Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 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> |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 13 | #include <linux/file.h> |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 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> |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 21 | #include <linux/kernel_stat.h> |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 22 | #include <linux/perf_counter.h> |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 23 | #include <linux/mm.h> |
| 24 | #include <linux/vmstat.h> |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 25 | |
| 26 | /* |
| 27 | * Each CPU has a list of per CPU counters: |
| 28 | */ |
| 29 | DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); |
| 30 | |
Ingo Molnar | 088e285 | 2008-12-14 20:21:00 +0100 | [diff] [blame] | 31 | int perf_max_counters __read_mostly = 1; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 32 | static int perf_reserved_percpu __read_mostly; |
| 33 | static int perf_overcommit __read_mostly = 1; |
| 34 | |
| 35 | /* |
| 36 | * Mutex for (sysadmin-configurable) counter reservations: |
| 37 | */ |
| 38 | static DEFINE_MUTEX(perf_resource_mutex); |
| 39 | |
| 40 | /* |
| 41 | * Architecture provided APIs - weak aliases: |
| 42 | */ |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 43 | extern __weak const struct hw_perf_counter_ops * |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 44 | hw_perf_counter_init(struct perf_counter *counter) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 45 | { |
Paul Mackerras | ff6f054 | 2009-01-09 16:19:25 +1100 | [diff] [blame] | 46 | return NULL; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 47 | } |
| 48 | |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 49 | u64 __weak hw_perf_save_disable(void) { return 0; } |
Yinghai Lu | 01ea1cc | 2008-12-26 21:05:06 -0800 | [diff] [blame] | 50 | void __weak hw_perf_restore(u64 ctrl) { barrier(); } |
Paul Mackerras | 01d0287 | 2009-01-14 13:44:19 +1100 | [diff] [blame] | 51 | void __weak hw_perf_counter_setup(int cpu) { barrier(); } |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 52 | int __weak hw_perf_group_sched_in(struct perf_counter *group_leader, |
| 53 | struct perf_cpu_context *cpuctx, |
| 54 | struct perf_counter_context *ctx, int cpu) |
| 55 | { |
| 56 | return 0; |
| 57 | } |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 58 | |
Paul Mackerras | 4eb96fc | 2009-01-09 17:24:34 +1100 | [diff] [blame] | 59 | void __weak perf_counter_print_debug(void) { } |
| 60 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 61 | static void |
| 62 | list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) |
| 63 | { |
| 64 | struct perf_counter *group_leader = counter->group_leader; |
| 65 | |
| 66 | /* |
| 67 | * Depending on whether it is a standalone or sibling counter, |
| 68 | * add it straight to the context's counter list, or to the group |
| 69 | * leader's sibling list: |
| 70 | */ |
| 71 | if (counter->group_leader == counter) |
| 72 | list_add_tail(&counter->list_entry, &ctx->counter_list); |
| 73 | else |
| 74 | list_add_tail(&counter->list_entry, &group_leader->sibling_list); |
| 75 | } |
| 76 | |
| 77 | static void |
| 78 | list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) |
| 79 | { |
| 80 | struct perf_counter *sibling, *tmp; |
| 81 | |
| 82 | list_del_init(&counter->list_entry); |
| 83 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 84 | /* |
| 85 | * If this was a group counter with sibling counters then |
| 86 | * upgrade the siblings to singleton counters by adding them |
| 87 | * to the context list directly: |
| 88 | */ |
| 89 | list_for_each_entry_safe(sibling, tmp, |
| 90 | &counter->sibling_list, list_entry) { |
| 91 | |
| 92 | list_del_init(&sibling->list_entry); |
| 93 | list_add_tail(&sibling->list_entry, &ctx->counter_list); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 94 | sibling->group_leader = sibling; |
| 95 | } |
| 96 | } |
| 97 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 98 | static void |
| 99 | counter_sched_out(struct perf_counter *counter, |
| 100 | struct perf_cpu_context *cpuctx, |
| 101 | struct perf_counter_context *ctx) |
| 102 | { |
| 103 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) |
| 104 | return; |
| 105 | |
| 106 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
| 107 | counter->hw_ops->disable(counter); |
| 108 | counter->oncpu = -1; |
| 109 | |
| 110 | if (!is_software_counter(counter)) |
| 111 | cpuctx->active_oncpu--; |
| 112 | ctx->nr_active--; |
| 113 | if (counter->hw_event.exclusive || !cpuctx->active_oncpu) |
| 114 | cpuctx->exclusive = 0; |
| 115 | } |
| 116 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 117 | static void |
| 118 | group_sched_out(struct perf_counter *group_counter, |
| 119 | struct perf_cpu_context *cpuctx, |
| 120 | struct perf_counter_context *ctx) |
| 121 | { |
| 122 | struct perf_counter *counter; |
| 123 | |
| 124 | if (group_counter->state != PERF_COUNTER_STATE_ACTIVE) |
| 125 | return; |
| 126 | |
| 127 | counter_sched_out(group_counter, cpuctx, ctx); |
| 128 | |
| 129 | /* |
| 130 | * Schedule out siblings (if any): |
| 131 | */ |
| 132 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) |
| 133 | counter_sched_out(counter, cpuctx, ctx); |
| 134 | |
| 135 | if (group_counter->hw_event.exclusive) |
| 136 | cpuctx->exclusive = 0; |
| 137 | } |
| 138 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 139 | /* |
| 140 | * Cross CPU call to remove a performance counter |
| 141 | * |
| 142 | * We disable the counter on the hardware level first. After that we |
| 143 | * remove it from the context list. |
| 144 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 145 | static void __perf_counter_remove_from_context(void *info) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 146 | { |
| 147 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 148 | struct perf_counter *counter = info; |
| 149 | struct perf_counter_context *ctx = counter->ctx; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 150 | unsigned long flags; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 151 | u64 perf_flags; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 152 | |
| 153 | /* |
| 154 | * If this is a task context, we need to check whether it is |
| 155 | * the current task context of this cpu. If not it has been |
| 156 | * scheduled out before the smp call arrived. |
| 157 | */ |
| 158 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 159 | return; |
| 160 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 161 | curr_rq_lock_irq_save(&flags); |
| 162 | spin_lock(&ctx->lock); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 163 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 164 | counter_sched_out(counter, cpuctx, ctx); |
| 165 | |
| 166 | counter->task = NULL; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 167 | ctx->nr_counters--; |
| 168 | |
| 169 | /* |
| 170 | * Protect the list operation against NMI by disabling the |
| 171 | * counters on a global level. NOP for non NMI based counters. |
| 172 | */ |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 173 | perf_flags = hw_perf_save_disable(); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 174 | list_del_counter(counter, ctx); |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 175 | hw_perf_restore(perf_flags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 176 | |
| 177 | if (!ctx->task) { |
| 178 | /* |
| 179 | * Allow more per task counters with respect to the |
| 180 | * reservation: |
| 181 | */ |
| 182 | cpuctx->max_pertask = |
| 183 | min(perf_max_counters - ctx->nr_counters, |
| 184 | perf_max_counters - perf_reserved_percpu); |
| 185 | } |
| 186 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 187 | spin_unlock(&ctx->lock); |
| 188 | curr_rq_unlock_irq_restore(&flags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | |
| 192 | /* |
| 193 | * Remove the counter from a task's (or a CPU's) list of counters. |
| 194 | * |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 195 | * Must be called with counter->mutex and ctx->mutex held. |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 196 | * |
| 197 | * CPU counters are removed with a smp call. For task counters we only |
| 198 | * call when the task is on a CPU. |
| 199 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 200 | static void perf_counter_remove_from_context(struct perf_counter *counter) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 201 | { |
| 202 | struct perf_counter_context *ctx = counter->ctx; |
| 203 | struct task_struct *task = ctx->task; |
| 204 | |
| 205 | if (!task) { |
| 206 | /* |
| 207 | * Per cpu counters are removed via an smp call and |
| 208 | * the removal is always sucessful. |
| 209 | */ |
| 210 | smp_call_function_single(counter->cpu, |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 211 | __perf_counter_remove_from_context, |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 212 | counter, 1); |
| 213 | return; |
| 214 | } |
| 215 | |
| 216 | retry: |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 217 | task_oncpu_function_call(task, __perf_counter_remove_from_context, |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 218 | counter); |
| 219 | |
| 220 | spin_lock_irq(&ctx->lock); |
| 221 | /* |
| 222 | * If the context is active we need to retry the smp call. |
| 223 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 224 | if (ctx->nr_active && !list_empty(&counter->list_entry)) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 225 | spin_unlock_irq(&ctx->lock); |
| 226 | goto retry; |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * The lock prevents that this context is scheduled in so we |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 231 | * can remove the counter safely, if the call above did not |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 232 | * succeed. |
| 233 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 234 | if (!list_empty(&counter->list_entry)) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 235 | ctx->nr_counters--; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 236 | list_del_counter(counter, ctx); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 237 | counter->task = NULL; |
| 238 | } |
| 239 | spin_unlock_irq(&ctx->lock); |
| 240 | } |
| 241 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 242 | /* |
| 243 | * Cross CPU call to disable a performance counter |
| 244 | */ |
| 245 | static void __perf_counter_disable(void *info) |
| 246 | { |
| 247 | struct perf_counter *counter = info; |
| 248 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 249 | struct perf_counter_context *ctx = counter->ctx; |
| 250 | unsigned long flags; |
| 251 | |
| 252 | /* |
| 253 | * If this is a per-task counter, need to check whether this |
| 254 | * counter's task is the current task on this cpu. |
| 255 | */ |
| 256 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 257 | return; |
| 258 | |
| 259 | curr_rq_lock_irq_save(&flags); |
| 260 | spin_lock(&ctx->lock); |
| 261 | |
| 262 | /* |
| 263 | * If the counter is on, turn it off. |
| 264 | * If it is in error state, leave it in error state. |
| 265 | */ |
| 266 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { |
| 267 | if (counter == counter->group_leader) |
| 268 | group_sched_out(counter, cpuctx, ctx); |
| 269 | else |
| 270 | counter_sched_out(counter, cpuctx, ctx); |
| 271 | counter->state = PERF_COUNTER_STATE_OFF; |
| 272 | } |
| 273 | |
| 274 | spin_unlock(&ctx->lock); |
| 275 | curr_rq_unlock_irq_restore(&flags); |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Disable a counter. |
| 280 | */ |
| 281 | static void perf_counter_disable(struct perf_counter *counter) |
| 282 | { |
| 283 | struct perf_counter_context *ctx = counter->ctx; |
| 284 | struct task_struct *task = ctx->task; |
| 285 | |
| 286 | if (!task) { |
| 287 | /* |
| 288 | * Disable the counter on the cpu that it's on |
| 289 | */ |
| 290 | smp_call_function_single(counter->cpu, __perf_counter_disable, |
| 291 | counter, 1); |
| 292 | return; |
| 293 | } |
| 294 | |
| 295 | retry: |
| 296 | task_oncpu_function_call(task, __perf_counter_disable, counter); |
| 297 | |
| 298 | spin_lock_irq(&ctx->lock); |
| 299 | /* |
| 300 | * If the counter is still active, we need to retry the cross-call. |
| 301 | */ |
| 302 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { |
| 303 | spin_unlock_irq(&ctx->lock); |
| 304 | goto retry; |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * Since we have the lock this context can't be scheduled |
| 309 | * in, so we can change the state safely. |
| 310 | */ |
| 311 | if (counter->state == PERF_COUNTER_STATE_INACTIVE) |
| 312 | counter->state = PERF_COUNTER_STATE_OFF; |
| 313 | |
| 314 | spin_unlock_irq(&ctx->lock); |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * Disable a counter and all its children. |
| 319 | */ |
| 320 | static void perf_counter_disable_family(struct perf_counter *counter) |
| 321 | { |
| 322 | struct perf_counter *child; |
| 323 | |
| 324 | perf_counter_disable(counter); |
| 325 | |
| 326 | /* |
| 327 | * Lock the mutex to protect the list of children |
| 328 | */ |
| 329 | mutex_lock(&counter->mutex); |
| 330 | list_for_each_entry(child, &counter->child_list, child_list) |
| 331 | perf_counter_disable(child); |
| 332 | mutex_unlock(&counter->mutex); |
| 333 | } |
| 334 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 335 | static int |
| 336 | counter_sched_in(struct perf_counter *counter, |
| 337 | struct perf_cpu_context *cpuctx, |
| 338 | struct perf_counter_context *ctx, |
| 339 | int cpu) |
| 340 | { |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 341 | if (counter->state <= PERF_COUNTER_STATE_OFF) |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 342 | return 0; |
| 343 | |
| 344 | counter->state = PERF_COUNTER_STATE_ACTIVE; |
| 345 | counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ |
| 346 | /* |
| 347 | * The new state must be visible before we turn it on in the hardware: |
| 348 | */ |
| 349 | smp_wmb(); |
| 350 | |
| 351 | if (counter->hw_ops->enable(counter)) { |
| 352 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
| 353 | counter->oncpu = -1; |
| 354 | return -EAGAIN; |
| 355 | } |
| 356 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 357 | if (!is_software_counter(counter)) |
| 358 | cpuctx->active_oncpu++; |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 359 | ctx->nr_active++; |
| 360 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 361 | if (counter->hw_event.exclusive) |
| 362 | cpuctx->exclusive = 1; |
| 363 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 364 | return 0; |
| 365 | } |
| 366 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 367 | /* |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 368 | * Return 1 for a group consisting entirely of software counters, |
| 369 | * 0 if the group contains any hardware counters. |
| 370 | */ |
| 371 | static int is_software_only_group(struct perf_counter *leader) |
| 372 | { |
| 373 | struct perf_counter *counter; |
| 374 | |
| 375 | if (!is_software_counter(leader)) |
| 376 | return 0; |
| 377 | list_for_each_entry(counter, &leader->sibling_list, list_entry) |
| 378 | if (!is_software_counter(counter)) |
| 379 | return 0; |
| 380 | return 1; |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * Work out whether we can put this counter group on the CPU now. |
| 385 | */ |
| 386 | static int group_can_go_on(struct perf_counter *counter, |
| 387 | struct perf_cpu_context *cpuctx, |
| 388 | int can_add_hw) |
| 389 | { |
| 390 | /* |
| 391 | * Groups consisting entirely of software counters can always go on. |
| 392 | */ |
| 393 | if (is_software_only_group(counter)) |
| 394 | return 1; |
| 395 | /* |
| 396 | * If an exclusive group is already on, no other hardware |
| 397 | * counters can go on. |
| 398 | */ |
| 399 | if (cpuctx->exclusive) |
| 400 | return 0; |
| 401 | /* |
| 402 | * If this group is exclusive and there are already |
| 403 | * counters on the CPU, it can't go on. |
| 404 | */ |
| 405 | if (counter->hw_event.exclusive && cpuctx->active_oncpu) |
| 406 | return 0; |
| 407 | /* |
| 408 | * Otherwise, try to add it if all previous groups were able |
| 409 | * to go on. |
| 410 | */ |
| 411 | return can_add_hw; |
| 412 | } |
| 413 | |
| 414 | /* |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 415 | * Cross CPU call to install and enable a performance counter |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 416 | */ |
| 417 | static void __perf_install_in_context(void *info) |
| 418 | { |
| 419 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 420 | struct perf_counter *counter = info; |
| 421 | struct perf_counter_context *ctx = counter->ctx; |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 422 | struct perf_counter *leader = counter->group_leader; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 423 | int cpu = smp_processor_id(); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 424 | unsigned long flags; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 425 | u64 perf_flags; |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 426 | int err; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 427 | |
| 428 | /* |
| 429 | * If this is a task context, we need to check whether it is |
| 430 | * the current task context of this cpu. If not it has been |
| 431 | * scheduled out before the smp call arrived. |
| 432 | */ |
| 433 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 434 | return; |
| 435 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 436 | curr_rq_lock_irq_save(&flags); |
| 437 | spin_lock(&ctx->lock); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 438 | |
| 439 | /* |
| 440 | * Protect the list operation against NMI by disabling the |
| 441 | * counters on a global level. NOP for non NMI based counters. |
| 442 | */ |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 443 | perf_flags = hw_perf_save_disable(); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 444 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 445 | list_add_counter(counter, ctx); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 446 | ctx->nr_counters++; |
| 447 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 448 | /* |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 449 | * Don't put the counter on if it is disabled or if |
| 450 | * it is in a group and the group isn't on. |
| 451 | */ |
| 452 | if (counter->state != PERF_COUNTER_STATE_INACTIVE || |
| 453 | (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)) |
| 454 | goto unlock; |
| 455 | |
| 456 | /* |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 457 | * An exclusive counter can't go on if there are already active |
| 458 | * hardware counters, and no hardware counter can go on if there |
| 459 | * is already an exclusive counter on. |
| 460 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 461 | if (!group_can_go_on(counter, cpuctx, 1)) |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 462 | err = -EEXIST; |
| 463 | else |
| 464 | err = counter_sched_in(counter, cpuctx, ctx, cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 465 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 466 | if (err) { |
| 467 | /* |
| 468 | * This counter couldn't go on. If it is in a group |
| 469 | * then we have to pull the whole group off. |
| 470 | * If the counter group is pinned then put it in error state. |
| 471 | */ |
| 472 | if (leader != counter) |
| 473 | group_sched_out(leader, cpuctx, ctx); |
| 474 | if (leader->hw_event.pinned) |
| 475 | leader->state = PERF_COUNTER_STATE_ERROR; |
| 476 | } |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 477 | |
| 478 | if (!err && !ctx->task && cpuctx->max_pertask) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 479 | cpuctx->max_pertask--; |
| 480 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 481 | unlock: |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 482 | hw_perf_restore(perf_flags); |
| 483 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 484 | spin_unlock(&ctx->lock); |
| 485 | curr_rq_unlock_irq_restore(&flags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 486 | } |
| 487 | |
| 488 | /* |
| 489 | * Attach a performance counter to a context |
| 490 | * |
| 491 | * First we add the counter to the list with the hardware enable bit |
| 492 | * in counter->hw_config cleared. |
| 493 | * |
| 494 | * If the counter is attached to a task which is on a CPU we use a smp |
| 495 | * call to enable it in the task context. The task might have been |
| 496 | * scheduled away, but we check this in the smp call again. |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 497 | * |
| 498 | * Must be called with ctx->mutex held. |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 499 | */ |
| 500 | static void |
| 501 | perf_install_in_context(struct perf_counter_context *ctx, |
| 502 | struct perf_counter *counter, |
| 503 | int cpu) |
| 504 | { |
| 505 | struct task_struct *task = ctx->task; |
| 506 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 507 | if (!task) { |
| 508 | /* |
| 509 | * Per cpu counters are installed via an smp call and |
| 510 | * the install is always sucessful. |
| 511 | */ |
| 512 | smp_call_function_single(cpu, __perf_install_in_context, |
| 513 | counter, 1); |
| 514 | return; |
| 515 | } |
| 516 | |
| 517 | counter->task = task; |
| 518 | retry: |
| 519 | task_oncpu_function_call(task, __perf_install_in_context, |
| 520 | counter); |
| 521 | |
| 522 | spin_lock_irq(&ctx->lock); |
| 523 | /* |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 524 | * we need to retry the smp call. |
| 525 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 526 | if (ctx->is_active && list_empty(&counter->list_entry)) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 527 | spin_unlock_irq(&ctx->lock); |
| 528 | goto retry; |
| 529 | } |
| 530 | |
| 531 | /* |
| 532 | * The lock prevents that this context is scheduled in so we |
| 533 | * can add the counter safely, if it the call above did not |
| 534 | * succeed. |
| 535 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 536 | if (list_empty(&counter->list_entry)) { |
| 537 | list_add_counter(counter, ctx); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 538 | ctx->nr_counters++; |
| 539 | } |
| 540 | spin_unlock_irq(&ctx->lock); |
| 541 | } |
| 542 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 543 | /* |
| 544 | * Cross CPU call to enable a performance counter |
| 545 | */ |
| 546 | static void __perf_counter_enable(void *info) |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 547 | { |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 548 | struct perf_counter *counter = info; |
| 549 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 550 | struct perf_counter_context *ctx = counter->ctx; |
| 551 | struct perf_counter *leader = counter->group_leader; |
| 552 | unsigned long flags; |
| 553 | int err; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 554 | |
| 555 | /* |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 556 | * If this is a per-task counter, need to check whether this |
| 557 | * counter's task is the current task on this cpu. |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 558 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 559 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 560 | return; |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 561 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 562 | curr_rq_lock_irq_save(&flags); |
| 563 | spin_lock(&ctx->lock); |
| 564 | |
| 565 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) |
| 566 | goto unlock; |
| 567 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
| 568 | |
| 569 | /* |
| 570 | * If the counter is in a group and isn't the group leader, |
| 571 | * then don't put it on unless the group is on. |
| 572 | */ |
| 573 | if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE) |
| 574 | goto unlock; |
| 575 | |
| 576 | if (!group_can_go_on(counter, cpuctx, 1)) |
| 577 | err = -EEXIST; |
| 578 | else |
| 579 | err = counter_sched_in(counter, cpuctx, ctx, |
| 580 | smp_processor_id()); |
| 581 | |
| 582 | if (err) { |
| 583 | /* |
| 584 | * If this counter can't go on and it's part of a |
| 585 | * group, then the whole group has to come off. |
| 586 | */ |
| 587 | if (leader != counter) |
| 588 | group_sched_out(leader, cpuctx, ctx); |
| 589 | if (leader->hw_event.pinned) |
| 590 | leader->state = PERF_COUNTER_STATE_ERROR; |
| 591 | } |
| 592 | |
| 593 | unlock: |
| 594 | spin_unlock(&ctx->lock); |
| 595 | curr_rq_unlock_irq_restore(&flags); |
| 596 | } |
| 597 | |
| 598 | /* |
| 599 | * Enable a counter. |
| 600 | */ |
| 601 | static void perf_counter_enable(struct perf_counter *counter) |
| 602 | { |
| 603 | struct perf_counter_context *ctx = counter->ctx; |
| 604 | struct task_struct *task = ctx->task; |
| 605 | |
| 606 | if (!task) { |
| 607 | /* |
| 608 | * Enable the counter on the cpu that it's on |
| 609 | */ |
| 610 | smp_call_function_single(counter->cpu, __perf_counter_enable, |
| 611 | counter, 1); |
| 612 | return; |
| 613 | } |
| 614 | |
| 615 | spin_lock_irq(&ctx->lock); |
| 616 | if (counter->state >= PERF_COUNTER_STATE_INACTIVE) |
| 617 | goto out; |
| 618 | |
| 619 | /* |
| 620 | * If the counter is in error state, clear that first. |
| 621 | * That way, if we see the counter in error state below, we |
| 622 | * know that it has gone back into error state, as distinct |
| 623 | * from the task having been scheduled away before the |
| 624 | * cross-call arrived. |
| 625 | */ |
| 626 | if (counter->state == PERF_COUNTER_STATE_ERROR) |
| 627 | counter->state = PERF_COUNTER_STATE_OFF; |
| 628 | |
| 629 | retry: |
| 630 | spin_unlock_irq(&ctx->lock); |
| 631 | task_oncpu_function_call(task, __perf_counter_enable, counter); |
| 632 | |
| 633 | spin_lock_irq(&ctx->lock); |
| 634 | |
| 635 | /* |
| 636 | * If the context is active and the counter is still off, |
| 637 | * we need to retry the cross-call. |
| 638 | */ |
| 639 | if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF) |
| 640 | goto retry; |
| 641 | |
| 642 | /* |
| 643 | * Since we have the lock this context can't be scheduled |
| 644 | * in, so we can change the state safely. |
| 645 | */ |
| 646 | if (counter->state == PERF_COUNTER_STATE_OFF) |
| 647 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
| 648 | out: |
| 649 | spin_unlock_irq(&ctx->lock); |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * Enable a counter and all its children. |
| 654 | */ |
| 655 | static void perf_counter_enable_family(struct perf_counter *counter) |
| 656 | { |
| 657 | struct perf_counter *child; |
| 658 | |
| 659 | perf_counter_enable(counter); |
| 660 | |
| 661 | /* |
| 662 | * Lock the mutex to protect the list of children |
| 663 | */ |
| 664 | mutex_lock(&counter->mutex); |
| 665 | list_for_each_entry(child, &counter->child_list, child_list) |
| 666 | perf_counter_enable(child); |
| 667 | mutex_unlock(&counter->mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 668 | } |
| 669 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 670 | void __perf_counter_sched_out(struct perf_counter_context *ctx, |
| 671 | struct perf_cpu_context *cpuctx) |
| 672 | { |
| 673 | struct perf_counter *counter; |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 674 | u64 flags; |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 675 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 676 | spin_lock(&ctx->lock); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 677 | ctx->is_active = 0; |
| 678 | if (likely(!ctx->nr_counters)) |
| 679 | goto out; |
| 680 | |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 681 | flags = hw_perf_save_disable(); |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 682 | if (ctx->nr_active) { |
| 683 | list_for_each_entry(counter, &ctx->counter_list, list_entry) |
| 684 | group_sched_out(counter, cpuctx, ctx); |
| 685 | } |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 686 | hw_perf_restore(flags); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 687 | out: |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 688 | spin_unlock(&ctx->lock); |
| 689 | } |
| 690 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 691 | /* |
| 692 | * Called from scheduler to remove the counters of the current task, |
| 693 | * with interrupts disabled. |
| 694 | * |
| 695 | * We stop each counter and update the counter value in counter->count. |
| 696 | * |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 697 | * This does not protect us against NMI, but disable() |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 698 | * sets the disabled bit in the control field of counter _before_ |
| 699 | * accessing the counter control register. If a NMI hits, then it will |
| 700 | * not restart the counter. |
| 701 | */ |
| 702 | void perf_counter_task_sched_out(struct task_struct *task, int cpu) |
| 703 | { |
| 704 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 705 | struct perf_counter_context *ctx = &task->perf_counter_ctx; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 706 | |
| 707 | if (likely(!cpuctx->task_ctx)) |
| 708 | return; |
| 709 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 710 | __perf_counter_sched_out(ctx, cpuctx); |
| 711 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 712 | cpuctx->task_ctx = NULL; |
| 713 | } |
| 714 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 715 | static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx) |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 716 | { |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 717 | __perf_counter_sched_out(&cpuctx->ctx, cpuctx); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 718 | } |
| 719 | |
Ingo Molnar | 7995888 | 2008-12-17 08:54:56 +0100 | [diff] [blame] | 720 | static int |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 721 | group_sched_in(struct perf_counter *group_counter, |
| 722 | struct perf_cpu_context *cpuctx, |
| 723 | struct perf_counter_context *ctx, |
| 724 | int cpu) |
| 725 | { |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 726 | struct perf_counter *counter, *partial_group; |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 727 | int ret; |
| 728 | |
| 729 | if (group_counter->state == PERF_COUNTER_STATE_OFF) |
| 730 | return 0; |
| 731 | |
| 732 | ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu); |
| 733 | if (ret) |
| 734 | return ret < 0 ? ret : 0; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 735 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 736 | if (counter_sched_in(group_counter, cpuctx, ctx, cpu)) |
| 737 | return -EAGAIN; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 738 | |
| 739 | /* |
| 740 | * Schedule in siblings as one group (if any): |
| 741 | */ |
Ingo Molnar | 7995888 | 2008-12-17 08:54:56 +0100 | [diff] [blame] | 742 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 743 | if (counter_sched_in(counter, cpuctx, ctx, cpu)) { |
| 744 | partial_group = counter; |
| 745 | goto group_error; |
| 746 | } |
Ingo Molnar | 7995888 | 2008-12-17 08:54:56 +0100 | [diff] [blame] | 747 | } |
| 748 | |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 749 | return 0; |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 750 | |
| 751 | group_error: |
| 752 | /* |
| 753 | * Groups can be scheduled in as one unit only, so undo any |
| 754 | * partial group before returning: |
| 755 | */ |
| 756 | list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { |
| 757 | if (counter == partial_group) |
| 758 | break; |
| 759 | counter_sched_out(counter, cpuctx, ctx); |
| 760 | } |
| 761 | counter_sched_out(group_counter, cpuctx, ctx); |
| 762 | |
| 763 | return -EAGAIN; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 764 | } |
| 765 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 766 | static void |
| 767 | __perf_counter_sched_in(struct perf_counter_context *ctx, |
| 768 | struct perf_cpu_context *cpuctx, int cpu) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 769 | { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 770 | struct perf_counter *counter; |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 771 | u64 flags; |
Paul Mackerras | dd0e6ba | 2009-01-12 15:11:00 +1100 | [diff] [blame] | 772 | int can_add_hw = 1; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 773 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 774 | spin_lock(&ctx->lock); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 775 | ctx->is_active = 1; |
| 776 | if (likely(!ctx->nr_counters)) |
| 777 | goto out; |
| 778 | |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 779 | flags = hw_perf_save_disable(); |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 780 | |
| 781 | /* |
| 782 | * First go through the list and put on any pinned groups |
| 783 | * in order to give them the best chance of going on. |
| 784 | */ |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 785 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 786 | if (counter->state <= PERF_COUNTER_STATE_OFF || |
| 787 | !counter->hw_event.pinned) |
| 788 | continue; |
| 789 | if (counter->cpu != -1 && counter->cpu != cpu) |
| 790 | continue; |
| 791 | |
| 792 | if (group_can_go_on(counter, cpuctx, 1)) |
| 793 | group_sched_in(counter, cpuctx, ctx, cpu); |
| 794 | |
| 795 | /* |
| 796 | * If this pinned group hasn't been scheduled, |
| 797 | * put it in error state. |
| 798 | */ |
| 799 | if (counter->state == PERF_COUNTER_STATE_INACTIVE) |
| 800 | counter->state = PERF_COUNTER_STATE_ERROR; |
| 801 | } |
| 802 | |
| 803 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
| 804 | /* |
| 805 | * Ignore counters in OFF or ERROR state, and |
| 806 | * ignore pinned counters since we did them already. |
| 807 | */ |
| 808 | if (counter->state <= PERF_COUNTER_STATE_OFF || |
| 809 | counter->hw_event.pinned) |
| 810 | continue; |
| 811 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 812 | /* |
| 813 | * Listen to the 'cpu' scheduling filter constraint |
| 814 | * of counters: |
| 815 | */ |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 816 | if (counter->cpu != -1 && counter->cpu != cpu) |
| 817 | continue; |
| 818 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 819 | if (group_can_go_on(counter, cpuctx, can_add_hw)) { |
Paul Mackerras | dd0e6ba | 2009-01-12 15:11:00 +1100 | [diff] [blame] | 820 | if (group_sched_in(counter, cpuctx, ctx, cpu)) |
| 821 | can_add_hw = 0; |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 822 | } |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 823 | } |
Paul Mackerras | 3cbed42 | 2009-01-09 16:43:42 +1100 | [diff] [blame] | 824 | hw_perf_restore(flags); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 825 | out: |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 826 | spin_unlock(&ctx->lock); |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 827 | } |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 828 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 829 | /* |
| 830 | * Called from scheduler to add the counters of the current task |
| 831 | * with interrupts disabled. |
| 832 | * |
| 833 | * We restore the counter value and then enable it. |
| 834 | * |
| 835 | * This does not protect us against NMI, but enable() |
| 836 | * sets the enabled bit in the control field of counter _before_ |
| 837 | * accessing the counter control register. If a NMI hits, then it will |
| 838 | * keep the counter running. |
| 839 | */ |
| 840 | void perf_counter_task_sched_in(struct task_struct *task, int cpu) |
| 841 | { |
| 842 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 843 | struct perf_counter_context *ctx = &task->perf_counter_ctx; |
| 844 | |
| 845 | __perf_counter_sched_in(ctx, cpuctx, cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 846 | cpuctx->task_ctx = ctx; |
| 847 | } |
| 848 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 849 | static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) |
| 850 | { |
| 851 | struct perf_counter_context *ctx = &cpuctx->ctx; |
| 852 | |
| 853 | __perf_counter_sched_in(ctx, cpuctx, cpu); |
| 854 | } |
| 855 | |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 856 | int perf_counter_task_disable(void) |
| 857 | { |
| 858 | struct task_struct *curr = current; |
| 859 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; |
| 860 | struct perf_counter *counter; |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 861 | unsigned long flags; |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 862 | u64 perf_flags; |
| 863 | int cpu; |
| 864 | |
| 865 | if (likely(!ctx->nr_counters)) |
| 866 | return 0; |
| 867 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 868 | curr_rq_lock_irq_save(&flags); |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 869 | cpu = smp_processor_id(); |
| 870 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 871 | /* force the update of the task clock: */ |
| 872 | __task_delta_exec(curr, 1); |
| 873 | |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 874 | perf_counter_task_sched_out(curr, cpu); |
| 875 | |
| 876 | spin_lock(&ctx->lock); |
| 877 | |
| 878 | /* |
| 879 | * Disable all the counters: |
| 880 | */ |
| 881 | perf_flags = hw_perf_save_disable(); |
| 882 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 883 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
| 884 | if (counter->state != PERF_COUNTER_STATE_ERROR) |
| 885 | counter->state = PERF_COUNTER_STATE_OFF; |
| 886 | } |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 887 | |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 888 | hw_perf_restore(perf_flags); |
| 889 | |
| 890 | spin_unlock(&ctx->lock); |
| 891 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 892 | curr_rq_unlock_irq_restore(&flags); |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 893 | |
| 894 | return 0; |
| 895 | } |
| 896 | |
| 897 | int perf_counter_task_enable(void) |
| 898 | { |
| 899 | struct task_struct *curr = current; |
| 900 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; |
| 901 | struct perf_counter *counter; |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 902 | unsigned long flags; |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 903 | u64 perf_flags; |
| 904 | int cpu; |
| 905 | |
| 906 | if (likely(!ctx->nr_counters)) |
| 907 | return 0; |
| 908 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 909 | curr_rq_lock_irq_save(&flags); |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 910 | cpu = smp_processor_id(); |
| 911 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 912 | /* force the update of the task clock: */ |
| 913 | __task_delta_exec(curr, 1); |
| 914 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 915 | perf_counter_task_sched_out(curr, cpu); |
| 916 | |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 917 | spin_lock(&ctx->lock); |
| 918 | |
| 919 | /* |
| 920 | * Disable all the counters: |
| 921 | */ |
| 922 | perf_flags = hw_perf_save_disable(); |
| 923 | |
| 924 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 925 | if (counter->state > PERF_COUNTER_STATE_OFF) |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 926 | continue; |
Ingo Molnar | 6a93070 | 2008-12-11 15:17:03 +0100 | [diff] [blame] | 927 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 928 | counter->hw_event.disabled = 0; |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 929 | } |
| 930 | hw_perf_restore(perf_flags); |
| 931 | |
| 932 | spin_unlock(&ctx->lock); |
| 933 | |
| 934 | perf_counter_task_sched_in(curr, cpu); |
| 935 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 936 | curr_rq_unlock_irq_restore(&flags); |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 937 | |
| 938 | return 0; |
| 939 | } |
| 940 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 941 | /* |
| 942 | * Round-robin a context's counters: |
| 943 | */ |
| 944 | static void rotate_ctx(struct perf_counter_context *ctx) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 945 | { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 946 | struct perf_counter *counter; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 947 | u64 perf_flags; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 948 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 949 | if (!ctx->nr_counters) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 950 | return; |
| 951 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 952 | spin_lock(&ctx->lock); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 953 | /* |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 954 | * Rotate the first entry last (works just fine for group counters too): |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 955 | */ |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 956 | perf_flags = hw_perf_save_disable(); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 957 | list_for_each_entry(counter, &ctx->counter_list, list_entry) { |
| 958 | list_del(&counter->list_entry); |
| 959 | list_add_tail(&counter->list_entry, &ctx->counter_list); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 960 | break; |
| 961 | } |
Ingo Molnar | 01b2838 | 2008-12-11 13:45:51 +0100 | [diff] [blame] | 962 | hw_perf_restore(perf_flags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 963 | |
| 964 | spin_unlock(&ctx->lock); |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 965 | } |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 966 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 967 | void perf_counter_task_tick(struct task_struct *curr, int cpu) |
| 968 | { |
| 969 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 970 | struct perf_counter_context *ctx = &curr->perf_counter_ctx; |
| 971 | const int rotate_percpu = 0; |
| 972 | |
| 973 | if (rotate_percpu) |
| 974 | perf_counter_cpu_sched_out(cpuctx); |
| 975 | perf_counter_task_sched_out(curr, cpu); |
| 976 | |
| 977 | if (rotate_percpu) |
| 978 | rotate_ctx(&cpuctx->ctx); |
| 979 | rotate_ctx(ctx); |
| 980 | |
| 981 | if (rotate_percpu) |
| 982 | perf_counter_cpu_sched_in(cpuctx, cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 983 | perf_counter_task_sched_in(curr, cpu); |
| 984 | } |
| 985 | |
| 986 | /* |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 987 | * Cross CPU call to read the hardware counter |
| 988 | */ |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 989 | static void __read(void *info) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 990 | { |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 991 | struct perf_counter *counter = info; |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 992 | unsigned long flags; |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 993 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 994 | curr_rq_lock_irq_save(&flags); |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 995 | counter->hw_ops->read(counter); |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 996 | curr_rq_unlock_irq_restore(&flags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 997 | } |
| 998 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 999 | static u64 perf_counter_read(struct perf_counter *counter) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1000 | { |
| 1001 | /* |
| 1002 | * If counter is enabled and currently active on a CPU, update the |
| 1003 | * value in the counter structure: |
| 1004 | */ |
Ingo Molnar | 6a93070 | 2008-12-11 15:17:03 +0100 | [diff] [blame] | 1005 | if (counter->state == PERF_COUNTER_STATE_ACTIVE) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1006 | smp_call_function_single(counter->oncpu, |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1007 | __read, counter, 1); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1008 | } |
| 1009 | |
Ingo Molnar | ee06094 | 2008-12-13 09:00:03 +0100 | [diff] [blame] | 1010 | return atomic64_read(&counter->count); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1011 | } |
| 1012 | |
| 1013 | /* |
| 1014 | * Cross CPU call to switch performance data pointers |
| 1015 | */ |
| 1016 | static void __perf_switch_irq_data(void *info) |
| 1017 | { |
| 1018 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1019 | struct perf_counter *counter = info; |
| 1020 | struct perf_counter_context *ctx = counter->ctx; |
| 1021 | struct perf_data *oldirqdata = counter->irqdata; |
| 1022 | |
| 1023 | /* |
| 1024 | * If this is a task context, we need to check whether it is |
| 1025 | * the current task context of this cpu. If not it has been |
| 1026 | * scheduled out before the smp call arrived. |
| 1027 | */ |
| 1028 | if (ctx->task) { |
| 1029 | if (cpuctx->task_ctx != ctx) |
| 1030 | return; |
| 1031 | spin_lock(&ctx->lock); |
| 1032 | } |
| 1033 | |
| 1034 | /* Change the pointer NMI safe */ |
| 1035 | atomic_long_set((atomic_long_t *)&counter->irqdata, |
| 1036 | (unsigned long) counter->usrdata); |
| 1037 | counter->usrdata = oldirqdata; |
| 1038 | |
| 1039 | if (ctx->task) |
| 1040 | spin_unlock(&ctx->lock); |
| 1041 | } |
| 1042 | |
| 1043 | static struct perf_data *perf_switch_irq_data(struct perf_counter *counter) |
| 1044 | { |
| 1045 | struct perf_counter_context *ctx = counter->ctx; |
| 1046 | struct perf_data *oldirqdata = counter->irqdata; |
| 1047 | struct task_struct *task = ctx->task; |
| 1048 | |
| 1049 | if (!task) { |
| 1050 | smp_call_function_single(counter->cpu, |
| 1051 | __perf_switch_irq_data, |
| 1052 | counter, 1); |
| 1053 | return counter->usrdata; |
| 1054 | } |
| 1055 | |
| 1056 | retry: |
| 1057 | spin_lock_irq(&ctx->lock); |
Ingo Molnar | 6a93070 | 2008-12-11 15:17:03 +0100 | [diff] [blame] | 1058 | if (counter->state != PERF_COUNTER_STATE_ACTIVE) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1059 | counter->irqdata = counter->usrdata; |
| 1060 | counter->usrdata = oldirqdata; |
| 1061 | spin_unlock_irq(&ctx->lock); |
| 1062 | return oldirqdata; |
| 1063 | } |
| 1064 | spin_unlock_irq(&ctx->lock); |
| 1065 | task_oncpu_function_call(task, __perf_switch_irq_data, counter); |
| 1066 | /* Might have failed, because task was scheduled out */ |
| 1067 | if (counter->irqdata == oldirqdata) |
| 1068 | goto retry; |
| 1069 | |
| 1070 | return counter->usrdata; |
| 1071 | } |
| 1072 | |
| 1073 | static void put_context(struct perf_counter_context *ctx) |
| 1074 | { |
| 1075 | if (ctx->task) |
| 1076 | put_task_struct(ctx->task); |
| 1077 | } |
| 1078 | |
| 1079 | static struct perf_counter_context *find_get_context(pid_t pid, int cpu) |
| 1080 | { |
| 1081 | struct perf_cpu_context *cpuctx; |
| 1082 | struct perf_counter_context *ctx; |
| 1083 | struct task_struct *task; |
| 1084 | |
| 1085 | /* |
| 1086 | * If cpu is not a wildcard then this is a percpu counter: |
| 1087 | */ |
| 1088 | if (cpu != -1) { |
| 1089 | /* Must be root to operate on a CPU counter: */ |
| 1090 | if (!capable(CAP_SYS_ADMIN)) |
| 1091 | return ERR_PTR(-EACCES); |
| 1092 | |
| 1093 | if (cpu < 0 || cpu > num_possible_cpus()) |
| 1094 | return ERR_PTR(-EINVAL); |
| 1095 | |
| 1096 | /* |
| 1097 | * We could be clever and allow to attach a counter to an |
| 1098 | * offline CPU and activate it when the CPU comes up, but |
| 1099 | * that's for later. |
| 1100 | */ |
| 1101 | if (!cpu_isset(cpu, cpu_online_map)) |
| 1102 | return ERR_PTR(-ENODEV); |
| 1103 | |
| 1104 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 1105 | ctx = &cpuctx->ctx; |
| 1106 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1107 | return ctx; |
| 1108 | } |
| 1109 | |
| 1110 | rcu_read_lock(); |
| 1111 | if (!pid) |
| 1112 | task = current; |
| 1113 | else |
| 1114 | task = find_task_by_vpid(pid); |
| 1115 | if (task) |
| 1116 | get_task_struct(task); |
| 1117 | rcu_read_unlock(); |
| 1118 | |
| 1119 | if (!task) |
| 1120 | return ERR_PTR(-ESRCH); |
| 1121 | |
| 1122 | ctx = &task->perf_counter_ctx; |
| 1123 | ctx->task = task; |
| 1124 | |
| 1125 | /* Reuse ptrace permission checks for now. */ |
| 1126 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) { |
| 1127 | put_context(ctx); |
| 1128 | return ERR_PTR(-EACCES); |
| 1129 | } |
| 1130 | |
| 1131 | return ctx; |
| 1132 | } |
| 1133 | |
| 1134 | /* |
| 1135 | * Called when the last reference to the file is gone. |
| 1136 | */ |
| 1137 | static int perf_release(struct inode *inode, struct file *file) |
| 1138 | { |
| 1139 | struct perf_counter *counter = file->private_data; |
| 1140 | struct perf_counter_context *ctx = counter->ctx; |
| 1141 | |
| 1142 | file->private_data = NULL; |
| 1143 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1144 | mutex_lock(&ctx->mutex); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1145 | mutex_lock(&counter->mutex); |
| 1146 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1147 | perf_counter_remove_from_context(counter); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1148 | |
| 1149 | mutex_unlock(&counter->mutex); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1150 | mutex_unlock(&ctx->mutex); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1151 | |
| 1152 | kfree(counter); |
Mike Galbraith | 5af7591 | 2009-02-11 10:53:37 +0100 | [diff] [blame] | 1153 | put_context(ctx); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1154 | |
| 1155 | return 0; |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * Read the performance counter - simple non blocking version for now |
| 1160 | */ |
| 1161 | static ssize_t |
| 1162 | perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) |
| 1163 | { |
| 1164 | u64 cntval; |
| 1165 | |
| 1166 | if (count != sizeof(cntval)) |
| 1167 | return -EINVAL; |
| 1168 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1169 | /* |
| 1170 | * Return end-of-file for a read on a counter that is in |
| 1171 | * error state (i.e. because it was pinned but it couldn't be |
| 1172 | * scheduled on to the CPU at some point). |
| 1173 | */ |
| 1174 | if (counter->state == PERF_COUNTER_STATE_ERROR) |
| 1175 | return 0; |
| 1176 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1177 | mutex_lock(&counter->mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1178 | cntval = perf_counter_read(counter); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1179 | mutex_unlock(&counter->mutex); |
| 1180 | |
| 1181 | return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval); |
| 1182 | } |
| 1183 | |
| 1184 | static ssize_t |
| 1185 | perf_copy_usrdata(struct perf_data *usrdata, char __user *buf, size_t count) |
| 1186 | { |
| 1187 | if (!usrdata->len) |
| 1188 | return 0; |
| 1189 | |
| 1190 | count = min(count, (size_t)usrdata->len); |
| 1191 | if (copy_to_user(buf, usrdata->data + usrdata->rd_idx, count)) |
| 1192 | return -EFAULT; |
| 1193 | |
| 1194 | /* Adjust the counters */ |
| 1195 | usrdata->len -= count; |
| 1196 | if (!usrdata->len) |
| 1197 | usrdata->rd_idx = 0; |
| 1198 | else |
| 1199 | usrdata->rd_idx += count; |
| 1200 | |
| 1201 | return count; |
| 1202 | } |
| 1203 | |
| 1204 | static ssize_t |
| 1205 | perf_read_irq_data(struct perf_counter *counter, |
| 1206 | char __user *buf, |
| 1207 | size_t count, |
| 1208 | int nonblocking) |
| 1209 | { |
| 1210 | struct perf_data *irqdata, *usrdata; |
| 1211 | DECLARE_WAITQUEUE(wait, current); |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1212 | ssize_t res, res2; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1213 | |
| 1214 | irqdata = counter->irqdata; |
| 1215 | usrdata = counter->usrdata; |
| 1216 | |
| 1217 | if (usrdata->len + irqdata->len >= count) |
| 1218 | goto read_pending; |
| 1219 | |
| 1220 | if (nonblocking) |
| 1221 | return -EAGAIN; |
| 1222 | |
| 1223 | spin_lock_irq(&counter->waitq.lock); |
| 1224 | __add_wait_queue(&counter->waitq, &wait); |
| 1225 | for (;;) { |
| 1226 | set_current_state(TASK_INTERRUPTIBLE); |
| 1227 | if (usrdata->len + irqdata->len >= count) |
| 1228 | break; |
| 1229 | |
| 1230 | if (signal_pending(current)) |
| 1231 | break; |
| 1232 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1233 | if (counter->state == PERF_COUNTER_STATE_ERROR) |
| 1234 | break; |
| 1235 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1236 | spin_unlock_irq(&counter->waitq.lock); |
| 1237 | schedule(); |
| 1238 | spin_lock_irq(&counter->waitq.lock); |
| 1239 | } |
| 1240 | __remove_wait_queue(&counter->waitq, &wait); |
| 1241 | __set_current_state(TASK_RUNNING); |
| 1242 | spin_unlock_irq(&counter->waitq.lock); |
| 1243 | |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1244 | if (usrdata->len + irqdata->len < count && |
| 1245 | counter->state != PERF_COUNTER_STATE_ERROR) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1246 | return -ERESTARTSYS; |
| 1247 | read_pending: |
| 1248 | mutex_lock(&counter->mutex); |
| 1249 | |
| 1250 | /* Drain pending data first: */ |
| 1251 | res = perf_copy_usrdata(usrdata, buf, count); |
| 1252 | if (res < 0 || res == count) |
| 1253 | goto out; |
| 1254 | |
| 1255 | /* Switch irq buffer: */ |
| 1256 | usrdata = perf_switch_irq_data(counter); |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1257 | res2 = perf_copy_usrdata(usrdata, buf + res, count - res); |
| 1258 | if (res2 < 0) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1259 | if (!res) |
| 1260 | res = -EFAULT; |
| 1261 | } else { |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1262 | res += res2; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1263 | } |
| 1264 | out: |
| 1265 | mutex_unlock(&counter->mutex); |
| 1266 | |
| 1267 | return res; |
| 1268 | } |
| 1269 | |
| 1270 | static ssize_t |
| 1271 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 1272 | { |
| 1273 | struct perf_counter *counter = file->private_data; |
| 1274 | |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1275 | switch (counter->hw_event.record_type) { |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1276 | case PERF_RECORD_SIMPLE: |
| 1277 | return perf_read_hw(counter, buf, count); |
| 1278 | |
| 1279 | case PERF_RECORD_IRQ: |
| 1280 | case PERF_RECORD_GROUP: |
| 1281 | return perf_read_irq_data(counter, buf, count, |
| 1282 | file->f_flags & O_NONBLOCK); |
| 1283 | } |
| 1284 | return -EINVAL; |
| 1285 | } |
| 1286 | |
| 1287 | static unsigned int perf_poll(struct file *file, poll_table *wait) |
| 1288 | { |
| 1289 | struct perf_counter *counter = file->private_data; |
| 1290 | unsigned int events = 0; |
| 1291 | unsigned long flags; |
| 1292 | |
| 1293 | poll_wait(file, &counter->waitq, wait); |
| 1294 | |
| 1295 | spin_lock_irqsave(&counter->waitq.lock, flags); |
| 1296 | if (counter->usrdata->len || counter->irqdata->len) |
| 1297 | events |= POLLIN; |
| 1298 | spin_unlock_irqrestore(&counter->waitq.lock, flags); |
| 1299 | |
| 1300 | return events; |
| 1301 | } |
| 1302 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1303 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 1304 | { |
| 1305 | struct perf_counter *counter = file->private_data; |
| 1306 | int err = 0; |
| 1307 | |
| 1308 | switch (cmd) { |
| 1309 | case PERF_COUNTER_IOC_ENABLE: |
| 1310 | perf_counter_enable_family(counter); |
| 1311 | break; |
| 1312 | case PERF_COUNTER_IOC_DISABLE: |
| 1313 | perf_counter_disable_family(counter); |
| 1314 | break; |
| 1315 | default: |
| 1316 | err = -ENOTTY; |
| 1317 | } |
| 1318 | return err; |
| 1319 | } |
| 1320 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1321 | static const struct file_operations perf_fops = { |
| 1322 | .release = perf_release, |
| 1323 | .read = perf_read, |
| 1324 | .poll = perf_poll, |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1325 | .unlocked_ioctl = perf_ioctl, |
| 1326 | .compat_ioctl = perf_ioctl, |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1327 | }; |
| 1328 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1329 | static int cpu_clock_perf_counter_enable(struct perf_counter *counter) |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1330 | { |
Paul Mackerras | 9abf8a0 | 2009-01-09 16:26:43 +1100 | [diff] [blame] | 1331 | int cpu = raw_smp_processor_id(); |
| 1332 | |
| 1333 | atomic64_set(&counter->hw.prev_count, cpu_clock(cpu)); |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1334 | return 0; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1335 | } |
| 1336 | |
Paul Mackerras | 9abf8a0 | 2009-01-09 16:26:43 +1100 | [diff] [blame] | 1337 | static void cpu_clock_perf_counter_update(struct perf_counter *counter) |
| 1338 | { |
| 1339 | int cpu = raw_smp_processor_id(); |
| 1340 | s64 prev; |
| 1341 | u64 now; |
| 1342 | |
| 1343 | now = cpu_clock(cpu); |
| 1344 | prev = atomic64_read(&counter->hw.prev_count); |
| 1345 | atomic64_set(&counter->hw.prev_count, now); |
| 1346 | atomic64_add(now - prev, &counter->count); |
| 1347 | } |
| 1348 | |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1349 | static void cpu_clock_perf_counter_disable(struct perf_counter *counter) |
| 1350 | { |
Paul Mackerras | 9abf8a0 | 2009-01-09 16:26:43 +1100 | [diff] [blame] | 1351 | cpu_clock_perf_counter_update(counter); |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1352 | } |
| 1353 | |
| 1354 | static void cpu_clock_perf_counter_read(struct perf_counter *counter) |
| 1355 | { |
Paul Mackerras | 9abf8a0 | 2009-01-09 16:26:43 +1100 | [diff] [blame] | 1356 | cpu_clock_perf_counter_update(counter); |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1357 | } |
| 1358 | |
| 1359 | static const struct hw_perf_counter_ops perf_ops_cpu_clock = { |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1360 | .enable = cpu_clock_perf_counter_enable, |
| 1361 | .disable = cpu_clock_perf_counter_disable, |
| 1362 | .read = cpu_clock_perf_counter_read, |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1363 | }; |
| 1364 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1365 | /* |
| 1366 | * Called from within the scheduler: |
| 1367 | */ |
| 1368 | static u64 task_clock_perf_counter_val(struct perf_counter *counter, int update) |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1369 | { |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1370 | struct task_struct *curr = counter->task; |
| 1371 | u64 delta; |
| 1372 | |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1373 | delta = __task_delta_exec(curr, update); |
| 1374 | |
| 1375 | return curr->se.sum_exec_runtime + delta; |
| 1376 | } |
| 1377 | |
| 1378 | static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now) |
| 1379 | { |
| 1380 | u64 prev; |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1381 | s64 delta; |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1382 | |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1383 | prev = atomic64_read(&counter->hw.prev_count); |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1384 | |
| 1385 | atomic64_set(&counter->hw.prev_count, now); |
| 1386 | |
| 1387 | delta = now - prev; |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1388 | |
| 1389 | atomic64_add(delta, &counter->count); |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1390 | } |
| 1391 | |
| 1392 | static void task_clock_perf_counter_read(struct perf_counter *counter) |
| 1393 | { |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1394 | u64 now = task_clock_perf_counter_val(counter, 1); |
| 1395 | |
| 1396 | task_clock_perf_counter_update(counter, now); |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1397 | } |
| 1398 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1399 | static int task_clock_perf_counter_enable(struct perf_counter *counter) |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1400 | { |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1401 | u64 now = task_clock_perf_counter_val(counter, 0); |
| 1402 | |
| 1403 | atomic64_set(&counter->hw.prev_count, now); |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1404 | |
| 1405 | return 0; |
Ingo Molnar | 8cb391e | 2008-12-14 12:22:31 +0100 | [diff] [blame] | 1406 | } |
| 1407 | |
| 1408 | static void task_clock_perf_counter_disable(struct perf_counter *counter) |
| 1409 | { |
Ingo Molnar | aa9c4c0 | 2008-12-17 14:10:57 +0100 | [diff] [blame] | 1410 | u64 now = task_clock_perf_counter_val(counter, 0); |
| 1411 | |
| 1412 | task_clock_perf_counter_update(counter, now); |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1413 | } |
| 1414 | |
| 1415 | static const struct hw_perf_counter_ops perf_ops_task_clock = { |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1416 | .enable = task_clock_perf_counter_enable, |
| 1417 | .disable = task_clock_perf_counter_disable, |
| 1418 | .read = task_clock_perf_counter_read, |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1419 | }; |
| 1420 | |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1421 | #ifdef CONFIG_VM_EVENT_COUNTERS |
| 1422 | #define cpu_page_faults() __get_cpu_var(vm_event_states).event[PGFAULT] |
| 1423 | #else |
| 1424 | #define cpu_page_faults() 0 |
| 1425 | #endif |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1426 | |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1427 | static u64 get_page_faults(struct perf_counter *counter) |
| 1428 | { |
| 1429 | struct task_struct *curr = counter->ctx->task; |
| 1430 | |
| 1431 | if (curr) |
| 1432 | return curr->maj_flt + curr->min_flt; |
| 1433 | return cpu_page_faults(); |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1434 | } |
| 1435 | |
| 1436 | static void page_faults_perf_counter_update(struct perf_counter *counter) |
| 1437 | { |
| 1438 | u64 prev, now; |
| 1439 | s64 delta; |
| 1440 | |
| 1441 | prev = atomic64_read(&counter->hw.prev_count); |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1442 | now = get_page_faults(counter); |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1443 | |
| 1444 | atomic64_set(&counter->hw.prev_count, now); |
| 1445 | |
| 1446 | delta = now - prev; |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1447 | |
| 1448 | atomic64_add(delta, &counter->count); |
| 1449 | } |
| 1450 | |
| 1451 | static void page_faults_perf_counter_read(struct perf_counter *counter) |
| 1452 | { |
| 1453 | page_faults_perf_counter_update(counter); |
| 1454 | } |
| 1455 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1456 | static int page_faults_perf_counter_enable(struct perf_counter *counter) |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1457 | { |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1458 | atomic64_set(&counter->hw.prev_count, get_page_faults(counter)); |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1459 | return 0; |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1460 | } |
| 1461 | |
| 1462 | static void page_faults_perf_counter_disable(struct perf_counter *counter) |
| 1463 | { |
| 1464 | page_faults_perf_counter_update(counter); |
| 1465 | } |
| 1466 | |
| 1467 | static const struct hw_perf_counter_ops perf_ops_page_faults = { |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1468 | .enable = page_faults_perf_counter_enable, |
| 1469 | .disable = page_faults_perf_counter_disable, |
| 1470 | .read = page_faults_perf_counter_read, |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1471 | }; |
| 1472 | |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1473 | static u64 get_context_switches(struct perf_counter *counter) |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1474 | { |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1475 | struct task_struct *curr = counter->ctx->task; |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1476 | |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1477 | if (curr) |
| 1478 | return curr->nvcsw + curr->nivcsw; |
| 1479 | return cpu_nr_switches(smp_processor_id()); |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1480 | } |
| 1481 | |
| 1482 | static void context_switches_perf_counter_update(struct perf_counter *counter) |
| 1483 | { |
| 1484 | u64 prev, now; |
| 1485 | s64 delta; |
| 1486 | |
| 1487 | prev = atomic64_read(&counter->hw.prev_count); |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1488 | now = get_context_switches(counter); |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1489 | |
| 1490 | atomic64_set(&counter->hw.prev_count, now); |
| 1491 | |
| 1492 | delta = now - prev; |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1493 | |
| 1494 | atomic64_add(delta, &counter->count); |
| 1495 | } |
| 1496 | |
| 1497 | static void context_switches_perf_counter_read(struct perf_counter *counter) |
| 1498 | { |
| 1499 | context_switches_perf_counter_update(counter); |
| 1500 | } |
| 1501 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1502 | static int context_switches_perf_counter_enable(struct perf_counter *counter) |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1503 | { |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1504 | atomic64_set(&counter->hw.prev_count, get_context_switches(counter)); |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1505 | return 0; |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1506 | } |
| 1507 | |
| 1508 | static void context_switches_perf_counter_disable(struct perf_counter *counter) |
| 1509 | { |
| 1510 | context_switches_perf_counter_update(counter); |
| 1511 | } |
| 1512 | |
| 1513 | static const struct hw_perf_counter_ops perf_ops_context_switches = { |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1514 | .enable = context_switches_perf_counter_enable, |
| 1515 | .disable = context_switches_perf_counter_disable, |
| 1516 | .read = context_switches_perf_counter_read, |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1517 | }; |
| 1518 | |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1519 | static inline u64 get_cpu_migrations(struct perf_counter *counter) |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1520 | { |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1521 | struct task_struct *curr = counter->ctx->task; |
| 1522 | |
| 1523 | if (curr) |
| 1524 | return curr->se.nr_migrations; |
| 1525 | return cpu_nr_migrations(smp_processor_id()); |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1526 | } |
| 1527 | |
| 1528 | static void cpu_migrations_perf_counter_update(struct perf_counter *counter) |
| 1529 | { |
| 1530 | u64 prev, now; |
| 1531 | s64 delta; |
| 1532 | |
| 1533 | prev = atomic64_read(&counter->hw.prev_count); |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1534 | now = get_cpu_migrations(counter); |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1535 | |
| 1536 | atomic64_set(&counter->hw.prev_count, now); |
| 1537 | |
| 1538 | delta = now - prev; |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1539 | |
| 1540 | atomic64_add(delta, &counter->count); |
| 1541 | } |
| 1542 | |
| 1543 | static void cpu_migrations_perf_counter_read(struct perf_counter *counter) |
| 1544 | { |
| 1545 | cpu_migrations_perf_counter_update(counter); |
| 1546 | } |
| 1547 | |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1548 | static int cpu_migrations_perf_counter_enable(struct perf_counter *counter) |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1549 | { |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1550 | atomic64_set(&counter->hw.prev_count, get_cpu_migrations(counter)); |
Ingo Molnar | 95cdd2e | 2008-12-21 13:50:42 +0100 | [diff] [blame] | 1551 | return 0; |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1552 | } |
| 1553 | |
| 1554 | static void cpu_migrations_perf_counter_disable(struct perf_counter *counter) |
| 1555 | { |
| 1556 | cpu_migrations_perf_counter_update(counter); |
| 1557 | } |
| 1558 | |
| 1559 | static const struct hw_perf_counter_ops perf_ops_cpu_migrations = { |
Ingo Molnar | 7671581 | 2008-12-17 14:20:28 +0100 | [diff] [blame] | 1560 | .enable = cpu_migrations_perf_counter_enable, |
| 1561 | .disable = cpu_migrations_perf_counter_disable, |
| 1562 | .read = cpu_migrations_perf_counter_read, |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1563 | }; |
| 1564 | |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1565 | static const struct hw_perf_counter_ops * |
| 1566 | sw_perf_counter_init(struct perf_counter *counter) |
| 1567 | { |
| 1568 | const struct hw_perf_counter_ops *hw_ops = NULL; |
| 1569 | |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1570 | /* |
| 1571 | * Software counters (currently) can't in general distinguish |
| 1572 | * between user, kernel and hypervisor events. |
| 1573 | * However, context switches and cpu migrations are considered |
| 1574 | * to be kernel events, and page faults are never hypervisor |
| 1575 | * events. |
| 1576 | */ |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1577 | switch (counter->hw_event.type) { |
| 1578 | case PERF_COUNT_CPU_CLOCK: |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1579 | if (!(counter->hw_event.exclude_user || |
| 1580 | counter->hw_event.exclude_kernel || |
| 1581 | counter->hw_event.exclude_hv)) |
| 1582 | hw_ops = &perf_ops_cpu_clock; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1583 | break; |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1584 | case PERF_COUNT_TASK_CLOCK: |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1585 | if (counter->hw_event.exclude_user || |
| 1586 | counter->hw_event.exclude_kernel || |
| 1587 | counter->hw_event.exclude_hv) |
| 1588 | break; |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1589 | /* |
| 1590 | * If the user instantiates this as a per-cpu counter, |
| 1591 | * use the cpu_clock counter instead. |
| 1592 | */ |
| 1593 | if (counter->ctx->task) |
| 1594 | hw_ops = &perf_ops_task_clock; |
| 1595 | else |
| 1596 | hw_ops = &perf_ops_cpu_clock; |
Ingo Molnar | bae43c9 | 2008-12-11 14:03:20 +0100 | [diff] [blame] | 1597 | break; |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1598 | case PERF_COUNT_PAGE_FAULTS: |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1599 | if (!(counter->hw_event.exclude_user || |
| 1600 | counter->hw_event.exclude_kernel)) |
| 1601 | hw_ops = &perf_ops_page_faults; |
Ingo Molnar | e06c61a | 2008-12-14 14:44:31 +0100 | [diff] [blame] | 1602 | break; |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1603 | case PERF_COUNT_CONTEXT_SWITCHES: |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1604 | if (!counter->hw_event.exclude_kernel) |
| 1605 | hw_ops = &perf_ops_context_switches; |
Ingo Molnar | 5d6a27d | 2008-12-14 12:28:33 +0100 | [diff] [blame] | 1606 | break; |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1607 | case PERF_COUNT_CPU_MIGRATIONS: |
Paul Mackerras | 0475f9e | 2009-02-11 14:35:35 +1100 | [diff] [blame] | 1608 | if (!counter->hw_event.exclude_kernel) |
| 1609 | hw_ops = &perf_ops_cpu_migrations; |
Ingo Molnar | 6c594c2 | 2008-12-14 12:34:15 +0100 | [diff] [blame] | 1610 | break; |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1611 | default: |
| 1612 | break; |
| 1613 | } |
| 1614 | return hw_ops; |
| 1615 | } |
| 1616 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1617 | /* |
| 1618 | * Allocate and initialize a counter structure |
| 1619 | */ |
| 1620 | static struct perf_counter * |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1621 | perf_counter_alloc(struct perf_counter_hw_event *hw_event, |
| 1622 | int cpu, |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1623 | struct perf_counter_context *ctx, |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1624 | struct perf_counter *group_leader, |
| 1625 | gfp_t gfpflags) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1626 | { |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1627 | const struct hw_perf_counter_ops *hw_ops; |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 1628 | struct perf_counter *counter; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1629 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1630 | counter = kzalloc(sizeof(*counter), gfpflags); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1631 | if (!counter) |
| 1632 | return NULL; |
| 1633 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1634 | /* |
| 1635 | * Single counters are their own group leaders, with an |
| 1636 | * empty sibling list: |
| 1637 | */ |
| 1638 | if (!group_leader) |
| 1639 | group_leader = counter; |
| 1640 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1641 | mutex_init(&counter->mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1642 | INIT_LIST_HEAD(&counter->list_entry); |
| 1643 | INIT_LIST_HEAD(&counter->sibling_list); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1644 | init_waitqueue_head(&counter->waitq); |
| 1645 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1646 | INIT_LIST_HEAD(&counter->child_list); |
| 1647 | |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1648 | counter->irqdata = &counter->data[0]; |
| 1649 | counter->usrdata = &counter->data[1]; |
| 1650 | counter->cpu = cpu; |
| 1651 | counter->hw_event = *hw_event; |
| 1652 | counter->wakeup_pending = 0; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1653 | counter->group_leader = group_leader; |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 1654 | counter->hw_ops = NULL; |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1655 | counter->ctx = ctx; |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 1656 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 1657 | counter->state = PERF_COUNTER_STATE_INACTIVE; |
Ingo Molnar | a86ed50 | 2008-12-17 00:43:10 +0100 | [diff] [blame] | 1658 | if (hw_event->disabled) |
| 1659 | counter->state = PERF_COUNTER_STATE_OFF; |
| 1660 | |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1661 | hw_ops = NULL; |
| 1662 | if (!hw_event->raw && hw_event->type < 0) |
| 1663 | hw_ops = sw_perf_counter_init(counter); |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1664 | else |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1665 | hw_ops = hw_perf_counter_init(counter); |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1666 | |
Ingo Molnar | 621a01e | 2008-12-11 12:46:46 +0100 | [diff] [blame] | 1667 | if (!hw_ops) { |
| 1668 | kfree(counter); |
| 1669 | return NULL; |
| 1670 | } |
| 1671 | counter->hw_ops = hw_ops; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1672 | |
| 1673 | return counter; |
| 1674 | } |
| 1675 | |
| 1676 | /** |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1677 | * sys_perf_task_open - open a performance counter, associate it to a task/cpu |
| 1678 | * |
| 1679 | * @hw_event_uptr: event type attributes for monitoring/sampling |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1680 | * @pid: target pid |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1681 | * @cpu: target cpu |
| 1682 | * @group_fd: group leader counter fd |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1683 | */ |
Ingo Molnar | 1d1c7dd | 2008-12-11 14:59:31 +0100 | [diff] [blame] | 1684 | asmlinkage int |
| 1685 | sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user, |
| 1686 | pid_t pid, int cpu, int group_fd) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1687 | { |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1688 | struct perf_counter *counter, *group_leader; |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1689 | struct perf_counter_hw_event hw_event; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1690 | struct perf_counter_context *ctx; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1691 | struct file *counter_file = NULL; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1692 | struct file *group_file = NULL; |
| 1693 | int fput_needed = 0; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1694 | int fput_needed2 = 0; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1695 | int ret; |
| 1696 | |
Ingo Molnar | 9f66a38 | 2008-12-10 12:33:23 +0100 | [diff] [blame] | 1697 | if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0) |
Thomas Gleixner | eab656a | 2008-12-08 19:26:59 +0100 | [diff] [blame] | 1698 | return -EFAULT; |
| 1699 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1700 | /* |
Ingo Molnar | ccff286 | 2008-12-11 11:26:29 +0100 | [diff] [blame] | 1701 | * Get the target context (task or percpu): |
| 1702 | */ |
| 1703 | ctx = find_get_context(pid, cpu); |
| 1704 | if (IS_ERR(ctx)) |
| 1705 | return PTR_ERR(ctx); |
| 1706 | |
| 1707 | /* |
| 1708 | * Look up the group leader (we will attach this counter to it): |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1709 | */ |
| 1710 | group_leader = NULL; |
| 1711 | if (group_fd != -1) { |
| 1712 | ret = -EINVAL; |
| 1713 | group_file = fget_light(group_fd, &fput_needed); |
| 1714 | if (!group_file) |
Ingo Molnar | ccff286 | 2008-12-11 11:26:29 +0100 | [diff] [blame] | 1715 | goto err_put_context; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1716 | if (group_file->f_op != &perf_fops) |
Ingo Molnar | ccff286 | 2008-12-11 11:26:29 +0100 | [diff] [blame] | 1717 | goto err_put_context; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1718 | |
| 1719 | group_leader = group_file->private_data; |
| 1720 | /* |
Ingo Molnar | ccff286 | 2008-12-11 11:26:29 +0100 | [diff] [blame] | 1721 | * Do not allow a recursive hierarchy (this new sibling |
| 1722 | * becoming part of another group-sibling): |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1723 | */ |
Ingo Molnar | ccff286 | 2008-12-11 11:26:29 +0100 | [diff] [blame] | 1724 | if (group_leader->group_leader != group_leader) |
| 1725 | goto err_put_context; |
| 1726 | /* |
| 1727 | * Do not allow to attach to a group in a different |
| 1728 | * task or CPU context: |
| 1729 | */ |
| 1730 | if (group_leader->ctx != ctx) |
| 1731 | goto err_put_context; |
Paul Mackerras | 3b6f9e5 | 2009-01-14 21:00:30 +1100 | [diff] [blame] | 1732 | /* |
| 1733 | * Only a group leader can be exclusive or pinned |
| 1734 | */ |
| 1735 | if (hw_event.exclusive || hw_event.pinned) |
| 1736 | goto err_put_context; |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1737 | } |
| 1738 | |
Ingo Molnar | 5c92d12 | 2008-12-11 13:21:10 +0100 | [diff] [blame] | 1739 | ret = -EINVAL; |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1740 | counter = perf_counter_alloc(&hw_event, cpu, ctx, group_leader, |
| 1741 | GFP_KERNEL); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1742 | if (!counter) |
| 1743 | goto err_put_context; |
| 1744 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1745 | ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0); |
| 1746 | if (ret < 0) |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1747 | goto err_free_put_context; |
| 1748 | |
| 1749 | counter_file = fget_light(ret, &fput_needed2); |
| 1750 | if (!counter_file) |
| 1751 | goto err_free_put_context; |
| 1752 | |
| 1753 | counter->filp = counter_file; |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1754 | mutex_lock(&ctx->mutex); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1755 | perf_install_in_context(ctx, counter, cpu); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1756 | mutex_unlock(&ctx->mutex); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1757 | |
| 1758 | fput_light(counter_file, fput_needed2); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1759 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1760 | out_fput: |
| 1761 | fput_light(group_file, fput_needed); |
| 1762 | |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1763 | return ret; |
| 1764 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1765 | err_free_put_context: |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1766 | kfree(counter); |
| 1767 | |
| 1768 | err_put_context: |
| 1769 | put_context(ctx); |
| 1770 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 1771 | goto out_fput; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 1772 | } |
| 1773 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1774 | /* |
| 1775 | * Initialize the perf_counter context in a task_struct: |
| 1776 | */ |
| 1777 | static void |
| 1778 | __perf_counter_init_context(struct perf_counter_context *ctx, |
| 1779 | struct task_struct *task) |
| 1780 | { |
| 1781 | memset(ctx, 0, sizeof(*ctx)); |
| 1782 | spin_lock_init(&ctx->lock); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1783 | mutex_init(&ctx->mutex); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1784 | INIT_LIST_HEAD(&ctx->counter_list); |
| 1785 | ctx->task = task; |
| 1786 | } |
| 1787 | |
| 1788 | /* |
| 1789 | * inherit a counter from parent task to child task: |
| 1790 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1791 | static struct perf_counter * |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1792 | inherit_counter(struct perf_counter *parent_counter, |
| 1793 | struct task_struct *parent, |
| 1794 | struct perf_counter_context *parent_ctx, |
| 1795 | struct task_struct *child, |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1796 | struct perf_counter *group_leader, |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1797 | struct perf_counter_context *child_ctx) |
| 1798 | { |
| 1799 | struct perf_counter *child_counter; |
| 1800 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1801 | /* |
| 1802 | * Instead of creating recursive hierarchies of counters, |
| 1803 | * we link inherited counters back to the original parent, |
| 1804 | * which has a filp for sure, which we use as the reference |
| 1805 | * count: |
| 1806 | */ |
| 1807 | if (parent_counter->parent) |
| 1808 | parent_counter = parent_counter->parent; |
| 1809 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1810 | child_counter = perf_counter_alloc(&parent_counter->hw_event, |
Paul Mackerras | 23a185c | 2009-02-09 22:42:47 +1100 | [diff] [blame] | 1811 | parent_counter->cpu, child_ctx, |
| 1812 | group_leader, GFP_KERNEL); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1813 | if (!child_counter) |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1814 | return NULL; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1815 | |
| 1816 | /* |
| 1817 | * Link it up in the child's context: |
| 1818 | */ |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1819 | child_counter->task = child; |
| 1820 | list_add_counter(child_counter, child_ctx); |
| 1821 | child_ctx->nr_counters++; |
| 1822 | |
| 1823 | child_counter->parent = parent_counter; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1824 | /* |
| 1825 | * inherit into child's child as well: |
| 1826 | */ |
| 1827 | child_counter->hw_event.inherit = 1; |
| 1828 | |
| 1829 | /* |
| 1830 | * Get a reference to the parent filp - we will fput it |
| 1831 | * when the child counter exits. This is safe to do because |
| 1832 | * we are in the parent and we know that the filp still |
| 1833 | * exists and has a nonzero count: |
| 1834 | */ |
| 1835 | atomic_long_inc(&parent_counter->filp->f_count); |
| 1836 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1837 | /* |
| 1838 | * Link this into the parent counter's child list |
| 1839 | */ |
| 1840 | mutex_lock(&parent_counter->mutex); |
| 1841 | list_add_tail(&child_counter->child_list, &parent_counter->child_list); |
| 1842 | |
| 1843 | /* |
| 1844 | * Make the child state follow the state of the parent counter, |
| 1845 | * not its hw_event.disabled bit. We hold the parent's mutex, |
| 1846 | * so we won't race with perf_counter_{en,dis}able_family. |
| 1847 | */ |
| 1848 | if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE) |
| 1849 | child_counter->state = PERF_COUNTER_STATE_INACTIVE; |
| 1850 | else |
| 1851 | child_counter->state = PERF_COUNTER_STATE_OFF; |
| 1852 | |
| 1853 | mutex_unlock(&parent_counter->mutex); |
| 1854 | |
| 1855 | return child_counter; |
| 1856 | } |
| 1857 | |
| 1858 | static int inherit_group(struct perf_counter *parent_counter, |
| 1859 | struct task_struct *parent, |
| 1860 | struct perf_counter_context *parent_ctx, |
| 1861 | struct task_struct *child, |
| 1862 | struct perf_counter_context *child_ctx) |
| 1863 | { |
| 1864 | struct perf_counter *leader; |
| 1865 | struct perf_counter *sub; |
| 1866 | |
| 1867 | leader = inherit_counter(parent_counter, parent, parent_ctx, |
| 1868 | child, NULL, child_ctx); |
| 1869 | if (!leader) |
| 1870 | return -ENOMEM; |
| 1871 | list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) { |
| 1872 | if (!inherit_counter(sub, parent, parent_ctx, |
| 1873 | child, leader, child_ctx)) |
| 1874 | return -ENOMEM; |
| 1875 | } |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1876 | return 0; |
| 1877 | } |
| 1878 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1879 | static void sync_child_counter(struct perf_counter *child_counter, |
| 1880 | struct perf_counter *parent_counter) |
| 1881 | { |
| 1882 | u64 parent_val, child_val; |
| 1883 | |
| 1884 | parent_val = atomic64_read(&parent_counter->count); |
| 1885 | child_val = atomic64_read(&child_counter->count); |
| 1886 | |
| 1887 | /* |
| 1888 | * Add back the child's count to the parent's count: |
| 1889 | */ |
| 1890 | atomic64_add(child_val, &parent_counter->count); |
| 1891 | |
| 1892 | /* |
| 1893 | * Remove this counter from the parent's list |
| 1894 | */ |
| 1895 | mutex_lock(&parent_counter->mutex); |
| 1896 | list_del_init(&child_counter->child_list); |
| 1897 | mutex_unlock(&parent_counter->mutex); |
| 1898 | |
| 1899 | /* |
| 1900 | * Release the parent counter, if this was the last |
| 1901 | * reference to it. |
| 1902 | */ |
| 1903 | fput(parent_counter->filp); |
| 1904 | } |
| 1905 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1906 | static void |
| 1907 | __perf_counter_exit_task(struct task_struct *child, |
| 1908 | struct perf_counter *child_counter, |
| 1909 | struct perf_counter_context *child_ctx) |
| 1910 | { |
| 1911 | struct perf_counter *parent_counter; |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1912 | struct perf_counter *sub, *tmp; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1913 | |
| 1914 | /* |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 1915 | * If we do not self-reap then we have to wait for the |
| 1916 | * child task to unschedule (it will happen for sure), |
| 1917 | * so that its counter is at its final count. (This |
| 1918 | * condition triggers rarely - child tasks usually get |
| 1919 | * off their CPU before the parent has a chance to |
| 1920 | * get this far into the reaping action) |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1921 | */ |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 1922 | if (child != current) { |
| 1923 | wait_task_inactive(child, 0); |
| 1924 | list_del_init(&child_counter->list_entry); |
| 1925 | } else { |
Ingo Molnar | 0cc0c02 | 2008-12-14 23:20:36 +0100 | [diff] [blame] | 1926 | struct perf_cpu_context *cpuctx; |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 1927 | unsigned long flags; |
| 1928 | u64 perf_flags; |
| 1929 | |
| 1930 | /* |
| 1931 | * Disable and unlink this counter. |
| 1932 | * |
| 1933 | * Be careful about zapping the list - IRQ/NMI context |
| 1934 | * could still be processing it: |
| 1935 | */ |
| 1936 | curr_rq_lock_irq_save(&flags); |
| 1937 | perf_flags = hw_perf_save_disable(); |
Ingo Molnar | 0cc0c02 | 2008-12-14 23:20:36 +0100 | [diff] [blame] | 1938 | |
| 1939 | cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1940 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1941 | group_sched_out(child_counter, cpuctx, child_ctx); |
Ingo Molnar | 0cc0c02 | 2008-12-14 23:20:36 +0100 | [diff] [blame] | 1942 | |
Ingo Molnar | 235c7fc | 2008-12-21 14:43:25 +0100 | [diff] [blame] | 1943 | list_del_init(&child_counter->list_entry); |
| 1944 | |
| 1945 | child_ctx->nr_counters--; |
| 1946 | |
| 1947 | hw_perf_restore(perf_flags); |
| 1948 | curr_rq_unlock_irq_restore(&flags); |
Ingo Molnar | 0cc0c02 | 2008-12-14 23:20:36 +0100 | [diff] [blame] | 1949 | } |
| 1950 | |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1951 | parent_counter = child_counter->parent; |
| 1952 | /* |
| 1953 | * It can happen that parent exits first, and has counters |
| 1954 | * that are still around due to the child reference. These |
| 1955 | * counters need to be zapped - but otherwise linger. |
| 1956 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1957 | if (parent_counter) { |
| 1958 | sync_child_counter(child_counter, parent_counter); |
| 1959 | list_for_each_entry_safe(sub, tmp, &child_counter->sibling_list, |
| 1960 | list_entry) { |
Paul Mackerras | 4bcf349 | 2009-02-11 13:53:19 +0100 | [diff] [blame^] | 1961 | if (sub->parent) { |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1962 | sync_child_counter(sub, sub->parent); |
Paul Mackerras | 4bcf349 | 2009-02-11 13:53:19 +0100 | [diff] [blame^] | 1963 | kfree(sub); |
| 1964 | } |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1965 | } |
Mike Galbraith | 65d3708 | 2009-01-29 14:06:52 +0100 | [diff] [blame] | 1966 | kfree(child_counter); |
Paul Mackerras | 4bcf349 | 2009-02-11 13:53:19 +0100 | [diff] [blame^] | 1967 | } |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1968 | } |
| 1969 | |
| 1970 | /* |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1971 | * When a child task exits, feed back counter values to parent counters. |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1972 | * |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1973 | * Note: we may be running in child context, but the PID is not hashed |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1974 | * anymore so new counters will not be added. |
| 1975 | */ |
| 1976 | void perf_counter_exit_task(struct task_struct *child) |
| 1977 | { |
| 1978 | struct perf_counter *child_counter, *tmp; |
| 1979 | struct perf_counter_context *child_ctx; |
| 1980 | |
| 1981 | child_ctx = &child->perf_counter_ctx; |
| 1982 | |
| 1983 | if (likely(!child_ctx->nr_counters)) |
| 1984 | return; |
| 1985 | |
| 1986 | list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, |
| 1987 | list_entry) |
| 1988 | __perf_counter_exit_task(child, child_counter, child_ctx); |
| 1989 | } |
| 1990 | |
| 1991 | /* |
| 1992 | * Initialize the perf_counter context in task_struct |
| 1993 | */ |
| 1994 | void perf_counter_init_task(struct task_struct *child) |
| 1995 | { |
| 1996 | struct perf_counter_context *child_ctx, *parent_ctx; |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 1997 | struct perf_counter *counter; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1998 | struct task_struct *parent = current; |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 1999 | |
| 2000 | child_ctx = &child->perf_counter_ctx; |
| 2001 | parent_ctx = &parent->perf_counter_ctx; |
| 2002 | |
| 2003 | __perf_counter_init_context(child_ctx, child); |
| 2004 | |
| 2005 | /* |
| 2006 | * This is executed from the parent task context, so inherit |
| 2007 | * counters that have been marked for cloning: |
| 2008 | */ |
| 2009 | |
| 2010 | if (likely(!parent_ctx->nr_counters)) |
| 2011 | return; |
| 2012 | |
| 2013 | /* |
| 2014 | * Lock the parent list. No need to lock the child - not PID |
| 2015 | * hashed yet and not running, so nobody can access it. |
| 2016 | */ |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2017 | mutex_lock(&parent_ctx->mutex); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 2018 | |
| 2019 | /* |
| 2020 | * We dont have to disable NMIs - we are only looking at |
| 2021 | * the list, not manipulating it: |
| 2022 | */ |
| 2023 | list_for_each_entry(counter, &parent_ctx->counter_list, list_entry) { |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2024 | if (!counter->hw_event.inherit) |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 2025 | continue; |
| 2026 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2027 | if (inherit_group(counter, parent, |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 2028 | parent_ctx, child, child_ctx)) |
| 2029 | break; |
| 2030 | } |
| 2031 | |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2032 | mutex_unlock(&parent_ctx->mutex); |
Ingo Molnar | 9b51f66 | 2008-12-12 13:49:45 +0100 | [diff] [blame] | 2033 | } |
| 2034 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2035 | static void __cpuinit perf_counter_init_cpu(int cpu) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2036 | { |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2037 | struct perf_cpu_context *cpuctx; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2038 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2039 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 2040 | __perf_counter_init_context(&cpuctx->ctx, NULL); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2041 | |
| 2042 | mutex_lock(&perf_resource_mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2043 | cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2044 | mutex_unlock(&perf_resource_mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2045 | |
Paul Mackerras | 01d0287 | 2009-01-14 13:44:19 +1100 | [diff] [blame] | 2046 | hw_perf_counter_setup(cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2047 | } |
| 2048 | |
| 2049 | #ifdef CONFIG_HOTPLUG_CPU |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2050 | static void __perf_counter_exit_cpu(void *info) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2051 | { |
| 2052 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 2053 | struct perf_counter_context *ctx = &cpuctx->ctx; |
| 2054 | struct perf_counter *counter, *tmp; |
| 2055 | |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2056 | list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) |
| 2057 | __perf_counter_remove_from_context(counter); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2058 | } |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2059 | static void perf_counter_exit_cpu(int cpu) |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2060 | { |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2061 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 2062 | struct perf_counter_context *ctx = &cpuctx->ctx; |
| 2063 | |
| 2064 | mutex_lock(&ctx->mutex); |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2065 | smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1); |
Paul Mackerras | d859e29 | 2009-01-17 18:10:22 +1100 | [diff] [blame] | 2066 | mutex_unlock(&ctx->mutex); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2067 | } |
| 2068 | #else |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2069 | static inline void perf_counter_exit_cpu(int cpu) { } |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2070 | #endif |
| 2071 | |
| 2072 | static int __cpuinit |
| 2073 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
| 2074 | { |
| 2075 | unsigned int cpu = (long)hcpu; |
| 2076 | |
| 2077 | switch (action) { |
| 2078 | |
| 2079 | case CPU_UP_PREPARE: |
| 2080 | case CPU_UP_PREPARE_FROZEN: |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2081 | perf_counter_init_cpu(cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2082 | break; |
| 2083 | |
| 2084 | case CPU_DOWN_PREPARE: |
| 2085 | case CPU_DOWN_PREPARE_FROZEN: |
Ingo Molnar | 04289bb | 2008-12-11 08:38:42 +0100 | [diff] [blame] | 2086 | perf_counter_exit_cpu(cpu); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 2087 | break; |
| 2088 | |
| 2089 | default: |
| 2090 | break; |
| 2091 | } |
| 2092 | |
| 2093 | return NOTIFY_OK; |
| 2094 | } |
| 2095 | |
| 2096 | static struct notifier_block __cpuinitdata perf_cpu_nb = { |
| 2097 | .notifier_call = perf_cpu_notify, |
| 2098 | }; |
| 2099 | |
| 2100 | static int __init perf_counter_init(void) |
| 2101 | { |
| 2102 | perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, |
| 2103 | (void *)(long)smp_processor_id()); |
| 2104 | register_cpu_notifier(&perf_cpu_nb); |
| 2105 | |
| 2106 | return 0; |
| 2107 | } |
| 2108 | early_initcall(perf_counter_init); |
| 2109 | |
| 2110 | static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) |
| 2111 | { |
| 2112 | return sprintf(buf, "%d\n", perf_reserved_percpu); |
| 2113 | } |
| 2114 | |
| 2115 | static ssize_t |
| 2116 | perf_set_reserve_percpu(struct sysdev_class *class, |
| 2117 | const char *buf, |
| 2118 | size_t count) |
| 2119 | { |
| 2120 | struct perf_cpu_context *cpuctx; |
| 2121 | unsigned long val; |
| 2122 | int err, cpu, mpt; |
| 2123 | |
| 2124 | err = strict_strtoul(buf, 10, &val); |
| 2125 | if (err) |
| 2126 | return err; |
| 2127 | if (val > perf_max_counters) |
| 2128 | return -EINVAL; |
| 2129 | |
| 2130 | mutex_lock(&perf_resource_mutex); |
| 2131 | perf_reserved_percpu = val; |
| 2132 | for_each_online_cpu(cpu) { |
| 2133 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 2134 | spin_lock_irq(&cpuctx->ctx.lock); |
| 2135 | mpt = min(perf_max_counters - cpuctx->ctx.nr_counters, |
| 2136 | perf_max_counters - perf_reserved_percpu); |
| 2137 | cpuctx->max_pertask = mpt; |
| 2138 | spin_unlock_irq(&cpuctx->ctx.lock); |
| 2139 | } |
| 2140 | mutex_unlock(&perf_resource_mutex); |
| 2141 | |
| 2142 | return count; |
| 2143 | } |
| 2144 | |
| 2145 | static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) |
| 2146 | { |
| 2147 | return sprintf(buf, "%d\n", perf_overcommit); |
| 2148 | } |
| 2149 | |
| 2150 | static ssize_t |
| 2151 | perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) |
| 2152 | { |
| 2153 | unsigned long val; |
| 2154 | int err; |
| 2155 | |
| 2156 | err = strict_strtoul(buf, 10, &val); |
| 2157 | if (err) |
| 2158 | return err; |
| 2159 | if (val > 1) |
| 2160 | return -EINVAL; |
| 2161 | |
| 2162 | mutex_lock(&perf_resource_mutex); |
| 2163 | perf_overcommit = val; |
| 2164 | mutex_unlock(&perf_resource_mutex); |
| 2165 | |
| 2166 | return count; |
| 2167 | } |
| 2168 | |
| 2169 | static SYSDEV_CLASS_ATTR( |
| 2170 | reserve_percpu, |
| 2171 | 0644, |
| 2172 | perf_show_reserve_percpu, |
| 2173 | perf_set_reserve_percpu |
| 2174 | ); |
| 2175 | |
| 2176 | static SYSDEV_CLASS_ATTR( |
| 2177 | overcommit, |
| 2178 | 0644, |
| 2179 | perf_show_overcommit, |
| 2180 | perf_set_overcommit |
| 2181 | ); |
| 2182 | |
| 2183 | static struct attribute *perfclass_attrs[] = { |
| 2184 | &attr_reserve_percpu.attr, |
| 2185 | &attr_overcommit.attr, |
| 2186 | NULL |
| 2187 | }; |
| 2188 | |
| 2189 | static struct attribute_group perfclass_attr_group = { |
| 2190 | .attrs = perfclass_attrs, |
| 2191 | .name = "perf_counters", |
| 2192 | }; |
| 2193 | |
| 2194 | static int __init perf_counter_sysfs_init(void) |
| 2195 | { |
| 2196 | return sysfs_create_group(&cpu_sysdev_class.kset.kobj, |
| 2197 | &perfclass_attr_group); |
| 2198 | } |
| 2199 | device_initcall(perf_counter_sysfs_init); |