | 1006 | curr_rq_lock_irq_save(&flags); |
7671581f | 1007 | counter->hw_ops->read(counter); |
aa9c4c0f | 1008 | curr_rq_unlock_irq_restore(&flags); |
0793a61d TG |
1009 | } |
1010 | ||
04289bb9 | 1011 | static u64 perf_counter_read(struct perf_counter *counter) |
0793a61d TG |
1012 | { |
1013 | /* | |
1014 | * If counter is enabled and currently active on a CPU, update the | |
1015 | * value in the counter structure: | |
1016 | */ | |
6a930700 | 1017 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { |
0793a61d | 1018 | smp_call_function_single(counter->oncpu, |
7671581f | 1019 | __read, counter, 1); |
0793a61d TG |
1020 | } |
1021 | ||
ee06094f | 1022 | return atomic64_read(&counter->count); |
0793a61d TG |
1023 | } |
1024 | ||
1025 | /* | |
1026 | * Cross CPU call to switch performance data pointers | |
1027 | */ | |
1028 | static void __perf_switch_irq_data(void *info) | |
1029 | { | |
1030 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
1031 | struct perf_counter *counter = info; | |
1032 | struct perf_counter_context *ctx = counter->ctx; | |
1033 | struct perf_data *oldirqdata = counter->irqdata; | |
1034 | ||
1035 | /* | |
1036 | * If this is a task context, we need to check whether it is | |
1037 | * the current task context of this cpu. If not it has been | |
1038 | * scheduled out before the smp call arrived. | |
1039 | */ | |
1040 | if (ctx->task) { | |
1041 | if (cpuctx->task_ctx != ctx) | |
1042 | return; | |
1043 | spin_lock(&ctx->lock); | |
1044 | } | |
1045 | ||
1046 | /* Change the pointer NMI safe */ | |
1047 | atomic_long_set((atomic_long_t *)&counter->irqdata, | |
1048 | (unsigned long) counter->usrdata); | |
1049 | counter->usrdata = oldirqdata; | |
1050 | ||
1051 | if (ctx->task) | |
1052 | spin_unlock(&ctx->lock); | |
1053 | } | |
1054 | ||
1055 | static struct perf_data *perf_switch_irq_data(struct perf_counter *counter) | |
1056 | { | |
1057 | struct perf_counter_context *ctx = counter->ctx; | |
1058 | struct perf_data *oldirqdata = counter->irqdata; | |
1059 | struct task_struct *task = ctx->task; | |
1060 | ||
1061 | if (!task) { | |
1062 | smp_call_function_single(counter->cpu, | |
1063 | __perf_switch_irq_data, | |
1064 | counter, 1); | |
1065 | return counter->usrdata; | |
1066 | } | |
1067 | ||
1068 | retry: | |
1069 | spin_lock_irq(&ctx->lock); | |
6a930700 | 1070 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) { |
0793a61d TG |
1071 | counter->irqdata = counter->usrdata; |
1072 | counter->usrdata = oldirqdata; | |
1073 | spin_unlock_irq(&ctx->lock); | |
1074 | return oldirqdata; | |
1075 | } | |
1076 | spin_unlock_irq(&ctx->lock); | |
1077 | task_oncpu_function_call(task, __perf_switch_irq_data, counter); | |
1078 | /* Might have failed, because task was scheduled out */ | |
1079 | if (counter->irqdata == oldirqdata) | |
1080 | goto retry; | |
1081 | ||
1082 | return counter->usrdata; | |
1083 | } | |
1084 | ||
1085 | static void put_context(struct perf_counter_context *ctx) | |
1086 | { | |
1087 | if (ctx->task) | |
1088 | put_task_struct(ctx->task); | |
1089 | } | |
1090 | ||
1091 | static struct perf_counter_context *find_get_context(pid_t pid, int cpu) | |
1092 | { | |
1093 | struct perf_cpu_context *cpuctx; | |
1094 | struct perf_counter_context *ctx; | |
1095 | struct task_struct *task; | |
1096 | ||
1097 | /* | |
1098 | * If cpu is not a wildcard then this is a percpu counter: | |
1099 | */ | |
1100 | if (cpu != -1) { | |
1101 | /* Must be root to operate on a CPU counter: */ | |
1102 | if (!capable(CAP_SYS_ADMIN)) | |
1103 | return ERR_PTR(-EACCES); | |
1104 | ||
1105 | if (cpu < 0 || cpu > num_possible_cpus()) | |
1106 | return ERR_PTR(-EINVAL); | |
1107 | ||
1108 | /* | |
1109 | * We could be clever and allow to attach a counter to an | |
1110 | * offline CPU and activate it when the CPU comes up, but | |
1111 | * that's for later. | |
1112 | */ | |
1113 | if (!cpu_isset(cpu, cpu_online_map)) | |
1114 | return ERR_PTR(-ENODEV); | |
1115 | ||
1116 | cpuctx = &per_cpu(perf_cpu_context, cpu); | |
1117 | ctx = &cpuctx->ctx; | |
1118 | ||
0793a61d TG |
1119 | return ctx; |
1120 | } | |
1121 | ||
1122 | rcu_read_lock(); | |
1123 | if (!pid) | |
1124 | task = current; | |
1125 | else | |
1126 | task = find_task_by_vpid(pid); | |
1127 | if (task) | |
1128 | get_task_struct(task); | |
1129 | rcu_read_unlock(); | |
1130 | ||
1131 | if (!task) | |
1132 | return ERR_PTR(-ESRCH); | |
1133 | ||
1134 | ctx = &task->perf_counter_ctx; | |
1135 | ctx->task = task; | |
1136 | ||
1137 | /* Reuse ptrace permission checks for now. */ | |
1138 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) { | |
1139 | put_context(ctx); | |
1140 | return ERR_PTR(-EACCES); | |
1141 | } | |
1142 | ||
1143 | return ctx; | |
1144 | } | |
1145 | ||
592903cd PZ |
1146 | static void free_counter_rcu(struct rcu_head *head) |
1147 | { | |
1148 | struct perf_counter *counter; | |
1149 | ||
1150 | counter = container_of(head, struct perf_counter, rcu_head); | |
1151 | kfree(counter); | |
1152 | } | |
1153 | ||
f1600952 PZ |
1154 | static void free_counter(struct perf_counter *counter) |
1155 | { | |
e077df4f PZ |
1156 | if (counter->destroy) |
1157 | counter->destroy(counter); | |
1158 | ||
f1600952 PZ |
1159 | call_rcu(&counter->rcu_head, free_counter_rcu); |
1160 | } | |
1161 | ||
0793a61d TG |
1162 | /* |
1163 | * Called when the last reference to the file is gone. | |
1164 | */ | |
1165 | static int perf_release(struct inode *inode, struct file *file) | |
1166 | { | |
1167 | struct perf_counter *counter = file->private_data; | |
1168 | struct perf_counter_context *ctx = counter->ctx; | |
1169 | ||
1170 | file->private_data = NULL; | |
1171 | ||
d859e29f | 1172 | mutex_lock(&ctx->mutex); |
0793a61d TG |
1173 | mutex_lock(&counter->mutex); |
1174 | ||
04289bb9 | 1175 | perf_counter_remove_from_context(counter); |
0793a61d TG |
1176 | |
1177 | mutex_unlock(&counter->mutex); | |
d859e29f | 1178 | mutex_unlock(&ctx->mutex); |
0793a61d | 1179 | |
f1600952 | 1180 | free_counter(counter); |
5af75917 | 1181 | put_context(ctx); |
0793a61d TG |
1182 | |
1183 | return 0; | |
1184 | } | |
1185 | ||
1186 | /* | |
1187 | * Read the performance counter - simple non blocking version for now | |
1188 | */ | |
1189 | static ssize_t | |
1190 | perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) | |
1191 | { | |
1192 | u64 cntval; | |
1193 | ||
1194 | if (count != sizeof(cntval)) | |
1195 | return -EINVAL; | |
1196 | ||
3b6f9e5c PM |
1197 | /* |
1198 | * Return end-of-file for a read on a counter that is in | |
1199 | * error state (i.e. because it was pinned but it couldn't be | |
1200 | * scheduled on to the CPU at some point). | |
1201 | */ | |
1202 | if (counter->state == PERF_COUNTER_STATE_ERROR) | |
1203 | return 0; | |
1204 | ||
0793a61d | 1205 | mutex_lock(&counter->mutex); |
04289bb9 | 1206 | cntval = perf_counter_read(counter); |
0793a61d TG |
1207 | mutex_unlock(&counter->mutex); |
1208 | ||
1209 | return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval); | |
1210 | } | |
1211 | ||
1212 | static ssize_t | |
1213 | perf_copy_usrdata(struct perf_data *usrdata, char __user *buf, size_t count) | |
1214 | { | |
1215 | if (!usrdata->len) | |
1216 | return 0; | |
1217 | ||
1218 | count = min(count, (size_t)usrdata->len); | |
1219 | if (copy_to_user(buf, usrdata->data + usrdata->rd_idx, count)) | |
1220 | return -EFAULT; | |
1221 | ||
1222 | /* Adjust the counters */ | |
1223 | usrdata->len -= count; | |
1224 | if (!usrdata->len) | |
1225 | usrdata->rd_idx = 0; | |
1226 | else | |
1227 | usrdata->rd_idx += count; | |
1228 | ||
1229 | return count; | |
1230 | } | |
1231 | ||
1232 | static ssize_t | |
1233 | perf_read_irq_data(struct perf_counter *counter, | |
1234 | char __user *buf, | |
1235 | size_t count, | |
1236 | int nonblocking) | |
1237 | { | |
1238 | struct perf_data *irqdata, *usrdata; | |
1239 | DECLARE_WAITQUEUE(wait, current); | |
3b6f9e5c | 1240 | ssize_t res, res2; |
0793a61d TG |
1241 | |
1242 | irqdata = counter->irqdata; | |
1243 | usrdata = counter->usrdata; | |
1244 | ||
1245 | if (usrdata->len + irqdata->len >= count) | |
1246 | goto read_pending; | |
1247 | ||
1248 | if (nonblocking) | |
1249 | return -EAGAIN; | |
1250 | ||
1251 | spin_lock_irq(&counter->waitq.lock); | |
1252 | __add_wait_queue(&counter->waitq, &wait); | |
1253 | for (;;) { | |
1254 | set_current_state(TASK_INTERRUPTIBLE); | |
1255 | if (usrdata->len + irqdata->len >= count) | |
1256 | break; | |
1257 | ||
1258 | if (signal_pending(current)) | |
1259 | break; | |
1260 | ||
3b6f9e5c PM |
1261 | if (counter->state == PERF_COUNTER_STATE_ERROR) |
1262 | break; | |
1263 | ||
0793a61d TG |
1264 | spin_unlock_irq(&counter->waitq.lock); |
1265 | schedule(); | |
1266 | spin_lock_irq(&counter->waitq.lock); | |
1267 | } | |
1268 | __remove_wait_queue(&counter->waitq, &wait); | |
1269 | __set_current_state(TASK_RUNNING); | |
1270 | spin_unlock_irq(&counter->waitq.lock); | |
1271 | ||
3b6f9e5c PM |
1272 | if (usrdata->len + irqdata->len < count && |
1273 | counter->state != PERF_COUNTER_STATE_ERROR) | |
0793a61d TG |
1274 | return -ERESTARTSYS; |
1275 | read_pending: | |
1276 | mutex_lock(&counter->mutex); | |
1277 | ||
1278 | /* Drain pending data first: */ | |
1279 | res = perf_copy_usrdata(usrdata, buf, count); | |
1280 | if (res < 0 || res == count) | |
1281 | goto out; | |
1282 | ||
1283 | /* Switch irq buffer: */ | |
1284 | usrdata = perf_switch_irq_data(counter); | |
3b6f9e5c PM |
1285 | res2 = perf_copy_usrdata(usrdata, buf + res, count - res); |
1286 | if (res2 < 0) { | |
0793a61d TG |
1287 | if (!res) |
1288 | res = -EFAULT; | |
1289 | } else { | |
3b6f9e5c | 1290 | res += res2; |
0793a61d TG |
1291 | } |
1292 | out: | |
1293 | mutex_unlock(&counter->mutex); | |
1294 | ||
1295 | return res; | |
1296 | } | |
1297 | ||
1298 | static ssize_t | |
1299 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
1300 | { | |
1301 | struct perf_counter *counter = file->private_data; | |
1302 | ||
9f66a381 | 1303 | switch (counter->hw_event.record_type) { |
0793a61d TG |
1304 | case PERF_RECORD_SIMPLE: |
1305 | return perf_read_hw(counter, buf, count); | |
1306 | ||
1307 | case PERF_RECORD_IRQ: | |
1308 | case PERF_RECORD_GROUP: | |
1309 | return perf_read_irq_data(counter, buf, count, | |
1310 | file->f_flags & O_NONBLOCK); | |
1311 | } | |
1312 | return -EINVAL; | |
1313 | } | |
1314 | ||
1315 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
1316 | { | |
1317 | struct perf_counter *counter = file->private_data; | |
1318 | unsigned int events = 0; | |
1319 | unsigned long flags; | |
1320 | ||
1321 | poll_wait(file, &counter->waitq, wait); | |
1322 | ||
1323 | spin_lock_irqsave(&counter->waitq.lock, flags); | |
1324 | if (counter->usrdata->len || counter->irqdata->len) | |
1325 | events |= POLLIN; | |
1326 | spin_unlock_irqrestore(&counter->waitq.lock, flags); | |
1327 | ||
1328 | return events; | |
1329 | } | |
1330 | ||
d859e29f PM |
1331 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1332 | { | |
1333 | struct perf_counter *counter = file->private_data; | |
1334 | int err = 0; | |
1335 | ||
1336 | switch (cmd) { | |
1337 | case PERF_COUNTER_IOC_ENABLE: | |
1338 | perf_counter_enable_family(counter); | |
1339 | break; | |
1340 | case PERF_COUNTER_IOC_DISABLE: | |
1341 | perf_counter_disable_family(counter); | |
1342 | break; | |
1343 | default: | |
1344 | err = -ENOTTY; | |
1345 | } | |
1346 | return err; | |
1347 | } | |
1348 | ||
0793a61d TG |
1349 | static const struct file_operations perf_fops = { |
1350 | .release = perf_release, | |
1351 | .read = perf_read, | |
1352 | .poll = perf_poll, | |
d859e29f PM |
1353 | .unlocked_ioctl = perf_ioctl, |
1354 | .compat_ioctl = perf_ioctl, | |
0793a61d TG |
1355 | }; |
1356 | ||
0322cd6e PZ |
1357 | /* |
1358 | * Output | |
1359 | */ | |
1360 | ||
1361 | static void perf_counter_store_irq(struct perf_counter *counter, u64 data) | |
1362 | { | |
1363 | struct perf_data *irqdata = counter->irqdata; | |
1364 | ||
1365 | if (irqdata->len > PERF_DATA_BUFLEN - sizeof(u64)) { | |
1366 | irqdata->overrun++; | |
1367 | } else { | |
1368 | u64 *p = (u64 *) &irqdata->data[irqdata->len]; | |
1369 | ||
1370 | *p = data; | |
1371 | irqdata->len += sizeof(u64); | |
1372 | } | |
1373 | } | |
1374 | ||
1375 | static void perf_counter_handle_group(struct perf_counter *counter) | |
1376 | { | |
1377 | struct perf_counter *leader, *sub; | |
1378 | ||
1379 | leader = counter->group_leader; | |
1380 | list_for_each_entry(sub, &leader->sibling_list, list_entry) { | |
1381 | if (sub != counter) | |
1382 | sub->hw_ops->read(sub); | |
f4a2deb4 | 1383 | perf_counter_store_irq(counter, sub->hw_event.config); |
0322cd6e PZ |
1384 | perf_counter_store_irq(counter, atomic64_read(&sub->count)); |
1385 | } | |
1386 | } | |
1387 | ||
1388 | void perf_counter_output(struct perf_counter *counter, | |
1389 | int nmi, struct pt_regs *regs) | |
1390 | { | |
1391 | switch (counter->hw_event.record_type) { | |
1392 | case PERF_RECORD_SIMPLE: | |
1393 | return; | |
1394 | ||
1395 | case PERF_RECORD_IRQ: | |
1396 | perf_counter_store_irq(counter, instruction_pointer(regs)); | |
1397 | break; | |
1398 | ||
1399 | case PERF_RECORD_GROUP: | |
1400 | perf_counter_handle_group(counter); | |
1401 | break; | |
1402 | } | |
1403 | ||
1404 | if (nmi) { | |
1405 | counter->wakeup_pending = 1; | |
1406 | set_perf_counter_pending(); | |
1407 | } else | |
1408 | wake_up(&counter->waitq); | |
1409 | } | |
1410 | ||
15dbf27c PZ |
1411 | /* |
1412 | * Generic software counter infrastructure | |
1413 | */ | |
1414 | ||
1415 | static void perf_swcounter_update(struct perf_counter *counter) | |
1416 | { | |
1417 | struct hw_perf_counter *hwc = &counter->hw; | |
1418 | u64 prev, now; | |
1419 | s64 delta; | |
1420 | ||
1421 | again: | |
1422 | prev = atomic64_read(&hwc->prev_count); | |
1423 | now = atomic64_read(&hwc->count); | |
1424 | if (atomic64_cmpxchg(&hwc->prev_count, prev, now) != prev) | |
1425 | goto again; | |
1426 | ||
1427 | delta = now - prev; | |
1428 | ||
1429 | atomic64_add(delta, &counter->count); | |
1430 | atomic64_sub(delta, &hwc->period_left); | |
1431 | } | |
1432 | ||
1433 | static void perf_swcounter_set_period(struct perf_counter *counter) | |
1434 | { | |
1435 | struct hw_perf_counter *hwc = &counter->hw; | |
1436 | s64 left = atomic64_read(&hwc->period_left); | |
1437 | s64 period = hwc->irq_period; | |
1438 | ||
1439 | if (unlikely(left <= -period)) { | |
1440 | left = period; | |
1441 | atomic64_set(&hwc->period_left, left); | |
1442 | } | |
1443 | ||
1444 | if (unlikely(left <= 0)) { | |
1445 | left += period; | |
1446 | atomic64_add(period, &hwc->period_left); | |
1447 | } | |
1448 | ||
1449 | atomic64_set(&hwc->prev_count, -left); | |
1450 | atomic64_set(&hwc->count, -left); | |
1451 | } | |
1452 | ||
d6d020e9 PZ |
1453 | static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) |
1454 | { | |
1455 | struct perf_counter *counter; | |
1456 | struct pt_regs *regs; | |
1457 | ||
1458 | counter = container_of(hrtimer, struct perf_counter, hw.hrtimer); | |
1459 | counter->hw_ops->read(counter); | |
1460 | ||
1461 | regs = get_irq_regs(); | |
1462 | /* | |
1463 | * In case we exclude kernel IPs or are somehow not in interrupt | |
1464 | * context, provide the next best thing, the user IP. | |
1465 | */ | |
1466 | if ((counter->hw_event.exclude_kernel || !regs) && | |
1467 | !counter->hw_event.exclude_user) | |
1468 | regs = task_pt_regs(current); | |
1469 | ||
1470 | if (regs) | |
0322cd6e | 1471 | perf_counter_output(counter, 0, regs); |
d6d020e9 PZ |
1472 | |
1473 | hrtimer_forward_now(hrtimer, ns_to_ktime(counter->hw.irq_period)); | |
1474 | ||
1475 | return HRTIMER_RESTART; | |
1476 | } | |
1477 | ||
1478 | static void perf_swcounter_overflow(struct perf_counter *counter, | |
1479 | int nmi, struct pt_regs *regs) | |
1480 | { | |
b8e83514 PZ |
1481 | perf_swcounter_update(counter); |
1482 | perf_swcounter_set_period(counter); | |
0322cd6e | 1483 | perf_counter_output(counter, nmi, regs); |
d6d020e9 PZ |
1484 | } |
1485 | ||
15dbf27c | 1486 | static int perf_swcounter_match(struct perf_counter *counter, |
b8e83514 PZ |
1487 | enum perf_event_types type, |
1488 | u32 event, struct pt_regs *regs) | |
15dbf27c PZ |
1489 | { |
1490 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) | |
1491 | return 0; | |
1492 | ||
f4a2deb4 | 1493 | if (perf_event_raw(&counter->hw_event)) |
b8e83514 PZ |
1494 | return 0; |
1495 | ||
f4a2deb4 | 1496 | if (perf_event_type(&counter->hw_event) != type) |
15dbf27c PZ |
1497 | return 0; |
1498 | ||
f4a2deb4 | 1499 | if (perf_event_id(&counter->hw_event) != event) |
15dbf27c PZ |
1500 | return 0; |
1501 | ||
1502 | if (counter->hw_event.exclude_user && user_mode(regs)) | |
1503 | return 0; | |
1504 | ||
1505 | if (counter->hw_event.exclude_kernel && !user_mode(regs)) | |
1506 | return 0; | |
1507 | ||
1508 | return 1; | |
1509 | } | |
1510 | ||
d6d020e9 PZ |
1511 | static void perf_swcounter_add(struct perf_counter *counter, u64 nr, |
1512 | int nmi, struct pt_regs *regs) | |
1513 | { | |
1514 | int neg = atomic64_add_negative(nr, &counter->hw.count); | |
1515 | if (counter->hw.irq_period && !neg) | |
1516 | perf_swcounter_overflow(counter, nmi, regs); | |
1517 | } | |
1518 | ||
15dbf27c | 1519 | static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, |
b8e83514 PZ |
1520 | enum perf_event_types type, u32 event, |
1521 | u64 nr, int nmi, struct pt_regs *regs) | |
15dbf27c PZ |
1522 | { |
1523 | struct perf_counter *counter; | |
15dbf27c | 1524 | |
01ef09d9 | 1525 | if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) |
15dbf27c PZ |
1526 | return; |
1527 | ||
592903cd PZ |
1528 | rcu_read_lock(); |
1529 | list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { | |
b8e83514 | 1530 | if (perf_swcounter_match(counter, type, event, regs)) |
d6d020e9 | 1531 | perf_swcounter_add(counter, nr, nmi, regs); |
15dbf27c | 1532 | } |
592903cd | 1533 | rcu_read_unlock(); |
15dbf27c PZ |
1534 | } |
1535 | ||
96f6d444 PZ |
1536 | static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx) |
1537 | { | |
1538 | if (in_nmi()) | |
1539 | return &cpuctx->recursion[3]; | |
1540 | ||
1541 | if (in_irq()) | |
1542 | return &cpuctx->recursion[2]; | |
1543 | ||
1544 | if (in_softirq()) | |
1545 | return &cpuctx->recursion[1]; | |
1546 | ||
1547 | return &cpuctx->recursion[0]; | |
1548 | } | |
1549 | ||
b8e83514 PZ |
1550 | static void __perf_swcounter_event(enum perf_event_types type, u32 event, |
1551 | u64 nr, int nmi, struct pt_regs *regs) | |
15dbf27c PZ |
1552 | { |
1553 | struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); | |
96f6d444 PZ |
1554 | int *recursion = perf_swcounter_recursion_context(cpuctx); |
1555 | ||
1556 | if (*recursion) | |
1557 | goto out; | |
1558 | ||
1559 | (*recursion)++; | |
1560 | barrier(); | |
15dbf27c | 1561 | |
b8e83514 PZ |
1562 | perf_swcounter_ctx_event(&cpuctx->ctx, type, event, nr, nmi, regs); |
1563 | if (cpuctx->task_ctx) { | |
1564 | perf_swcounter_ctx_event(cpuctx->task_ctx, type, event, | |
1565 | nr, nmi, regs); | |
1566 | } | |
15dbf27c | 1567 | |
96f6d444 PZ |
1568 | barrier(); |
1569 | (*recursion)--; | |
1570 | ||
1571 | out: | |
15dbf27c PZ |
1572 | put_cpu_var(perf_cpu_context); |
1573 | } | |
1574 | ||
b8e83514 PZ |
1575 | void perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs) |
1576 | { | |
1577 | __perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, regs); | |
1578 | } | |
1579 | ||
15dbf27c PZ |
1580 | static void perf_swcounter_read(struct perf_counter *counter) |
1581 | { | |
1582 | perf_swcounter_update(counter); | |
1583 | } | |
1584 | ||
1585 | static int perf_swcounter_enable(struct perf_counter *counter) | |
1586 | { | |
1587 | perf_swcounter_set_period(counter); | |
1588 | return 0; | |
1589 | } | |
1590 | ||
1591 | static void perf_swcounter_disable(struct perf_counter *counter) | |
1592 | { | |
1593 | perf_swcounter_update(counter); | |
1594 | } | |
1595 | ||
ac17dc8e PZ |
1596 | static const struct hw_perf_counter_ops perf_ops_generic = { |
1597 | .enable = perf_swcounter_enable, | |
1598 | .disable = perf_swcounter_disable, | |
1599 | .read = perf_swcounter_read, | |
1600 | }; | |
1601 | ||
15dbf27c PZ |
1602 | /* |
1603 | * Software counter: cpu wall time clock | |
1604 | */ | |
1605 | ||
9abf8a08 PM |
1606 | static void cpu_clock_perf_counter_update(struct perf_counter *counter) |
1607 | { | |
1608 | int cpu = raw_smp_processor_id(); | |
1609 | s64 prev; | |
1610 | u64 now; | |
1611 | ||
1612 | now = cpu_clock(cpu); | |
1613 | prev = atomic64_read(&counter->hw.prev_count); | |
1614 | atomic64_set(&counter->hw.prev_count, now); | |
1615 | atomic64_add(now - prev, &counter->count); | |
1616 | } | |
1617 | ||
d6d020e9 PZ |
1618 | static int cpu_clock_perf_counter_enable(struct perf_counter *counter) |
1619 | { | |
1620 | struct hw_perf_counter *hwc = &counter->hw; | |
1621 | int cpu = raw_smp_processor_id(); | |
1622 | ||
1623 | atomic64_set(&hwc->prev_count, cpu_clock(cpu)); | |
039fc91e PZ |
1624 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1625 | hwc->hrtimer.function = perf_swcounter_hrtimer; | |
d6d020e9 | 1626 | if (hwc->irq_period) { |
d6d020e9 PZ |
1627 | __hrtimer_start_range_ns(&hwc->hrtimer, |
1628 | ns_to_ktime(hwc->irq_period), 0, | |
1629 | HRTIMER_MODE_REL, 0); | |
1630 | } | |
1631 | ||
1632 | return 0; | |
1633 | } | |
1634 | ||
5c92d124 IM |
1635 | static void cpu_clock_perf_counter_disable(struct perf_counter *counter) |
1636 | { | |
d6d020e9 | 1637 | hrtimer_cancel(&counter->hw.hrtimer); |
9abf8a08 | 1638 | cpu_clock_perf_counter_update(counter); |
5c92d124 IM |
1639 | } |
1640 | ||
1641 | static void cpu_clock_perf_counter_read(struct perf_counter *counter) | |
1642 | { | |
9abf8a08 | 1643 | cpu_clock_perf_counter_update(counter); |
5c92d124 IM |
1644 | } |
1645 | ||
1646 | static const struct hw_perf_counter_ops perf_ops_cpu_clock = { | |
7671581f IM |
1647 | .enable = cpu_clock_perf_counter_enable, |
1648 | .disable = cpu_clock_perf_counter_disable, | |
1649 | .read = cpu_clock_perf_counter_read, | |
5c92d124 IM |
1650 | }; |
1651 | ||
15dbf27c PZ |
1652 | /* |
1653 | * Software counter: task time clock | |
1654 | */ | |
1655 | ||
aa9c4c0f IM |
1656 | /* |
1657 | * Called from within the scheduler: | |
1658 | */ | |
1659 | static u64 task_clock_perf_counter_val(struct perf_counter *counter, int update) | |
bae43c99 | 1660 | { |
aa9c4c0f IM |
1661 | struct task_struct *curr = counter->task; |
1662 | u64 delta; | |
1663 | ||
aa9c4c0f IM |
1664 | delta = __task_delta_exec(curr, update); |
1665 | ||
1666 | return curr->se.sum_exec_runtime + delta; | |
1667 | } | |
1668 | ||
1669 | static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now) | |
1670 | { | |
1671 | u64 prev; | |
8cb391e8 IM |
1672 | s64 delta; |
1673 | ||
1674 | prev = atomic64_read(&counter->hw.prev_count); | |
8cb391e8 IM |
1675 | |
1676 | atomic64_set(&counter->hw.prev_count, now); | |
1677 | ||
1678 | delta = now - prev; | |
8cb391e8 IM |
1679 | |
1680 | atomic64_add(delta, &counter->count); | |
bae43c99 IM |
1681 | } |
1682 | ||
95cdd2e7 | 1683 | static int task_clock_perf_counter_enable(struct perf_counter *counter) |
8cb391e8 | 1684 | { |
d6d020e9 PZ |
1685 | struct hw_perf_counter *hwc = &counter->hw; |
1686 | ||
1687 | atomic64_set(&hwc->prev_count, task_clock_perf_counter_val(counter, 0)); | |
039fc91e PZ |
1688 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1689 | hwc->hrtimer.function = perf_swcounter_hrtimer; | |
d6d020e9 | 1690 | if (hwc->irq_period) { |
d6d020e9 PZ |
1691 | __hrtimer_start_range_ns(&hwc->hrtimer, |
1692 | ns_to_ktime(hwc->irq_period), 0, | |
1693 | HRTIMER_MODE_REL, 0); | |
1694 | } | |
95cdd2e7 IM |
1695 | |
1696 | return 0; | |
8cb391e8 IM |
1697 | } |
1698 | ||
1699 | static void task_clock_perf_counter_disable(struct perf_counter *counter) | |
bae43c99 | 1700 | { |
d6d020e9 PZ |
1701 | hrtimer_cancel(&counter->hw.hrtimer); |
1702 | task_clock_perf_counter_update(counter, | |
1703 | task_clock_perf_counter_val(counter, 0)); | |
1704 | } | |
aa9c4c0f | 1705 | |
d6d020e9 PZ |
1706 | static void task_clock_perf_counter_read(struct perf_counter *counter) |
1707 | { | |
1708 | task_clock_perf_counter_update(counter, | |
1709 | task_clock_perf_counter_val(counter, 1)); | |
bae43c99 IM |
1710 | } |
1711 | ||
1712 | static const struct hw_perf_counter_ops perf_ops_task_clock = { | |
7671581f IM |
1713 | .enable = task_clock_perf_counter_enable, |
1714 | .disable = task_clock_perf_counter_disable, | |
1715 | .read = task_clock_perf_counter_read, | |
bae43c99 IM |
1716 | }; |
1717 | ||
15dbf27c PZ |
1718 | /* |
1719 | * Software counter: cpu migrations | |
1720 | */ | |
1721 | ||
23a185ca | 1722 | static inline u64 get_cpu_migrations(struct perf_counter *counter) |
6c594c21 | 1723 | { |
23a185ca PM |
1724 | struct task_struct *curr = counter->ctx->task; |
1725 | ||
1726 | if (curr) | |
1727 | return curr->se.nr_migrations; | |
1728 | return cpu_nr_migrations(smp_processor_id()); | |
6c594c21 IM |
1729 | } |
1730 | ||
1731 | static void cpu_migrations_perf_counter_update(struct perf_counter *counter) | |
1732 | { | |
1733 | u64 prev, now; | |
1734 | s64 delta; | |
1735 | ||
1736 | prev = atomic64_read(&counter->hw.prev_count); | |
23a185ca | 1737 | now = get_cpu_migrations(counter); |
6c594c21 IM |
1738 | |
1739 | atomic64_set(&counter->hw.prev_count, now); | |
1740 | ||
1741 | delta = now - prev; | |
6c594c21 IM |
1742 | |
1743 | atomic64_add(delta, &counter->count); | |
1744 | } | |
1745 | ||
1746 | static void cpu_migrations_perf_counter_read(struct perf_counter *counter) | |
1747 | { | |
1748 | cpu_migrations_perf_counter_update(counter); | |
1749 | } | |
1750 | ||
95cdd2e7 | 1751 | static int cpu_migrations_perf_counter_enable(struct perf_counter *counter) |
6c594c21 | 1752 | { |
c07c99b6 PM |
1753 | if (counter->prev_state <= PERF_COUNTER_STATE_OFF) |
1754 | atomic64_set(&counter->hw.prev_count, | |
1755 | get_cpu_migrations(counter)); | |
95cdd2e7 | 1756 | return 0; |
6c594c21 IM |
1757 | } |
1758 | ||
1759 | static void cpu_migrations_perf_counter_disable(struct perf_counter *counter) | |
1760 | { | |
1761 | cpu_migrations_perf_counter_update(counter); | |
1762 | } | |
1763 | ||
1764 | static const struct hw_perf_counter_ops perf_ops_cpu_migrations = { | |
7671581f IM |
1765 | .enable = cpu_migrations_perf_counter_enable, |
1766 | .disable = cpu_migrations_perf_counter_disable, | |
1767 | .read = cpu_migrations_perf_counter_read, | |
6c594c21 IM |
1768 | }; |
1769 | ||
e077df4f PZ |
1770 | #ifdef CONFIG_EVENT_PROFILE |
1771 | void perf_tpcounter_event(int event_id) | |
1772 | { | |
b8e83514 PZ |
1773 | struct pt_regs *regs = get_irq_regs(); |
1774 | ||
1775 | if (!regs) | |
1776 | regs = task_pt_regs(current); | |
1777 | ||
1778 | __perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, regs); | |
e077df4f PZ |
1779 | } |
1780 | ||
1781 | extern int ftrace_profile_enable(int); | |
1782 | extern void ftrace_profile_disable(int); | |
1783 | ||
1784 | static void tp_perf_counter_destroy(struct perf_counter *counter) | |
1785 | { | |
f4a2deb4 | 1786 | ftrace_profile_disable(perf_event_id(&counter->hw_event)); |
e077df4f PZ |
1787 | } |
1788 | ||
1789 | static const struct hw_perf_counter_ops * | |
1790 | tp_perf_counter_init(struct perf_counter *counter) | |
1791 | { | |
f4a2deb4 | 1792 | int event_id = perf_event_id(&counter->hw_event); |
e077df4f PZ |
1793 | int ret; |
1794 | ||
1795 | ret = ftrace_profile_enable(event_id); | |
1796 | if (ret) | |
1797 | return NULL; | |
1798 | ||
1799 | counter->destroy = tp_perf_counter_destroy; | |
b8e83514 | 1800 | counter->hw.irq_period = counter->hw_event.irq_period; |
e077df4f PZ |
1801 | |
1802 | return &perf_ops_generic; | |
1803 | } | |
1804 | #else | |
1805 | static const struct hw_perf_counter_ops * | |
1806 | tp_perf_counter_init(struct perf_counter *counter) | |
1807 | { | |
1808 | return NULL; | |
1809 | } | |
1810 | #endif | |
1811 | ||
5c92d124 IM |
1812 | static const struct hw_perf_counter_ops * |
1813 | sw_perf_counter_init(struct perf_counter *counter) | |
1814 | { | |
15dbf27c | 1815 | struct perf_counter_hw_event *hw_event = &counter->hw_event; |
5c92d124 | 1816 | const struct hw_perf_counter_ops *hw_ops = NULL; |
15dbf27c | 1817 | struct hw_perf_counter *hwc = &counter->hw; |
5c92d124 | 1818 | |
0475f9ea PM |
1819 | /* |
1820 | * Software counters (currently) can't in general distinguish | |
1821 | * between user, kernel and hypervisor events. | |
1822 | * However, context switches and cpu migrations are considered | |
1823 | * to be kernel events, and page faults are never hypervisor | |
1824 | * events. | |
1825 | */ | |
f4a2deb4 | 1826 | switch (perf_event_id(&counter->hw_event)) { |
5c92d124 | 1827 | case PERF_COUNT_CPU_CLOCK: |
d6d020e9 PZ |
1828 | hw_ops = &perf_ops_cpu_clock; |
1829 | ||
1830 | if (hw_event->irq_period && hw_event->irq_period < 10000) | |
1831 | hw_event->irq_period = 10000; | |
5c92d124 | 1832 | break; |
bae43c99 | 1833 | case PERF_COUNT_TASK_CLOCK: |
23a185ca PM |
1834 | /* |
1835 | * If the user instantiates this as a per-cpu counter, | |
1836 | * use the cpu_clock counter instead. | |
1837 | */ | |
1838 | if (counter->ctx->task) | |
1839 | hw_ops = &perf_ops_task_clock; | |
1840 | else | |
1841 | hw_ops = &perf_ops_cpu_clock; | |
d6d020e9 PZ |
1842 | |
1843 | if (hw_event->irq_period && hw_event->irq_period < 10000) | |
1844 | hw_event->irq_period = 10000; | |
bae43c99 | 1845 | break; |
e06c61a8 | 1846 | case PERF_COUNT_PAGE_FAULTS: |
ac17dc8e PZ |
1847 | case PERF_COUNT_PAGE_FAULTS_MIN: |
1848 | case PERF_COUNT_PAGE_FAULTS_MAJ: | |
5d6a27d8 | 1849 | case PERF_COUNT_CONTEXT_SWITCHES: |
4a0deca6 | 1850 | hw_ops = &perf_ops_generic; |
5d6a27d8 | 1851 | break; |
6c594c21 | 1852 | case PERF_COUNT_CPU_MIGRATIONS: |
0475f9ea PM |
1853 | if (!counter->hw_event.exclude_kernel) |
1854 | hw_ops = &perf_ops_cpu_migrations; | |
6c594c21 | 1855 | break; |
5c92d124 | 1856 | } |
15dbf27c PZ |
1857 | |
1858 | if (hw_ops) | |
1859 | hwc->irq_period = hw_event->irq_period; | |
1860 | ||
5c92d124 IM |
1861 | return hw_ops; |
1862 | } | |
1863 | ||
0793a61d TG |
1864 | /* |
1865 | * Allocate and initialize a counter structure | |
1866 | */ | |
1867 | static struct perf_counter * | |
04289bb9 IM |
1868 | perf_counter_alloc(struct perf_counter_hw_event *hw_event, |
1869 | int cpu, | |
23a185ca | 1870 | struct perf_counter_context *ctx, |
9b51f66d IM |
1871 | struct perf_counter *group_leader, |
1872 | gfp_t gfpflags) | |
0793a61d | 1873 | { |
5c92d124 | 1874 | const struct hw_perf_counter_ops *hw_ops; |
621a01ea | 1875 | struct perf_counter *counter; |
0793a61d | 1876 | |
9b51f66d | 1877 | counter = kzalloc(sizeof(*counter), gfpflags); |
0793a61d TG |
1878 | if (!counter) |
1879 | return NULL; | |
1880 | ||
04289bb9 IM |
1881 | /* |
1882 | * Single counters are their own group leaders, with an | |
1883 | * empty sibling list: | |
1884 | */ | |
1885 | if (!group_leader) | |
1886 | group_leader = counter; | |
1887 | ||
0793a61d | 1888 | mutex_init(&counter->mutex); |
04289bb9 | 1889 | INIT_LIST_HEAD(&counter->list_entry); |
592903cd | 1890 | INIT_LIST_HEAD(&counter->event_entry); |
04289bb9 | 1891 | INIT_LIST_HEAD(&counter->sibling_list); |
0793a61d TG |
1892 | init_waitqueue_head(&counter->waitq); |
1893 | ||
d859e29f PM |
1894 | INIT_LIST_HEAD(&counter->child_list); |
1895 | ||
9f66a381 IM |
1896 | counter->irqdata = &counter->data[0]; |
1897 | counter->usrdata = &counter->data[1]; | |
1898 | counter->cpu = cpu; | |
1899 | counter->hw_event = *hw_event; | |
1900 | counter->wakeup_pending = 0; | |
04289bb9 | 1901 | counter->group_leader = group_leader; |
621a01ea | 1902 | counter->hw_ops = NULL; |
23a185ca | 1903 | counter->ctx = ctx; |
621a01ea | 1904 | |
235c7fc7 | 1905 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
a86ed508 IM |
1906 | if (hw_event->disabled) |
1907 | counter->state = PERF_COUNTER_STATE_OFF; | |
1908 | ||
5c92d124 | 1909 | hw_ops = NULL; |
b8e83514 | 1910 | |
f4a2deb4 | 1911 | if (perf_event_raw(hw_event)) { |
b8e83514 | 1912 | hw_ops = hw_perf_counter_init(counter); |
f4a2deb4 PZ |
1913 | goto done; |
1914 | } | |
1915 | ||
1916 | switch (perf_event_type(hw_event)) { | |
b8e83514 | 1917 | case PERF_TYPE_HARDWARE: |
5c92d124 | 1918 | hw_ops = hw_perf_counter_init(counter); |
b8e83514 PZ |
1919 | break; |
1920 | ||
1921 | case PERF_TYPE_SOFTWARE: | |
1922 | hw_ops = sw_perf_counter_init(counter); | |
1923 | break; | |
1924 | ||
1925 | case PERF_TYPE_TRACEPOINT: | |
1926 | hw_ops = tp_perf_counter_init(counter); | |
1927 | break; | |
1928 | } | |
5c92d124 | 1929 | |
621a01ea IM |
1930 | if (!hw_ops) { |
1931 | kfree(counter); | |
1932 | return NULL; | |
1933 | } | |
f4a2deb4 | 1934 | done: |
621a01ea | 1935 | counter->hw_ops = hw_ops; |
0793a61d TG |
1936 | |
1937 | return counter; | |
1938 | } | |
1939 | ||
1940 | /** | |
2743a5b0 | 1941 | * sys_perf_counter_open - open a performance counter, associate it to a task/cpu |
9f66a381 IM |
1942 | * |
1943 | * @hw_event_uptr: event type attributes for monitoring/sampling | |
0793a61d | 1944 | * @pid: target pid |
9f66a381 IM |
1945 | * @cpu: target cpu |
1946 | * @group_fd: group leader counter fd | |
0793a61d | 1947 | */ |
2743a5b0 | 1948 | SYSCALL_DEFINE5(perf_counter_open, |
f3dfd265 | 1949 | const struct perf_counter_hw_event __user *, hw_event_uptr, |
2743a5b0 | 1950 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
0793a61d | 1951 | { |
04289bb9 | 1952 | struct perf_counter *counter, *group_leader; |
9f66a381 | 1953 | struct perf_counter_hw_event hw_event; |
04289bb9 | 1954 | struct perf_counter_context *ctx; |
9b51f66d | 1955 | struct file *counter_file = NULL; |
04289bb9 IM |
1956 | struct file *group_file = NULL; |
1957 | int fput_needed = 0; | |
9b51f66d | 1958 | int fput_needed2 = 0; |
0793a61d TG |
1959 | int ret; |
1960 | ||
2743a5b0 PM |
1961 | /* for future expandability... */ |
1962 | if (flags) | |
1963 | return -EINVAL; | |
1964 | ||
9f66a381 | 1965 | if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0) |
eab656ae TG |
1966 | return -EFAULT; |
1967 | ||
04289bb9 | 1968 | /* |
ccff286d IM |
1969 | * Get the target context (task or percpu): |
1970 | */ | |
1971 | ctx = find_get_context(pid, cpu); | |
1972 | if (IS_ERR(ctx)) | |
1973 | return PTR_ERR(ctx); | |
1974 | ||
1975 | /* | |
1976 | * Look up the group leader (we will attach this counter to it): | |
04289bb9 IM |
1977 | */ |
1978 | group_leader = NULL; | |
1979 | if (group_fd != -1) { | |
1980 | ret = -EINVAL; | |
1981 | group_file = fget_light(group_fd, &fput_needed); | |
1982 | if (!group_file) | |
ccff286d | 1983 | goto err_put_context; |
04289bb9 | 1984 | if (group_file->f_op != &perf_fops) |
ccff286d | 1985 | goto err_put_context; |
04289bb9 IM |
1986 | |
1987 | group_leader = group_file->private_data; | |
1988 | /* | |
ccff286d IM |
1989 | * Do not allow a recursive hierarchy (this new sibling |
1990 | * becoming part of another group-sibling): | |
1991 | */ | |
1992 | if (group_leader->group_leader != group_leader) | |
1993 | goto err_put_context; | |
1994 | /* | |
1995 | * Do not allow to attach to a group in a different | |
1996 | * task or CPU context: | |
04289bb9 | 1997 | */ |
ccff286d IM |
1998 | if (group_leader->ctx != ctx) |
1999 | goto err_put_context; | |
3b6f9e5c PM |
2000 | /* |
2001 | * Only a group leader can be exclusive or pinned | |
2002 | */ | |
2003 | if (hw_event.exclusive || hw_event.pinned) | |
2004 | goto err_put_context; | |
04289bb9 IM |
2005 | } |
2006 | ||
5c92d124 | 2007 | ret = -EINVAL; |
23a185ca PM |
2008 | counter = perf_counter_alloc(&hw_event, cpu, ctx, group_leader, |
2009 | GFP_KERNEL); | |
0793a61d TG |
2010 | if (!counter) |
2011 | goto err_put_context; | |
2012 | ||
0793a61d TG |
2013 | ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0); |
2014 | if (ret < 0) | |
9b51f66d IM |
2015 | goto err_free_put_context; |
2016 | ||
2017 | counter_file = fget_light(ret, &fput_needed2); | |
2018 | if (!counter_file) | |
2019 | goto err_free_put_context; | |
2020 | ||
2021 | counter->filp = counter_file; | |
d859e29f | 2022 | mutex_lock(&ctx->mutex); |
9b51f66d | 2023 | perf_install_in_context(ctx, counter, cpu); |
d859e29f | 2024 | mutex_unlock(&ctx->mutex); |
9b51f66d IM |
2025 | |
2026 | fput_light(counter_file, fput_needed2); | |
0793a61d | 2027 | |
04289bb9 IM |
2028 | out_fput: |
2029 | fput_light(group_file, fput_needed); | |
2030 | ||
0793a61d TG |
2031 | return ret; |
2032 | ||
9b51f66d | 2033 | err_free_put_context: |
0793a61d TG |
2034 | kfree(counter); |
2035 | ||
2036 | err_put_context: | |
2037 | put_context(ctx); | |
2038 | ||
04289bb9 | 2039 | goto out_fput; |
0793a61d TG |
2040 | } |
2041 | ||
9b51f66d IM |
2042 | /* |
2043 | * Initialize the perf_counter context in a task_struct: | |
2044 | */ | |
2045 | static void | |
2046 | __perf_counter_init_context(struct perf_counter_context *ctx, | |
2047 | struct task_struct *task) | |
2048 | { | |
2049 | memset(ctx, 0, sizeof(*ctx)); | |
2050 | spin_lock_init(&ctx->lock); | |
d859e29f | 2051 | mutex_init(&ctx->mutex); |
9b51f66d | 2052 | INIT_LIST_HEAD(&ctx->counter_list); |
592903cd | 2053 | INIT_LIST_HEAD(&ctx->event_list); |
9b51f66d IM |
2054 | ctx->task = task; |
2055 | } | |
2056 | ||
2057 | /* | |
2058 | * inherit a counter from parent task to child task: | |
2059 | */ | |
d859e29f | 2060 | static struct perf_counter * |
9b51f66d IM |
2061 | inherit_counter(struct perf_counter *parent_counter, |
2062 | struct task_struct *parent, | |
2063 | struct perf_counter_context *parent_ctx, | |
2064 | struct task_struct *child, | |
d859e29f | 2065 | struct perf_counter *group_leader, |
9b51f66d IM |
2066 | struct perf_counter_context *child_ctx) |
2067 | { | |
2068 | struct perf_counter *child_counter; | |
2069 | ||
d859e29f PM |
2070 | /* |
2071 | * Instead of creating recursive hierarchies of counters, | |
2072 | * we link inherited counters back to the original parent, | |
2073 | * which has a filp for sure, which we use as the reference | |
2074 | * count: | |
2075 | */ | |
2076 | if (parent_counter->parent) | |
2077 | parent_counter = parent_counter->parent; | |
2078 | ||
9b51f66d | 2079 | child_counter = perf_counter_alloc(&parent_counter->hw_event, |
23a185ca PM |
2080 | parent_counter->cpu, child_ctx, |
2081 | group_leader, GFP_KERNEL); | |
9b51f66d | 2082 | if (!child_counter) |
d859e29f | 2083 | return NULL; |
9b51f66d IM |
2084 | |
2085 | /* | |
2086 | * Link it up in the child's context: | |
2087 | */ | |
9b51f66d IM |
2088 | child_counter->task = child; |
2089 | list_add_counter(child_counter, child_ctx); | |
2090 | child_ctx->nr_counters++; | |
2091 | ||
2092 | child_counter->parent = parent_counter; | |
9b51f66d IM |
2093 | /* |
2094 | * inherit into child's child as well: | |
2095 | */ | |
2096 | child_counter->hw_event.inherit = 1; | |
2097 | ||
2098 | /* | |
2099 | * Get a reference to the parent filp - we will fput it | |
2100 | * when the child counter exits. This is safe to do because | |
2101 | * we are in the parent and we know that the filp still | |
2102 | * exists and has a nonzero count: | |
2103 | */ | |
2104 | atomic_long_inc(&parent_counter->filp->f_count); | |
2105 | ||
d859e29f PM |
2106 | /* |
2107 | * Link this into the parent counter's child list | |
2108 | */ | |
2109 | mutex_lock(&parent_counter->mutex); | |
2110 | list_add_tail(&child_counter->child_list, &parent_counter->child_list); | |
2111 | ||
2112 | /* | |
2113 | * Make the child state follow the state of the parent counter, | |
2114 | * not its hw_event.disabled bit. We hold the parent's mutex, | |
2115 | * so we won't race with perf_counter_{en,dis}able_family. | |
2116 | */ | |
2117 | if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE) | |
2118 | child_counter->state = PERF_COUNTER_STATE_INACTIVE; | |
2119 | else | |
2120 | child_counter->state = PERF_COUNTER_STATE_OFF; | |
2121 | ||
2122 | mutex_unlock(&parent_counter->mutex); | |
2123 | ||
2124 | return child_counter; | |
2125 | } | |
2126 | ||
2127 | static int inherit_group(struct perf_counter *parent_counter, | |
2128 | struct task_struct *parent, | |
2129 | struct perf_counter_context *parent_ctx, | |
2130 | struct task_struct *child, | |
2131 | struct perf_counter_context *child_ctx) | |
2132 | { | |
2133 | struct perf_counter *leader; | |
2134 | struct perf_counter *sub; | |
2135 | ||
2136 | leader = inherit_counter(parent_counter, parent, parent_ctx, | |
2137 | child, NULL, child_ctx); | |
2138 | if (!leader) | |
2139 | return -ENOMEM; | |
2140 | list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) { | |
2141 | if (!inherit_counter(sub, parent, parent_ctx, | |
2142 | child, leader, child_ctx)) | |
2143 | return -ENOMEM; | |
2144 | } | |
9b51f66d IM |
2145 | return 0; |
2146 | } | |
2147 | ||
d859e29f PM |
2148 | static void sync_child_counter(struct perf_counter *child_counter, |
2149 | struct perf_counter *parent_counter) | |
2150 | { | |
2151 | u64 parent_val, child_val; | |
2152 | ||
2153 | parent_val = atomic64_read(&parent_counter->count); | |
2154 | child_val = atomic64_read(&child_counter->count); | |
2155 | ||
2156 | /* | |
2157 | * Add back the child's count to the parent's count: | |
2158 | */ | |
2159 | atomic64_add(child_val, &parent_counter->count); | |
2160 | ||
2161 | /* | |
2162 | * Remove this counter from the parent's list | |
2163 | */ | |
2164 | mutex_lock(&parent_counter->mutex); | |
2165 | list_del_init(&child_counter->child_list); | |
2166 | mutex_unlock(&parent_counter->mutex); | |
2167 | ||
2168 | /* | |
2169 | * Release the parent counter, if this was the last | |
2170 | * reference to it. | |
2171 | */ | |
2172 | fput(parent_counter->filp); | |
2173 | } | |
2174 | ||
9b51f66d IM |
2175 | static void |
2176 | __perf_counter_exit_task(struct task_struct *child, | |
2177 | struct perf_counter *child_counter, | |
2178 | struct perf_counter_context *child_ctx) | |
2179 | { | |
2180 | struct perf_counter *parent_counter; | |
d859e29f | 2181 | struct perf_counter *sub, *tmp; |
9b51f66d IM |
2182 | |
2183 | /* | |
235c7fc7 IM |
2184 | * If we do not self-reap then we have to wait for the |
2185 | * child task to unschedule (it will happen for sure), | |
2186 | * so that its counter is at its final count. (This | |
2187 | * condition triggers rarely - child tasks usually get | |
2188 | * off their CPU before the parent has a chance to | |
2189 | * get this far into the reaping action) | |
9b51f66d | 2190 | */ |
235c7fc7 IM |
2191 | if (child != current) { |
2192 | wait_task_inactive(child, 0); | |
2193 | list_del_init(&child_counter->list_entry); | |
2194 | } else { | |
0cc0c027 | 2195 | struct perf_cpu_context *cpuctx; |
235c7fc7 IM |
2196 | unsigned long flags; |
2197 | u64 perf_flags; | |
2198 | ||
2199 | /* | |
2200 | * Disable and unlink this counter. | |
2201 | * | |
2202 | * Be careful about zapping the list - IRQ/NMI context | |
2203 | * could still be processing it: | |
2204 | */ | |
2205 | curr_rq_lock_irq_save(&flags); | |
2206 | perf_flags = hw_perf_save_disable(); | |
0cc0c027 IM |
2207 | |
2208 | cpuctx = &__get_cpu_var(perf_cpu_context); | |
2209 | ||
d859e29f | 2210 | group_sched_out(child_counter, cpuctx, child_ctx); |
0cc0c027 | 2211 | |
235c7fc7 | 2212 | list_del_init(&child_counter->list_entry); |
0cc0c027 | 2213 | |
235c7fc7 | 2214 | child_ctx->nr_counters--; |
9b51f66d | 2215 | |
235c7fc7 IM |
2216 | hw_perf_restore(perf_flags); |
2217 | curr_rq_unlock_irq_restore(&flags); | |
2218 | } | |
9b51f66d IM |
2219 | |
2220 | parent_counter = child_counter->parent; | |
2221 | /* | |
2222 | * It can happen that parent exits first, and has counters | |
2223 | * that are still around due to the child reference. These | |
2224 | * counters need to be zapped - but otherwise linger. | |
2225 | */ | |
d859e29f PM |
2226 | if (parent_counter) { |
2227 | sync_child_counter(child_counter, parent_counter); | |
2228 | list_for_each_entry_safe(sub, tmp, &child_counter->sibling_list, | |
2229 | list_entry) { | |
4bcf349a | 2230 | if (sub->parent) { |
d859e29f | 2231 | sync_child_counter(sub, sub->parent); |
f1600952 | 2232 | free_counter(sub); |
4bcf349a | 2233 | } |
d859e29f | 2234 | } |
f1600952 | 2235 | free_counter(child_counter); |
4bcf349a | 2236 | } |
9b51f66d IM |
2237 | } |
2238 | ||
2239 | /* | |
d859e29f | 2240 | * When a child task exits, feed back counter values to parent counters. |
9b51f66d | 2241 | * |
d859e29f | 2242 | * Note: we may be running in child context, but the PID is not hashed |
9b51f66d IM |
2243 | * anymore so new counters will not be added. |
2244 | */ | |
2245 | void perf_counter_exit_task(struct task_struct *child) | |
2246 | { | |
2247 | struct perf_counter *child_counter, *tmp; | |
2248 | struct perf_counter_context *child_ctx; | |
2249 | ||
2250 | child_ctx = &child->perf_counter_ctx; | |
2251 | ||
2252 | if (likely(!child_ctx->nr_counters)) | |
2253 | return; | |
2254 | ||
2255 | list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, | |
2256 | list_entry) | |
2257 | __perf_counter_exit_task(child, child_counter, child_ctx); | |
2258 | } | |
2259 | ||
2260 | /* | |
2261 | * Initialize the perf_counter context in task_struct | |
2262 | */ | |
2263 | void perf_counter_init_task(struct task_struct *child) | |
2264 | { | |
2265 | struct perf_counter_context *child_ctx, *parent_ctx; | |
d859e29f | 2266 | struct perf_counter *counter; |
9b51f66d | 2267 | struct task_struct *parent = current; |
9b51f66d IM |
2268 | |
2269 | child_ctx = &child->perf_counter_ctx; | |
2270 | parent_ctx = &parent->perf_counter_ctx; | |
2271 | ||
2272 | __perf_counter_init_context(child_ctx, child); | |
2273 | ||
2274 | /* | |
2275 | * This is executed from the parent task context, so inherit | |
2276 | * counters that have been marked for cloning: | |
2277 | */ | |
2278 | ||
2279 | if (likely(!parent_ctx->nr_counters)) | |
2280 | return; | |
2281 | ||
2282 | /* | |
2283 | * Lock the parent list. No need to lock the child - not PID | |
2284 | * hashed yet and not running, so nobody can access it. | |
2285 | */ | |
d859e29f | 2286 | mutex_lock(&parent_ctx->mutex); |
9b51f66d IM |
2287 | |
2288 | /* | |
2289 | * We dont have to disable NMIs - we are only looking at | |
2290 | * the list, not manipulating it: | |
2291 | */ | |
2292 | list_for_each_entry(counter, &parent_ctx->counter_list, list_entry) { | |
d859e29f | 2293 | if (!counter->hw_event.inherit) |
9b51f66d IM |
2294 | continue; |
2295 | ||
d859e29f | 2296 | if (inherit_group(counter, parent, |
9b51f66d IM |
2297 | parent_ctx, child, child_ctx)) |
2298 | break; | |
2299 | } | |
2300 | ||
d859e29f | 2301 | mutex_unlock(&parent_ctx->mutex); |
9b51f66d IM |
2302 | } |
2303 | ||
04289bb9 | 2304 | static void __cpuinit perf_counter_init_cpu(int cpu) |
0793a61d | 2305 | { |
04289bb9 | 2306 | struct perf_cpu_context *cpuctx; |
0793a61d | 2307 | |
04289bb9 IM |
2308 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
2309 | __perf_counter_init_context(&cpuctx->ctx, NULL); | |
0793a61d TG |
2310 | |
2311 | mutex_lock(&perf_resource_mutex); | |
04289bb9 | 2312 | cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; |
0793a61d | 2313 | mutex_unlock(&perf_resource_mutex); |
04289bb9 | 2314 | |
01d0287f | 2315 | hw_perf_counter_setup(cpu); |
0793a61d TG |
2316 | } |
2317 | ||
2318 | #ifdef CONFIG_HOTPLUG_CPU | |
04289bb9 | 2319 | static void __perf_counter_exit_cpu(void *info) |
0793a61d TG |
2320 | { |
2321 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
2322 | struct perf_counter_context *ctx = &cpuctx->ctx; | |
2323 | struct perf_counter *counter, *tmp; | |
2324 | ||
04289bb9 IM |
2325 | list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) |
2326 | __perf_counter_remove_from_context(counter); | |
0793a61d | 2327 | } |
04289bb9 | 2328 | static void perf_counter_exit_cpu(int cpu) |
0793a61d | 2329 | { |
d859e29f PM |
2330 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
2331 | struct perf_counter_context *ctx = &cpuctx->ctx; | |
2332 | ||
2333 | mutex_lock(&ctx->mutex); | |
04289bb9 | 2334 | smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1); |
d859e29f | 2335 | mutex_unlock(&ctx->mutex); |
0793a61d TG |
2336 | } |
2337 | #else | |
04289bb9 | 2338 | static inline void perf_counter_exit_cpu(int cpu) { } |
0793a61d TG |
2339 | #endif |
2340 | ||
2341 | static int __cpuinit | |
2342 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) | |
2343 | { | |
2344 | unsigned int cpu = (long)hcpu; | |
2345 | ||
2346 | switch (action) { | |
2347 | ||
2348 | case CPU_UP_PREPARE: | |
2349 | case CPU_UP_PREPARE_FROZEN: | |
04289bb9 | 2350 | perf_counter_init_cpu(cpu); |
0793a61d TG |
2351 | break; |
2352 | ||
2353 | case CPU_DOWN_PREPARE: | |
2354 | case CPU_DOWN_PREPARE_FROZEN: | |
04289bb9 | 2355 | perf_counter_exit_cpu(cpu); |
0793a61d TG |
2356 | break; |
2357 | ||
2358 | default: | |
2359 | break; | |
2360 | } | |
2361 | ||
2362 | return NOTIFY_OK; | |
2363 | } | |
2364 | ||
2365 | static struct notifier_block __cpuinitdata perf_cpu_nb = { | |
2366 | .notifier_call = perf_cpu_notify, | |
2367 | }; | |
2368 | ||
2369 | static int __init perf_counter_init(void) | |
2370 | { | |
2371 | perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, | |
2372 | (void *)(long)smp_processor_id()); | |
2373 | register_cpu_notifier(&perf_cpu_nb); | |
2374 | ||
2375 | return 0; | |
2376 | } | |
2377 | early_initcall(perf_counter_init); | |
2378 | ||
2379 | static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) | |
2380 | { | |
2381 | return sprintf(buf, "%d\n", perf_reserved_percpu); | |
2382 | } | |
2383 | ||
2384 | static ssize_t | |
2385 | perf_set_reserve_percpu(struct sysdev_class *class, | |
2386 | const char *buf, | |
2387 | size_t count) | |
2388 | { | |
2389 | struct perf_cpu_context *cpuctx; | |
2390 | unsigned long val; | |
2391 | int err, cpu, mpt; | |
2392 | ||
2393 | err = strict_strtoul(buf, 10, &val); | |
2394 | if (err) | |
2395 | return err; | |
2396 | if (val > perf_max_counters) | |
2397 | return -EINVAL; | |
2398 | ||
2399 | mutex_lock(&perf_resource_mutex); | |
2400 | perf_reserved_percpu = val; | |
2401 | for_each_online_cpu(cpu) { | |
2402 | cpuctx = &per_cpu(perf_cpu_context, cpu); | |
2403 | spin_lock_irq(&cpuctx->ctx.lock); | |
2404 | mpt = min(perf_max_counters - cpuctx->ctx.nr_counters, | |
2405 | perf_max_counters - perf_reserved_percpu); | |
2406 | cpuctx->max_pertask = mpt; | |
2407 | spin_unlock_irq(&cpuctx->ctx.lock); | |
2408 | } | |
2409 | mutex_unlock(&perf_resource_mutex); | |
2410 | ||
2411 | return count; | |
2412 | } | |
2413 | ||
2414 | static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) | |
2415 | { | |
2416 | return sprintf(buf, "%d\n", perf_overcommit); | |
2417 | } | |
2418 | ||
2419 | static ssize_t | |
2420 | perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) | |
2421 | { | |
2422 | unsigned long val; | |
2423 | int err; | |
2424 | ||
2425 | err = strict_strtoul(buf, 10, &val); | |
2426 | if (err) | |
2427 | return err; | |
2428 | if (val > 1) | |
2429 | return -EINVAL; | |
2430 | ||
2431 | mutex_lock(&perf_resource_mutex); | |
2432 | perf_overcommit = val; | |
2433 | mutex_unlock(&perf_resource_mutex); | |
2434 | ||
2435 | return count; | |
2436 | } | |
2437 | ||
2438 | static SYSDEV_CLASS_ATTR( | |
2439 | reserve_percpu, | |
2440 | 0644, | |
2441 | perf_show_reserve_percpu, | |
2442 | perf_set_reserve_percpu | |
2443 | ); | |
2444 | ||
2445 | static SYSDEV_CLASS_ATTR( | |
2446 | overcommit, | |
2447 | 0644, | |
2448 | perf_show_overcommit, | |
2449 | perf_set_overcommit | |
2450 | ); | |
2451 | ||
2452 | static struct attribute *perfclass_attrs[] = { | |
2453 | &attr_reserve_percpu.attr, | |
2454 | &attr_overcommit.attr, | |
2455 | NULL | |
2456 | }; | |
2457 | ||
2458 | static struct attribute_group perfclass_attr_group = { | |
2459 | .attrs = perfclass_attrs, | |
2460 | .name = "perf_counters", | |
2461 | }; | |
2462 | ||
2463 | static int __init perf_counter_sysfs_init(void) | |
2464 | { | |
2465 | return sysfs_create_group(&cpu_sysdev_class.kset.kobj, | |
2466 | &perfclass_attr_group); | |
2467 | } | |
2468 | device_initcall(perf_counter_sysfs_init); |