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> | |
21 | #include <linux/perf_counter.h> | |
22 | ||
23 | /* | |
24 | * Each CPU has a list of per CPU counters: | |
25 | */ | |
26 | DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); | |
27 | ||
28 | int perf_max_counters __read_mostly; | |
29 | static int perf_reserved_percpu __read_mostly; | |
30 | static int perf_overcommit __read_mostly = 1; | |
31 | ||
32 | /* | |
33 | * Mutex for (sysadmin-configurable) counter reservations: | |
34 | */ | |
35 | static DEFINE_MUTEX(perf_resource_mutex); | |
36 | ||
37 | /* | |
38 | * Architecture provided APIs - weak aliases: | |
39 | */ | |
5c92d124 | 40 | extern __weak const struct hw_perf_counter_ops * |
621a01ea | 41 | hw_perf_counter_init(struct perf_counter *counter) |
0793a61d | 42 | { |
621a01ea | 43 | return ERR_PTR(-EINVAL); |
0793a61d TG |
44 | } |
45 | ||
01b2838c | 46 | u64 __weak hw_perf_save_disable(void) { return 0; } |
ee06094f | 47 | void __weak hw_perf_restore(u64 ctrl) { } |
5c92d124 | 48 | void __weak hw_perf_counter_setup(void) { } |
0793a61d | 49 | |
04289bb9 IM |
50 | static void |
51 | list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) | |
52 | { | |
53 | struct perf_counter *group_leader = counter->group_leader; | |
54 | ||
55 | /* | |
56 | * Depending on whether it is a standalone or sibling counter, | |
57 | * add it straight to the context's counter list, or to the group | |
58 | * leader's sibling list: | |
59 | */ | |
60 | if (counter->group_leader == counter) | |
61 | list_add_tail(&counter->list_entry, &ctx->counter_list); | |
62 | else | |
63 | list_add_tail(&counter->list_entry, &group_leader->sibling_list); | |
64 | } | |
65 | ||
66 | static void | |
67 | list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) | |
68 | { | |
69 | struct perf_counter *sibling, *tmp; | |
70 | ||
71 | list_del_init(&counter->list_entry); | |
72 | ||
04289bb9 IM |
73 | /* |
74 | * If this was a group counter with sibling counters then | |
75 | * upgrade the siblings to singleton counters by adding them | |
76 | * to the context list directly: | |
77 | */ | |
78 | list_for_each_entry_safe(sibling, tmp, | |
79 | &counter->sibling_list, list_entry) { | |
80 | ||
81 | list_del_init(&sibling->list_entry); | |
82 | list_add_tail(&sibling->list_entry, &ctx->counter_list); | |
83 | WARN_ON_ONCE(!sibling->group_leader); | |
84 | WARN_ON_ONCE(sibling->group_leader == sibling); | |
85 | sibling->group_leader = sibling; | |
86 | } | |
87 | } | |
88 | ||
0793a61d TG |
89 | /* |
90 | * Cross CPU call to remove a performance counter | |
91 | * | |
92 | * We disable the counter on the hardware level first. After that we | |
93 | * remove it from the context list. | |
94 | */ | |
04289bb9 | 95 | static void __perf_counter_remove_from_context(void *info) |
0793a61d TG |
96 | { |
97 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
98 | struct perf_counter *counter = info; | |
99 | struct perf_counter_context *ctx = counter->ctx; | |
5c92d124 | 100 | u64 perf_flags; |
0793a61d TG |
101 | |
102 | /* | |
103 | * If this is a task context, we need to check whether it is | |
104 | * the current task context of this cpu. If not it has been | |
105 | * scheduled out before the smp call arrived. | |
106 | */ | |
107 | if (ctx->task && cpuctx->task_ctx != ctx) | |
108 | return; | |
109 | ||
110 | spin_lock(&ctx->lock); | |
111 | ||
6a930700 | 112 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { |
621a01ea | 113 | counter->hw_ops->hw_perf_counter_disable(counter); |
6a930700 | 114 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
0793a61d TG |
115 | ctx->nr_active--; |
116 | cpuctx->active_oncpu--; | |
117 | counter->task = NULL; | |
118 | } | |
119 | ctx->nr_counters--; | |
120 | ||
121 | /* | |
122 | * Protect the list operation against NMI by disabling the | |
123 | * counters on a global level. NOP for non NMI based counters. | |
124 | */ | |
01b2838c | 125 | perf_flags = hw_perf_save_disable(); |
04289bb9 | 126 | list_del_counter(counter, ctx); |
01b2838c | 127 | hw_perf_restore(perf_flags); |
0793a61d TG |
128 | |
129 | if (!ctx->task) { | |
130 | /* | |
131 | * Allow more per task counters with respect to the | |
132 | * reservation: | |
133 | */ | |
134 | cpuctx->max_pertask = | |
135 | min(perf_max_counters - ctx->nr_counters, | |
136 | perf_max_counters - perf_reserved_percpu); | |
137 | } | |
138 | ||
139 | spin_unlock(&ctx->lock); | |
140 | } | |
141 | ||
142 | ||
143 | /* | |
144 | * Remove the counter from a task's (or a CPU's) list of counters. | |
145 | * | |
146 | * Must be called with counter->mutex held. | |
147 | * | |
148 | * CPU counters are removed with a smp call. For task counters we only | |
149 | * call when the task is on a CPU. | |
150 | */ | |
04289bb9 | 151 | static void perf_counter_remove_from_context(struct perf_counter *counter) |
0793a61d TG |
152 | { |
153 | struct perf_counter_context *ctx = counter->ctx; | |
154 | struct task_struct *task = ctx->task; | |
155 | ||
156 | if (!task) { | |
157 | /* | |
158 | * Per cpu counters are removed via an smp call and | |
159 | * the removal is always sucessful. | |
160 | */ | |
161 | smp_call_function_single(counter->cpu, | |
04289bb9 | 162 | __perf_counter_remove_from_context, |
0793a61d TG |
163 | counter, 1); |
164 | return; | |
165 | } | |
166 | ||
167 | retry: | |
04289bb9 | 168 | task_oncpu_function_call(task, __perf_counter_remove_from_context, |
0793a61d TG |
169 | counter); |
170 | ||
171 | spin_lock_irq(&ctx->lock); | |
172 | /* | |
173 | * If the context is active we need to retry the smp call. | |
174 | */ | |
04289bb9 | 175 | if (ctx->nr_active && !list_empty(&counter->list_entry)) { |
0793a61d TG |
176 | spin_unlock_irq(&ctx->lock); |
177 | goto retry; | |
178 | } | |
179 | ||
180 | /* | |
181 | * The lock prevents that this context is scheduled in so we | |
04289bb9 | 182 | * can remove the counter safely, if the call above did not |
0793a61d TG |
183 | * succeed. |
184 | */ | |
04289bb9 | 185 | if (!list_empty(&counter->list_entry)) { |
0793a61d | 186 | ctx->nr_counters--; |
04289bb9 | 187 | list_del_counter(counter, ctx); |
0793a61d TG |
188 | counter->task = NULL; |
189 | } | |
190 | spin_unlock_irq(&ctx->lock); | |
191 | } | |
192 | ||
193 | /* | |
194 | * Cross CPU call to install and enable a preformance counter | |
195 | */ | |
196 | static void __perf_install_in_context(void *info) | |
197 | { | |
198 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
199 | struct perf_counter *counter = info; | |
200 | struct perf_counter_context *ctx = counter->ctx; | |
201 | int cpu = smp_processor_id(); | |
5c92d124 | 202 | u64 perf_flags; |
0793a61d TG |
203 | |
204 | /* | |
205 | * If this is a task context, we need to check whether it is | |
206 | * the current task context of this cpu. If not it has been | |
207 | * scheduled out before the smp call arrived. | |
208 | */ | |
209 | if (ctx->task && cpuctx->task_ctx != ctx) | |
210 | return; | |
211 | ||
212 | spin_lock(&ctx->lock); | |
213 | ||
214 | /* | |
215 | * Protect the list operation against NMI by disabling the | |
216 | * counters on a global level. NOP for non NMI based counters. | |
217 | */ | |
01b2838c | 218 | perf_flags = hw_perf_save_disable(); |
04289bb9 | 219 | list_add_counter(counter, ctx); |
01b2838c | 220 | hw_perf_restore(perf_flags); |
0793a61d TG |
221 | |
222 | ctx->nr_counters++; | |
223 | ||
224 | if (cpuctx->active_oncpu < perf_max_counters) { | |
6a930700 | 225 | counter->state = PERF_COUNTER_STATE_ACTIVE; |
0793a61d TG |
226 | counter->oncpu = cpu; |
227 | ctx->nr_active++; | |
228 | cpuctx->active_oncpu++; | |
ee06094f | 229 | counter->hw_ops->hw_perf_counter_enable(counter); |
0793a61d TG |
230 | } |
231 | ||
232 | if (!ctx->task && cpuctx->max_pertask) | |
233 | cpuctx->max_pertask--; | |
234 | ||
235 | spin_unlock(&ctx->lock); | |
236 | } | |
237 | ||
238 | /* | |
239 | * Attach a performance counter to a context | |
240 | * | |
241 | * First we add the counter to the list with the hardware enable bit | |
242 | * in counter->hw_config cleared. | |
243 | * | |
244 | * If the counter is attached to a task which is on a CPU we use a smp | |
245 | * call to enable it in the task context. The task might have been | |
246 | * scheduled away, but we check this in the smp call again. | |
247 | */ | |
248 | static void | |
249 | perf_install_in_context(struct perf_counter_context *ctx, | |
250 | struct perf_counter *counter, | |
251 | int cpu) | |
252 | { | |
253 | struct task_struct *task = ctx->task; | |
254 | ||
255 | counter->ctx = ctx; | |
256 | if (!task) { | |
257 | /* | |
258 | * Per cpu counters are installed via an smp call and | |
259 | * the install is always sucessful. | |
260 | */ | |
261 | smp_call_function_single(cpu, __perf_install_in_context, | |
262 | counter, 1); | |
263 | return; | |
264 | } | |
265 | ||
266 | counter->task = task; | |
267 | retry: | |
268 | task_oncpu_function_call(task, __perf_install_in_context, | |
269 | counter); | |
270 | ||
271 | spin_lock_irq(&ctx->lock); | |
272 | /* | |
0793a61d TG |
273 | * we need to retry the smp call. |
274 | */ | |
04289bb9 | 275 | if (ctx->nr_active && list_empty(&counter->list_entry)) { |
0793a61d TG |
276 | spin_unlock_irq(&ctx->lock); |
277 | goto retry; | |
278 | } | |
279 | ||
280 | /* | |
281 | * The lock prevents that this context is scheduled in so we | |
282 | * can add the counter safely, if it the call above did not | |
283 | * succeed. | |
284 | */ | |
04289bb9 IM |
285 | if (list_empty(&counter->list_entry)) { |
286 | list_add_counter(counter, ctx); | |
0793a61d TG |
287 | ctx->nr_counters++; |
288 | } | |
289 | spin_unlock_irq(&ctx->lock); | |
290 | } | |
291 | ||
04289bb9 IM |
292 | static void |
293 | counter_sched_out(struct perf_counter *counter, | |
294 | struct perf_cpu_context *cpuctx, | |
295 | struct perf_counter_context *ctx) | |
296 | { | |
6a930700 | 297 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) |
04289bb9 IM |
298 | return; |
299 | ||
621a01ea | 300 | counter->hw_ops->hw_perf_counter_disable(counter); |
6a930700 IM |
301 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
302 | counter->oncpu = -1; | |
04289bb9 IM |
303 | |
304 | cpuctx->active_oncpu--; | |
305 | ctx->nr_active--; | |
306 | } | |
307 | ||
308 | static void | |
309 | group_sched_out(struct perf_counter *group_counter, | |
310 | struct perf_cpu_context *cpuctx, | |
311 | struct perf_counter_context *ctx) | |
312 | { | |
313 | struct perf_counter *counter; | |
314 | ||
315 | counter_sched_out(group_counter, cpuctx, ctx); | |
316 | ||
317 | /* | |
318 | * Schedule out siblings (if any): | |
319 | */ | |
320 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) | |
321 | counter_sched_out(counter, cpuctx, ctx); | |
322 | } | |
323 | ||
0793a61d TG |
324 | /* |
325 | * Called from scheduler to remove the counters of the current task, | |
326 | * with interrupts disabled. | |
327 | * | |
328 | * We stop each counter and update the counter value in counter->count. | |
329 | * | |
330 | * This does not protect us against NMI, but hw_perf_counter_disable() | |
331 | * sets the disabled bit in the control field of counter _before_ | |
332 | * accessing the counter control register. If a NMI hits, then it will | |
333 | * not restart the counter. | |
334 | */ | |
335 | void perf_counter_task_sched_out(struct task_struct *task, int cpu) | |
336 | { | |
337 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); | |
338 | struct perf_counter_context *ctx = &task->perf_counter_ctx; | |
339 | struct perf_counter *counter; | |
340 | ||
341 | if (likely(!cpuctx->task_ctx)) | |
342 | return; | |
343 | ||
344 | spin_lock(&ctx->lock); | |
04289bb9 IM |
345 | if (ctx->nr_active) { |
346 | list_for_each_entry(counter, &ctx->counter_list, list_entry) | |
347 | group_sched_out(counter, cpuctx, ctx); | |
0793a61d TG |
348 | } |
349 | spin_unlock(&ctx->lock); | |
350 | cpuctx->task_ctx = NULL; | |
351 | } | |
352 | ||
04289bb9 IM |
353 | static void |
354 | counter_sched_in(struct perf_counter *counter, | |
355 | struct perf_cpu_context *cpuctx, | |
356 | struct perf_counter_context *ctx, | |
357 | int cpu) | |
358 | { | |
6a930700 | 359 | if (counter->state == PERF_COUNTER_STATE_OFF) |
1d1c7ddb IM |
360 | return; |
361 | ||
621a01ea | 362 | counter->hw_ops->hw_perf_counter_enable(counter); |
6a930700 | 363 | counter->state = PERF_COUNTER_STATE_ACTIVE; |
04289bb9 IM |
364 | counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ |
365 | ||
366 | cpuctx->active_oncpu++; | |
367 | ctx->nr_active++; | |
368 | } | |
369 | ||
370 | static void | |
371 | group_sched_in(struct perf_counter *group_counter, | |
372 | struct perf_cpu_context *cpuctx, | |
373 | struct perf_counter_context *ctx, | |
374 | int cpu) | |
375 | { | |
376 | struct perf_counter *counter; | |
377 | ||
378 | counter_sched_in(group_counter, cpuctx, ctx, cpu); | |
379 | ||
380 | /* | |
381 | * Schedule in siblings as one group (if any): | |
382 | */ | |
383 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) | |
384 | counter_sched_in(counter, cpuctx, ctx, cpu); | |
385 | } | |
386 | ||
0793a61d TG |
387 | /* |
388 | * Called from scheduler to add the counters of the current task | |
389 | * with interrupts disabled. | |
390 | * | |
391 | * We restore the counter value and then enable it. | |
392 | * | |
393 | * This does not protect us against NMI, but hw_perf_counter_enable() | |
394 | * sets the enabled bit in the control field of counter _before_ | |
395 | * accessing the counter control register. If a NMI hits, then it will | |
396 | * keep the counter running. | |
397 | */ | |
398 | void perf_counter_task_sched_in(struct task_struct *task, int cpu) | |
399 | { | |
400 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); | |
401 | struct perf_counter_context *ctx = &task->perf_counter_ctx; | |
402 | struct perf_counter *counter; | |
403 | ||
404 | if (likely(!ctx->nr_counters)) | |
405 | return; | |
406 | ||
407 | spin_lock(&ctx->lock); | |
04289bb9 | 408 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
0793a61d TG |
409 | if (ctx->nr_active == cpuctx->max_pertask) |
410 | break; | |
04289bb9 IM |
411 | |
412 | /* | |
413 | * Listen to the 'cpu' scheduling filter constraint | |
414 | * of counters: | |
415 | */ | |
0793a61d TG |
416 | if (counter->cpu != -1 && counter->cpu != cpu) |
417 | continue; | |
418 | ||
04289bb9 | 419 | group_sched_in(counter, cpuctx, ctx, cpu); |
0793a61d TG |
420 | } |
421 | spin_unlock(&ctx->lock); | |
04289bb9 | 422 | |
0793a61d TG |
423 | cpuctx->task_ctx = ctx; |
424 | } | |
425 | ||
1d1c7ddb IM |
426 | int perf_counter_task_disable(void) |
427 | { | |
428 | struct task_struct *curr = current; | |
429 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
430 | struct perf_counter *counter; | |
431 | u64 perf_flags; | |
432 | int cpu; | |
433 | ||
434 | if (likely(!ctx->nr_counters)) | |
435 | return 0; | |
436 | ||
437 | local_irq_disable(); | |
438 | cpu = smp_processor_id(); | |
439 | ||
440 | perf_counter_task_sched_out(curr, cpu); | |
441 | ||
442 | spin_lock(&ctx->lock); | |
443 | ||
444 | /* | |
445 | * Disable all the counters: | |
446 | */ | |
447 | perf_flags = hw_perf_save_disable(); | |
448 | ||
449 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { | |
6a930700 IM |
450 | WARN_ON_ONCE(counter->state == PERF_COUNTER_STATE_ACTIVE); |
451 | counter->state = PERF_COUNTER_STATE_OFF; | |
1d1c7ddb IM |
452 | } |
453 | hw_perf_restore(perf_flags); | |
454 | ||
455 | spin_unlock(&ctx->lock); | |
456 | ||
457 | local_irq_enable(); | |
458 | ||
459 | return 0; | |
460 | } | |
461 | ||
462 | int perf_counter_task_enable(void) | |
463 | { | |
464 | struct task_struct *curr = current; | |
465 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
466 | struct perf_counter *counter; | |
467 | u64 perf_flags; | |
468 | int cpu; | |
469 | ||
470 | if (likely(!ctx->nr_counters)) | |
471 | return 0; | |
472 | ||
473 | local_irq_disable(); | |
474 | cpu = smp_processor_id(); | |
475 | ||
476 | spin_lock(&ctx->lock); | |
477 | ||
478 | /* | |
479 | * Disable all the counters: | |
480 | */ | |
481 | perf_flags = hw_perf_save_disable(); | |
482 | ||
483 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { | |
6a930700 | 484 | if (counter->state != PERF_COUNTER_STATE_OFF) |
1d1c7ddb | 485 | continue; |
6a930700 | 486 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
1d1c7ddb IM |
487 | } |
488 | hw_perf_restore(perf_flags); | |
489 | ||
490 | spin_unlock(&ctx->lock); | |
491 | ||
492 | perf_counter_task_sched_in(curr, cpu); | |
493 | ||
494 | local_irq_enable(); | |
495 | ||
496 | return 0; | |
497 | } | |
498 | ||
0793a61d TG |
499 | void perf_counter_task_tick(struct task_struct *curr, int cpu) |
500 | { | |
501 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; | |
502 | struct perf_counter *counter; | |
5c92d124 | 503 | u64 perf_flags; |
0793a61d TG |
504 | |
505 | if (likely(!ctx->nr_counters)) | |
506 | return; | |
507 | ||
508 | perf_counter_task_sched_out(curr, cpu); | |
509 | ||
510 | spin_lock(&ctx->lock); | |
511 | ||
512 | /* | |
04289bb9 | 513 | * Rotate the first entry last (works just fine for group counters too): |
0793a61d | 514 | */ |
01b2838c | 515 | perf_flags = hw_perf_save_disable(); |
04289bb9 IM |
516 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
517 | list_del(&counter->list_entry); | |
518 | list_add_tail(&counter->list_entry, &ctx->counter_list); | |
0793a61d TG |
519 | break; |
520 | } | |
01b2838c | 521 | hw_perf_restore(perf_flags); |
0793a61d TG |
522 | |
523 | spin_unlock(&ctx->lock); | |
524 | ||
525 | perf_counter_task_sched_in(curr, cpu); | |
526 | } | |
527 | ||
04289bb9 IM |
528 | /* |
529 | * Initialize the perf_counter context in a task_struct: | |
530 | */ | |
531 | static void | |
532 | __perf_counter_init_context(struct perf_counter_context *ctx, | |
533 | struct task_struct *task) | |
534 | { | |
535 | spin_lock_init(&ctx->lock); | |
536 | INIT_LIST_HEAD(&ctx->counter_list); | |
537 | ctx->nr_counters = 0; | |
538 | ctx->task = task; | |
539 | } | |
0793a61d TG |
540 | /* |
541 | * Initialize the perf_counter context in task_struct | |
542 | */ | |
543 | void perf_counter_init_task(struct task_struct *task) | |
544 | { | |
04289bb9 | 545 | __perf_counter_init_context(&task->perf_counter_ctx, task); |
0793a61d TG |
546 | } |
547 | ||
548 | /* | |
549 | * Cross CPU call to read the hardware counter | |
550 | */ | |
551 | static void __hw_perf_counter_read(void *info) | |
552 | { | |
621a01ea IM |
553 | struct perf_counter *counter = info; |
554 | ||
555 | counter->hw_ops->hw_perf_counter_read(counter); | |
0793a61d TG |
556 | } |
557 | ||
04289bb9 | 558 | static u64 perf_counter_read(struct perf_counter *counter) |
0793a61d TG |
559 | { |
560 | /* | |
561 | * If counter is enabled and currently active on a CPU, update the | |
562 | * value in the counter structure: | |
563 | */ | |
6a930700 | 564 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { |
0793a61d TG |
565 | smp_call_function_single(counter->oncpu, |
566 | __hw_perf_counter_read, counter, 1); | |
567 | } | |
568 | ||
ee06094f | 569 | return atomic64_read(&counter->count); |
0793a61d TG |
570 | } |
571 | ||
572 | /* | |
573 | * Cross CPU call to switch performance data pointers | |
574 | */ | |
575 | static void __perf_switch_irq_data(void *info) | |
576 | { | |
577 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
578 | struct perf_counter *counter = info; | |
579 | struct perf_counter_context *ctx = counter->ctx; | |
580 | struct perf_data *oldirqdata = counter->irqdata; | |
581 | ||
582 | /* | |
583 | * If this is a task context, we need to check whether it is | |
584 | * the current task context of this cpu. If not it has been | |
585 | * scheduled out before the smp call arrived. | |
586 | */ | |
587 | if (ctx->task) { | |
588 | if (cpuctx->task_ctx != ctx) | |
589 | return; | |
590 | spin_lock(&ctx->lock); | |
591 | } | |
592 | ||
593 | /* Change the pointer NMI safe */ | |
594 | atomic_long_set((atomic_long_t *)&counter->irqdata, | |
595 | (unsigned long) counter->usrdata); | |
596 | counter->usrdata = oldirqdata; | |
597 | ||
598 | if (ctx->task) | |
599 | spin_unlock(&ctx->lock); | |
600 | } | |
601 | ||
602 | static struct perf_data *perf_switch_irq_data(struct perf_counter *counter) | |
603 | { | |
604 | struct perf_counter_context *ctx = counter->ctx; | |
605 | struct perf_data *oldirqdata = counter->irqdata; | |
606 | struct task_struct *task = ctx->task; | |
607 | ||
608 | if (!task) { | |
609 | smp_call_function_single(counter->cpu, | |
610 | __perf_switch_irq_data, | |
611 | counter, 1); | |
612 | return counter->usrdata; | |
613 | } | |
614 | ||
615 | retry: | |
616 | spin_lock_irq(&ctx->lock); | |
6a930700 | 617 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) { |
0793a61d TG |
618 | counter->irqdata = counter->usrdata; |
619 | counter->usrdata = oldirqdata; | |
620 | spin_unlock_irq(&ctx->lock); | |
621 | return oldirqdata; | |
622 | } | |
623 | spin_unlock_irq(&ctx->lock); | |
624 | task_oncpu_function_call(task, __perf_switch_irq_data, counter); | |
625 | /* Might have failed, because task was scheduled out */ | |
626 | if (counter->irqdata == oldirqdata) | |
627 | goto retry; | |
628 | ||
629 | return counter->usrdata; | |
630 | } | |
631 | ||
632 | static void put_context(struct perf_counter_context *ctx) | |
633 | { | |
634 | if (ctx->task) | |
635 | put_task_struct(ctx->task); | |
636 | } | |
637 | ||
638 | static struct perf_counter_context *find_get_context(pid_t pid, int cpu) | |
639 | { | |
640 | struct perf_cpu_context *cpuctx; | |
641 | struct perf_counter_context *ctx; | |
642 | struct task_struct *task; | |
643 | ||
644 | /* | |
645 | * If cpu is not a wildcard then this is a percpu counter: | |
646 | */ | |
647 | if (cpu != -1) { | |
648 | /* Must be root to operate on a CPU counter: */ | |
649 | if (!capable(CAP_SYS_ADMIN)) | |
650 | return ERR_PTR(-EACCES); | |
651 | ||
652 | if (cpu < 0 || cpu > num_possible_cpus()) | |
653 | return ERR_PTR(-EINVAL); | |
654 | ||
655 | /* | |
656 | * We could be clever and allow to attach a counter to an | |
657 | * offline CPU and activate it when the CPU comes up, but | |
658 | * that's for later. | |
659 | */ | |
660 | if (!cpu_isset(cpu, cpu_online_map)) | |
661 | return ERR_PTR(-ENODEV); | |
662 | ||
663 | cpuctx = &per_cpu(perf_cpu_context, cpu); | |
664 | ctx = &cpuctx->ctx; | |
665 | ||
666 | WARN_ON_ONCE(ctx->task); | |
667 | return ctx; | |
668 | } | |
669 | ||
670 | rcu_read_lock(); | |
671 | if (!pid) | |
672 | task = current; | |
673 | else | |
674 | task = find_task_by_vpid(pid); | |
675 | if (task) | |
676 | get_task_struct(task); | |
677 | rcu_read_unlock(); | |
678 | ||
679 | if (!task) | |
680 | return ERR_PTR(-ESRCH); | |
681 | ||
682 | ctx = &task->perf_counter_ctx; | |
683 | ctx->task = task; | |
684 | ||
685 | /* Reuse ptrace permission checks for now. */ | |
686 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) { | |
687 | put_context(ctx); | |
688 | return ERR_PTR(-EACCES); | |
689 | } | |
690 | ||
691 | return ctx; | |
692 | } | |
693 | ||
694 | /* | |
695 | * Called when the last reference to the file is gone. | |
696 | */ | |
697 | static int perf_release(struct inode *inode, struct file *file) | |
698 | { | |
699 | struct perf_counter *counter = file->private_data; | |
700 | struct perf_counter_context *ctx = counter->ctx; | |
701 | ||
702 | file->private_data = NULL; | |
703 | ||
704 | mutex_lock(&counter->mutex); | |
705 | ||
04289bb9 | 706 | perf_counter_remove_from_context(counter); |
0793a61d TG |
707 | put_context(ctx); |
708 | ||
709 | mutex_unlock(&counter->mutex); | |
710 | ||
711 | kfree(counter); | |
712 | ||
713 | return 0; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Read the performance counter - simple non blocking version for now | |
718 | */ | |
719 | static ssize_t | |
720 | perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) | |
721 | { | |
722 | u64 cntval; | |
723 | ||
724 | if (count != sizeof(cntval)) | |
725 | return -EINVAL; | |
726 | ||
727 | mutex_lock(&counter->mutex); | |
04289bb9 | 728 | cntval = perf_counter_read(counter); |
0793a61d TG |
729 | mutex_unlock(&counter->mutex); |
730 | ||
731 | return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval); | |
732 | } | |
733 | ||
734 | static ssize_t | |
735 | perf_copy_usrdata(struct perf_data *usrdata, char __user *buf, size_t count) | |
736 | { | |
737 | if (!usrdata->len) | |
738 | return 0; | |
739 | ||
740 | count = min(count, (size_t)usrdata->len); | |
741 | if (copy_to_user(buf, usrdata->data + usrdata->rd_idx, count)) | |
742 | return -EFAULT; | |
743 | ||
744 | /* Adjust the counters */ | |
745 | usrdata->len -= count; | |
746 | if (!usrdata->len) | |
747 | usrdata->rd_idx = 0; | |
748 | else | |
749 | usrdata->rd_idx += count; | |
750 | ||
751 | return count; | |
752 | } | |
753 | ||
754 | static ssize_t | |
755 | perf_read_irq_data(struct perf_counter *counter, | |
756 | char __user *buf, | |
757 | size_t count, | |
758 | int nonblocking) | |
759 | { | |
760 | struct perf_data *irqdata, *usrdata; | |
761 | DECLARE_WAITQUEUE(wait, current); | |
762 | ssize_t res; | |
763 | ||
764 | irqdata = counter->irqdata; | |
765 | usrdata = counter->usrdata; | |
766 | ||
767 | if (usrdata->len + irqdata->len >= count) | |
768 | goto read_pending; | |
769 | ||
770 | if (nonblocking) | |
771 | return -EAGAIN; | |
772 | ||
773 | spin_lock_irq(&counter->waitq.lock); | |
774 | __add_wait_queue(&counter->waitq, &wait); | |
775 | for (;;) { | |
776 | set_current_state(TASK_INTERRUPTIBLE); | |
777 | if (usrdata->len + irqdata->len >= count) | |
778 | break; | |
779 | ||
780 | if (signal_pending(current)) | |
781 | break; | |
782 | ||
783 | spin_unlock_irq(&counter->waitq.lock); | |
784 | schedule(); | |
785 | spin_lock_irq(&counter->waitq.lock); | |
786 | } | |
787 | __remove_wait_queue(&counter->waitq, &wait); | |
788 | __set_current_state(TASK_RUNNING); | |
789 | spin_unlock_irq(&counter->waitq.lock); | |
790 | ||
791 | if (usrdata->len + irqdata->len < count) | |
792 | return -ERESTARTSYS; | |
793 | read_pending: | |
794 | mutex_lock(&counter->mutex); | |
795 | ||
796 | /* Drain pending data first: */ | |
797 | res = perf_copy_usrdata(usrdata, buf, count); | |
798 | if (res < 0 || res == count) | |
799 | goto out; | |
800 | ||
801 | /* Switch irq buffer: */ | |
802 | usrdata = perf_switch_irq_data(counter); | |
803 | if (perf_copy_usrdata(usrdata, buf + res, count - res) < 0) { | |
804 | if (!res) | |
805 | res = -EFAULT; | |
806 | } else { | |
807 | res = count; | |
808 | } | |
809 | out: | |
810 | mutex_unlock(&counter->mutex); | |
811 | ||
812 | return res; | |
813 | } | |
814 | ||
815 | static ssize_t | |
816 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
817 | { | |
818 | struct perf_counter *counter = file->private_data; | |
819 | ||
9f66a381 | 820 | switch (counter->hw_event.record_type) { |
0793a61d TG |
821 | case PERF_RECORD_SIMPLE: |
822 | return perf_read_hw(counter, buf, count); | |
823 | ||
824 | case PERF_RECORD_IRQ: | |
825 | case PERF_RECORD_GROUP: | |
826 | return perf_read_irq_data(counter, buf, count, | |
827 | file->f_flags & O_NONBLOCK); | |
828 | } | |
829 | return -EINVAL; | |
830 | } | |
831 | ||
832 | static unsigned int perf_poll(struct file *file, poll_table *wait) | |
833 | { | |
834 | struct perf_counter *counter = file->private_data; | |
835 | unsigned int events = 0; | |
836 | unsigned long flags; | |
837 | ||
838 | poll_wait(file, &counter->waitq, wait); | |
839 | ||
840 | spin_lock_irqsave(&counter->waitq.lock, flags); | |
841 | if (counter->usrdata->len || counter->irqdata->len) | |
842 | events |= POLLIN; | |
843 | spin_unlock_irqrestore(&counter->waitq.lock, flags); | |
844 | ||
845 | return events; | |
846 | } | |
847 | ||
848 | static const struct file_operations perf_fops = { | |
849 | .release = perf_release, | |
850 | .read = perf_read, | |
851 | .poll = perf_poll, | |
852 | }; | |
853 | ||
5c92d124 IM |
854 | static void cpu_clock_perf_counter_enable(struct perf_counter *counter) |
855 | { | |
856 | } | |
857 | ||
858 | static void cpu_clock_perf_counter_disable(struct perf_counter *counter) | |
859 | { | |
860 | } | |
861 | ||
862 | static void cpu_clock_perf_counter_read(struct perf_counter *counter) | |
863 | { | |
864 | int cpu = raw_smp_processor_id(); | |
865 | ||
ee06094f | 866 | atomic64_set(&counter->count, cpu_clock(cpu)); |
5c92d124 IM |
867 | } |
868 | ||
869 | static const struct hw_perf_counter_ops perf_ops_cpu_clock = { | |
870 | .hw_perf_counter_enable = cpu_clock_perf_counter_enable, | |
871 | .hw_perf_counter_disable = cpu_clock_perf_counter_disable, | |
872 | .hw_perf_counter_read = cpu_clock_perf_counter_read, | |
873 | }; | |
874 | ||
bae43c99 IM |
875 | static void task_clock_perf_counter_enable(struct perf_counter *counter) |
876 | { | |
877 | } | |
878 | ||
879 | static void task_clock_perf_counter_disable(struct perf_counter *counter) | |
880 | { | |
881 | } | |
882 | ||
883 | static void task_clock_perf_counter_read(struct perf_counter *counter) | |
884 | { | |
ee06094f | 885 | atomic64_set(&counter->count, current->se.sum_exec_runtime); |
bae43c99 IM |
886 | } |
887 | ||
888 | static const struct hw_perf_counter_ops perf_ops_task_clock = { | |
889 | .hw_perf_counter_enable = task_clock_perf_counter_enable, | |
890 | .hw_perf_counter_disable = task_clock_perf_counter_disable, | |
891 | .hw_perf_counter_read = task_clock_perf_counter_read, | |
892 | }; | |
893 | ||
5c92d124 IM |
894 | static const struct hw_perf_counter_ops * |
895 | sw_perf_counter_init(struct perf_counter *counter) | |
896 | { | |
897 | const struct hw_perf_counter_ops *hw_ops = NULL; | |
898 | ||
899 | switch (counter->hw_event.type) { | |
900 | case PERF_COUNT_CPU_CLOCK: | |
901 | hw_ops = &perf_ops_cpu_clock; | |
902 | break; | |
bae43c99 IM |
903 | case PERF_COUNT_TASK_CLOCK: |
904 | hw_ops = &perf_ops_task_clock; | |
905 | break; | |
5c92d124 IM |
906 | default: |
907 | break; | |
908 | } | |
909 | return hw_ops; | |
910 | } | |
911 | ||
0793a61d TG |
912 | /* |
913 | * Allocate and initialize a counter structure | |
914 | */ | |
915 | static struct perf_counter * | |
04289bb9 IM |
916 | perf_counter_alloc(struct perf_counter_hw_event *hw_event, |
917 | int cpu, | |
918 | struct perf_counter *group_leader) | |
0793a61d | 919 | { |
5c92d124 | 920 | const struct hw_perf_counter_ops *hw_ops; |
621a01ea | 921 | struct perf_counter *counter; |
0793a61d | 922 | |
621a01ea | 923 | counter = kzalloc(sizeof(*counter), GFP_KERNEL); |
0793a61d TG |
924 | if (!counter) |
925 | return NULL; | |
926 | ||
04289bb9 IM |
927 | /* |
928 | * Single counters are their own group leaders, with an | |
929 | * empty sibling list: | |
930 | */ | |
931 | if (!group_leader) | |
932 | group_leader = counter; | |
933 | ||
0793a61d | 934 | mutex_init(&counter->mutex); |
04289bb9 IM |
935 | INIT_LIST_HEAD(&counter->list_entry); |
936 | INIT_LIST_HEAD(&counter->sibling_list); | |
0793a61d TG |
937 | init_waitqueue_head(&counter->waitq); |
938 | ||
9f66a381 IM |
939 | counter->irqdata = &counter->data[0]; |
940 | counter->usrdata = &counter->data[1]; | |
941 | counter->cpu = cpu; | |
942 | counter->hw_event = *hw_event; | |
943 | counter->wakeup_pending = 0; | |
04289bb9 | 944 | counter->group_leader = group_leader; |
621a01ea IM |
945 | counter->hw_ops = NULL; |
946 | ||
5c92d124 IM |
947 | hw_ops = NULL; |
948 | if (!hw_event->raw && hw_event->type < 0) | |
949 | hw_ops = sw_perf_counter_init(counter); | |
950 | if (!hw_ops) { | |
951 | hw_ops = hw_perf_counter_init(counter); | |
952 | } | |
953 | ||
621a01ea IM |
954 | if (!hw_ops) { |
955 | kfree(counter); | |
956 | return NULL; | |
957 | } | |
958 | counter->hw_ops = hw_ops; | |
0793a61d TG |
959 | |
960 | return counter; | |
961 | } | |
962 | ||
963 | /** | |
9f66a381 IM |
964 | * sys_perf_task_open - open a performance counter, associate it to a task/cpu |
965 | * | |
966 | * @hw_event_uptr: event type attributes for monitoring/sampling | |
0793a61d | 967 | * @pid: target pid |
9f66a381 IM |
968 | * @cpu: target cpu |
969 | * @group_fd: group leader counter fd | |
0793a61d | 970 | */ |
1d1c7ddb IM |
971 | asmlinkage int |
972 | sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user, | |
973 | pid_t pid, int cpu, int group_fd) | |
0793a61d | 974 | { |
04289bb9 | 975 | struct perf_counter *counter, *group_leader; |
9f66a381 | 976 | struct perf_counter_hw_event hw_event; |
04289bb9 IM |
977 | struct perf_counter_context *ctx; |
978 | struct file *group_file = NULL; | |
979 | int fput_needed = 0; | |
0793a61d TG |
980 | int ret; |
981 | ||
9f66a381 | 982 | if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0) |
eab656ae TG |
983 | return -EFAULT; |
984 | ||
04289bb9 | 985 | /* |
ccff286d IM |
986 | * Get the target context (task or percpu): |
987 | */ | |
988 | ctx = find_get_context(pid, cpu); | |
989 | if (IS_ERR(ctx)) | |
990 | return PTR_ERR(ctx); | |
991 | ||
992 | /* | |
993 | * Look up the group leader (we will attach this counter to it): | |
04289bb9 IM |
994 | */ |
995 | group_leader = NULL; | |
996 | if (group_fd != -1) { | |
997 | ret = -EINVAL; | |
998 | group_file = fget_light(group_fd, &fput_needed); | |
999 | if (!group_file) | |
ccff286d | 1000 | goto err_put_context; |
04289bb9 | 1001 | if (group_file->f_op != &perf_fops) |
ccff286d | 1002 | goto err_put_context; |
04289bb9 IM |
1003 | |
1004 | group_leader = group_file->private_data; | |
1005 | /* | |
ccff286d IM |
1006 | * Do not allow a recursive hierarchy (this new sibling |
1007 | * becoming part of another group-sibling): | |
1008 | */ | |
1009 | if (group_leader->group_leader != group_leader) | |
1010 | goto err_put_context; | |
1011 | /* | |
1012 | * Do not allow to attach to a group in a different | |
1013 | * task or CPU context: | |
04289bb9 | 1014 | */ |
ccff286d IM |
1015 | if (group_leader->ctx != ctx) |
1016 | goto err_put_context; | |
04289bb9 IM |
1017 | } |
1018 | ||
5c92d124 | 1019 | ret = -EINVAL; |
04289bb9 | 1020 | counter = perf_counter_alloc(&hw_event, cpu, group_leader); |
0793a61d TG |
1021 | if (!counter) |
1022 | goto err_put_context; | |
1023 | ||
0793a61d TG |
1024 | perf_install_in_context(ctx, counter, cpu); |
1025 | ||
1026 | ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0); | |
1027 | if (ret < 0) | |
1028 | goto err_remove_free_put_context; | |
1029 | ||
04289bb9 IM |
1030 | out_fput: |
1031 | fput_light(group_file, fput_needed); | |
1032 | ||
0793a61d TG |
1033 | return ret; |
1034 | ||
1035 | err_remove_free_put_context: | |
1036 | mutex_lock(&counter->mutex); | |
04289bb9 | 1037 | perf_counter_remove_from_context(counter); |
0793a61d | 1038 | mutex_unlock(&counter->mutex); |
0793a61d TG |
1039 | kfree(counter); |
1040 | ||
1041 | err_put_context: | |
1042 | put_context(ctx); | |
1043 | ||
04289bb9 | 1044 | goto out_fput; |
0793a61d TG |
1045 | } |
1046 | ||
04289bb9 | 1047 | static void __cpuinit perf_counter_init_cpu(int cpu) |
0793a61d | 1048 | { |
04289bb9 | 1049 | struct perf_cpu_context *cpuctx; |
0793a61d | 1050 | |
04289bb9 IM |
1051 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
1052 | __perf_counter_init_context(&cpuctx->ctx, NULL); | |
0793a61d TG |
1053 | |
1054 | mutex_lock(&perf_resource_mutex); | |
04289bb9 | 1055 | cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; |
0793a61d | 1056 | mutex_unlock(&perf_resource_mutex); |
04289bb9 | 1057 | |
0793a61d TG |
1058 | hw_perf_counter_setup(); |
1059 | } | |
1060 | ||
1061 | #ifdef CONFIG_HOTPLUG_CPU | |
04289bb9 | 1062 | static void __perf_counter_exit_cpu(void *info) |
0793a61d TG |
1063 | { |
1064 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); | |
1065 | struct perf_counter_context *ctx = &cpuctx->ctx; | |
1066 | struct perf_counter *counter, *tmp; | |
1067 | ||
04289bb9 IM |
1068 | list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) |
1069 | __perf_counter_remove_from_context(counter); | |
0793a61d TG |
1070 | |
1071 | } | |
04289bb9 | 1072 | static void perf_counter_exit_cpu(int cpu) |
0793a61d | 1073 | { |
04289bb9 | 1074 | smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1); |
0793a61d TG |
1075 | } |
1076 | #else | |
04289bb9 | 1077 | static inline void perf_counter_exit_cpu(int cpu) { } |
0793a61d TG |
1078 | #endif |
1079 | ||
1080 | static int __cpuinit | |
1081 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) | |
1082 | { | |
1083 | unsigned int cpu = (long)hcpu; | |
1084 | ||
1085 | switch (action) { | |
1086 | ||
1087 | case CPU_UP_PREPARE: | |
1088 | case CPU_UP_PREPARE_FROZEN: | |
04289bb9 | 1089 | perf_counter_init_cpu(cpu); |
0793a61d TG |
1090 | break; |
1091 | ||
1092 | case CPU_DOWN_PREPARE: | |
1093 | case CPU_DOWN_PREPARE_FROZEN: | |
04289bb9 | 1094 | perf_counter_exit_cpu(cpu); |
0793a61d TG |
1095 | break; |
1096 | ||
1097 | default: | |
1098 | break; | |
1099 | } | |
1100 | ||
1101 | return NOTIFY_OK; | |
1102 | } | |
1103 | ||
1104 | static struct notifier_block __cpuinitdata perf_cpu_nb = { | |
1105 | .notifier_call = perf_cpu_notify, | |
1106 | }; | |
1107 | ||
1108 | static int __init perf_counter_init(void) | |
1109 | { | |
1110 | perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, | |
1111 | (void *)(long)smp_processor_id()); | |
1112 | register_cpu_notifier(&perf_cpu_nb); | |
1113 | ||
1114 | return 0; | |
1115 | } | |
1116 | early_initcall(perf_counter_init); | |
1117 | ||
1118 | static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) | |
1119 | { | |
1120 | return sprintf(buf, "%d\n", perf_reserved_percpu); | |
1121 | } | |
1122 | ||
1123 | static ssize_t | |
1124 | perf_set_reserve_percpu(struct sysdev_class *class, | |
1125 | const char *buf, | |
1126 | size_t count) | |
1127 | { | |
1128 | struct perf_cpu_context *cpuctx; | |
1129 | unsigned long val; | |
1130 | int err, cpu, mpt; | |
1131 | ||
1132 | err = strict_strtoul(buf, 10, &val); | |
1133 | if (err) | |
1134 | return err; | |
1135 | if (val > perf_max_counters) | |
1136 | return -EINVAL; | |
1137 | ||
1138 | mutex_lock(&perf_resource_mutex); | |
1139 | perf_reserved_percpu = val; | |
1140 | for_each_online_cpu(cpu) { | |
1141 | cpuctx = &per_cpu(perf_cpu_context, cpu); | |
1142 | spin_lock_irq(&cpuctx->ctx.lock); | |
1143 | mpt = min(perf_max_counters - cpuctx->ctx.nr_counters, | |
1144 | perf_max_counters - perf_reserved_percpu); | |
1145 | cpuctx->max_pertask = mpt; | |
1146 | spin_unlock_irq(&cpuctx->ctx.lock); | |
1147 | } | |
1148 | mutex_unlock(&perf_resource_mutex); | |
1149 | ||
1150 | return count; | |
1151 | } | |
1152 | ||
1153 | static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) | |
1154 | { | |
1155 | return sprintf(buf, "%d\n", perf_overcommit); | |
1156 | } | |
1157 | ||
1158 | static ssize_t | |
1159 | perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) | |
1160 | { | |
1161 | unsigned long val; | |
1162 | int err; | |
1163 | ||
1164 | err = strict_strtoul(buf, 10, &val); | |
1165 | if (err) | |
1166 | return err; | |
1167 | if (val > 1) | |
1168 | return -EINVAL; | |
1169 | ||
1170 | mutex_lock(&perf_resource_mutex); | |
1171 | perf_overcommit = val; | |
1172 | mutex_unlock(&perf_resource_mutex); | |
1173 | ||
1174 | return count; | |
1175 | } | |
1176 | ||
1177 | static SYSDEV_CLASS_ATTR( | |
1178 | reserve_percpu, | |
1179 | 0644, | |
1180 | perf_show_reserve_percpu, | |
1181 | perf_set_reserve_percpu | |
1182 | ); | |
1183 | ||
1184 | static SYSDEV_CLASS_ATTR( | |
1185 | overcommit, | |
1186 | 0644, | |
1187 | perf_show_overcommit, | |
1188 | perf_set_overcommit | |
1189 | ); | |
1190 | ||
1191 | static struct attribute *perfclass_attrs[] = { | |
1192 | &attr_reserve_percpu.attr, | |
1193 | &attr_overcommit.attr, | |
1194 | NULL | |
1195 | }; | |
1196 | ||
1197 | static struct attribute_group perfclass_attr_group = { | |
1198 | .attrs = perfclass_attrs, | |
1199 | .name = "perf_counters", | |
1200 | }; | |
1201 | ||
1202 | static int __init perf_counter_sysfs_init(void) | |
1203 | { | |
1204 | return sysfs_create_group(&cpu_sysdev_class.kset.kobj, | |
1205 | &perfclass_attr_group); | |
1206 | } | |
1207 | device_initcall(perf_counter_sysfs_init); | |
1208 |