Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/profile.c |
| 3 | * Simple profiling. Manages a direct-mapped profile hit count buffer, |
| 4 | * with configurable resolution, support for restricting the cpus on |
| 5 | * which profiling is done, and switching between cpu time and |
| 6 | * schedule() calls via kernel command line parameters passed at boot. |
| 7 | * |
| 8 | * Scheduler profiling support, Arjan van de Ven and Ingo Molnar, |
| 9 | * Red Hat, July 2004 |
| 10 | * Consolidation of architecture support code for profiling, |
| 11 | * William Irwin, Oracle, July 2004 |
| 12 | * Amortized hit count accounting via per-cpu open-addressed hashtables |
| 13 | * to resolve timer interrupt livelocks, William Irwin, Oracle, 2004 |
| 14 | */ |
| 15 | |
| 16 | #include <linux/config.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/profile.h> |
| 19 | #include <linux/bootmem.h> |
| 20 | #include <linux/notifier.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <linux/cpumask.h> |
| 23 | #include <linux/cpu.h> |
| 24 | #include <linux/profile.h> |
| 25 | #include <linux/highmem.h> |
| 26 | #include <asm/sections.h> |
| 27 | #include <asm/semaphore.h> |
| 28 | |
| 29 | struct profile_hit { |
| 30 | u32 pc, hits; |
| 31 | }; |
| 32 | #define PROFILE_GRPSHIFT 3 |
| 33 | #define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) |
| 34 | #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) |
| 35 | #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) |
| 36 | |
| 37 | /* Oprofile timer tick hook */ |
Christoph Lameter | 6c03652 | 2005-07-07 17:56:59 -0700 | [diff] [blame] | 38 | int (*timer_hook)(struct pt_regs *) __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | static atomic_t *prof_buffer; |
| 41 | static unsigned long prof_len, prof_shift; |
Christoph Lameter | 6c03652 | 2005-07-07 17:56:59 -0700 | [diff] [blame] | 42 | static int prof_on __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | static cpumask_t prof_cpu_mask = CPU_MASK_ALL; |
| 44 | #ifdef CONFIG_SMP |
| 45 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); |
| 46 | static DEFINE_PER_CPU(int, cpu_profile_flip); |
| 47 | static DECLARE_MUTEX(profile_flip_mutex); |
| 48 | #endif /* CONFIG_SMP */ |
| 49 | |
| 50 | static int __init profile_setup(char * str) |
| 51 | { |
William Lee Irwin III | dfaa9c9 | 2005-05-16 21:53:58 -0700 | [diff] [blame] | 52 | static char __initdata schedstr[] = "schedule"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | int par; |
| 54 | |
William Lee Irwin III | dfaa9c9 | 2005-05-16 21:53:58 -0700 | [diff] [blame] | 55 | if (!strncmp(str, schedstr, strlen(schedstr))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | prof_on = SCHED_PROFILING; |
William Lee Irwin III | dfaa9c9 | 2005-05-16 21:53:58 -0700 | [diff] [blame] | 57 | if (str[strlen(schedstr)] == ',') |
| 58 | str += strlen(schedstr) + 1; |
| 59 | if (get_option(&str, &par)) |
| 60 | prof_shift = par; |
| 61 | printk(KERN_INFO |
| 62 | "kernel schedule profiling enabled (shift: %ld)\n", |
| 63 | prof_shift); |
| 64 | } else if (get_option(&str, &par)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | prof_shift = par; |
| 66 | prof_on = CPU_PROFILING; |
| 67 | printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n", |
| 68 | prof_shift); |
| 69 | } |
| 70 | return 1; |
| 71 | } |
| 72 | __setup("profile=", profile_setup); |
| 73 | |
| 74 | |
| 75 | void __init profile_init(void) |
| 76 | { |
| 77 | if (!prof_on) |
| 78 | return; |
| 79 | |
| 80 | /* only text is profiled */ |
| 81 | prof_len = (_etext - _stext) >> prof_shift; |
| 82 | prof_buffer = alloc_bootmem(prof_len*sizeof(atomic_t)); |
| 83 | } |
| 84 | |
| 85 | /* Profile event notifications */ |
| 86 | |
| 87 | #ifdef CONFIG_PROFILING |
| 88 | |
| 89 | static DECLARE_RWSEM(profile_rwsem); |
| 90 | static DEFINE_RWLOCK(handoff_lock); |
| 91 | static struct notifier_block * task_exit_notifier; |
| 92 | static struct notifier_block * task_free_notifier; |
| 93 | static struct notifier_block * munmap_notifier; |
| 94 | |
| 95 | void profile_task_exit(struct task_struct * task) |
| 96 | { |
| 97 | down_read(&profile_rwsem); |
| 98 | notifier_call_chain(&task_exit_notifier, 0, task); |
| 99 | up_read(&profile_rwsem); |
| 100 | } |
| 101 | |
| 102 | int profile_handoff_task(struct task_struct * task) |
| 103 | { |
| 104 | int ret; |
| 105 | read_lock(&handoff_lock); |
| 106 | ret = notifier_call_chain(&task_free_notifier, 0, task); |
| 107 | read_unlock(&handoff_lock); |
| 108 | return (ret == NOTIFY_OK) ? 1 : 0; |
| 109 | } |
| 110 | |
| 111 | void profile_munmap(unsigned long addr) |
| 112 | { |
| 113 | down_read(&profile_rwsem); |
| 114 | notifier_call_chain(&munmap_notifier, 0, (void *)addr); |
| 115 | up_read(&profile_rwsem); |
| 116 | } |
| 117 | |
| 118 | int task_handoff_register(struct notifier_block * n) |
| 119 | { |
| 120 | int err = -EINVAL; |
| 121 | |
| 122 | write_lock(&handoff_lock); |
| 123 | err = notifier_chain_register(&task_free_notifier, n); |
| 124 | write_unlock(&handoff_lock); |
| 125 | return err; |
| 126 | } |
| 127 | |
| 128 | int task_handoff_unregister(struct notifier_block * n) |
| 129 | { |
| 130 | int err = -EINVAL; |
| 131 | |
| 132 | write_lock(&handoff_lock); |
| 133 | err = notifier_chain_unregister(&task_free_notifier, n); |
| 134 | write_unlock(&handoff_lock); |
| 135 | return err; |
| 136 | } |
| 137 | |
| 138 | int profile_event_register(enum profile_type type, struct notifier_block * n) |
| 139 | { |
| 140 | int err = -EINVAL; |
| 141 | |
| 142 | down_write(&profile_rwsem); |
| 143 | |
| 144 | switch (type) { |
| 145 | case PROFILE_TASK_EXIT: |
| 146 | err = notifier_chain_register(&task_exit_notifier, n); |
| 147 | break; |
| 148 | case PROFILE_MUNMAP: |
| 149 | err = notifier_chain_register(&munmap_notifier, n); |
| 150 | break; |
| 151 | } |
| 152 | |
| 153 | up_write(&profile_rwsem); |
| 154 | |
| 155 | return err; |
| 156 | } |
| 157 | |
| 158 | |
| 159 | int profile_event_unregister(enum profile_type type, struct notifier_block * n) |
| 160 | { |
| 161 | int err = -EINVAL; |
| 162 | |
| 163 | down_write(&profile_rwsem); |
| 164 | |
| 165 | switch (type) { |
| 166 | case PROFILE_TASK_EXIT: |
| 167 | err = notifier_chain_unregister(&task_exit_notifier, n); |
| 168 | break; |
| 169 | case PROFILE_MUNMAP: |
| 170 | err = notifier_chain_unregister(&munmap_notifier, n); |
| 171 | break; |
| 172 | } |
| 173 | |
| 174 | up_write(&profile_rwsem); |
| 175 | return err; |
| 176 | } |
| 177 | |
| 178 | int register_timer_hook(int (*hook)(struct pt_regs *)) |
| 179 | { |
| 180 | if (timer_hook) |
| 181 | return -EBUSY; |
| 182 | timer_hook = hook; |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | void unregister_timer_hook(int (*hook)(struct pt_regs *)) |
| 187 | { |
| 188 | WARN_ON(hook != timer_hook); |
| 189 | timer_hook = NULL; |
| 190 | /* make sure all CPUs see the NULL hook */ |
Paul E. McKenney | fbd568a3e | 2005-05-01 08:59:04 -0700 | [diff] [blame] | 191 | synchronize_sched(); /* Allow ongoing interrupts to complete. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | } |
| 193 | |
| 194 | EXPORT_SYMBOL_GPL(register_timer_hook); |
| 195 | EXPORT_SYMBOL_GPL(unregister_timer_hook); |
| 196 | EXPORT_SYMBOL_GPL(task_handoff_register); |
| 197 | EXPORT_SYMBOL_GPL(task_handoff_unregister); |
| 198 | |
| 199 | #endif /* CONFIG_PROFILING */ |
| 200 | |
| 201 | EXPORT_SYMBOL_GPL(profile_event_register); |
| 202 | EXPORT_SYMBOL_GPL(profile_event_unregister); |
| 203 | |
| 204 | #ifdef CONFIG_SMP |
| 205 | /* |
| 206 | * Each cpu has a pair of open-addressed hashtables for pending |
| 207 | * profile hits. read_profile() IPI's all cpus to request them |
| 208 | * to flip buffers and flushes their contents to prof_buffer itself. |
| 209 | * Flip requests are serialized by the profile_flip_mutex. The sole |
| 210 | * use of having a second hashtable is for avoiding cacheline |
| 211 | * contention that would otherwise happen during flushes of pending |
| 212 | * profile hits required for the accuracy of reported profile hits |
| 213 | * and so resurrect the interrupt livelock issue. |
| 214 | * |
| 215 | * The open-addressed hashtables are indexed by profile buffer slot |
| 216 | * and hold the number of pending hits to that profile buffer slot on |
| 217 | * a cpu in an entry. When the hashtable overflows, all pending hits |
| 218 | * are accounted to their corresponding profile buffer slots with |
| 219 | * atomic_add() and the hashtable emptied. As numerous pending hits |
| 220 | * may be accounted to a profile buffer slot in a hashtable entry, |
| 221 | * this amortizes a number of atomic profile buffer increments likely |
| 222 | * to be far larger than the number of entries in the hashtable, |
| 223 | * particularly given that the number of distinct profile buffer |
| 224 | * positions to which hits are accounted during short intervals (e.g. |
| 225 | * several seconds) is usually very small. Exclusion from buffer |
| 226 | * flipping is provided by interrupt disablement (note that for |
| 227 | * SCHED_PROFILING profile_hit() may be called from process context). |
| 228 | * The hash function is meant to be lightweight as opposed to strong, |
| 229 | * and was vaguely inspired by ppc64 firmware-supported inverted |
| 230 | * pagetable hash functions, but uses a full hashtable full of finite |
| 231 | * collision chains, not just pairs of them. |
| 232 | * |
| 233 | * -- wli |
| 234 | */ |
| 235 | static void __profile_flip_buffers(void *unused) |
| 236 | { |
| 237 | int cpu = smp_processor_id(); |
| 238 | |
| 239 | per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); |
| 240 | } |
| 241 | |
| 242 | static void profile_flip_buffers(void) |
| 243 | { |
| 244 | int i, j, cpu; |
| 245 | |
| 246 | down(&profile_flip_mutex); |
| 247 | j = per_cpu(cpu_profile_flip, get_cpu()); |
| 248 | put_cpu(); |
| 249 | on_each_cpu(__profile_flip_buffers, NULL, 0, 1); |
| 250 | for_each_online_cpu(cpu) { |
| 251 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; |
| 252 | for (i = 0; i < NR_PROFILE_HIT; ++i) { |
| 253 | if (!hits[i].hits) { |
| 254 | if (hits[i].pc) |
| 255 | hits[i].pc = 0; |
| 256 | continue; |
| 257 | } |
| 258 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); |
| 259 | hits[i].hits = hits[i].pc = 0; |
| 260 | } |
| 261 | } |
| 262 | up(&profile_flip_mutex); |
| 263 | } |
| 264 | |
| 265 | static void profile_discard_flip_buffers(void) |
| 266 | { |
| 267 | int i, cpu; |
| 268 | |
| 269 | down(&profile_flip_mutex); |
| 270 | i = per_cpu(cpu_profile_flip, get_cpu()); |
| 271 | put_cpu(); |
| 272 | on_each_cpu(__profile_flip_buffers, NULL, 0, 1); |
| 273 | for_each_online_cpu(cpu) { |
| 274 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; |
| 275 | memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); |
| 276 | } |
| 277 | up(&profile_flip_mutex); |
| 278 | } |
| 279 | |
| 280 | void profile_hit(int type, void *__pc) |
| 281 | { |
| 282 | unsigned long primary, secondary, flags, pc = (unsigned long)__pc; |
| 283 | int i, j, cpu; |
| 284 | struct profile_hit *hits; |
| 285 | |
| 286 | if (prof_on != type || !prof_buffer) |
| 287 | return; |
| 288 | pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); |
| 289 | i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; |
| 290 | secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; |
| 291 | cpu = get_cpu(); |
| 292 | hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; |
| 293 | if (!hits) { |
| 294 | put_cpu(); |
| 295 | return; |
| 296 | } |
| 297 | local_irq_save(flags); |
| 298 | do { |
| 299 | for (j = 0; j < PROFILE_GRPSZ; ++j) { |
| 300 | if (hits[i + j].pc == pc) { |
| 301 | hits[i + j].hits++; |
| 302 | goto out; |
| 303 | } else if (!hits[i + j].hits) { |
| 304 | hits[i + j].pc = pc; |
| 305 | hits[i + j].hits = 1; |
| 306 | goto out; |
| 307 | } |
| 308 | } |
| 309 | i = (i + secondary) & (NR_PROFILE_HIT - 1); |
| 310 | } while (i != primary); |
| 311 | atomic_inc(&prof_buffer[pc]); |
| 312 | for (i = 0; i < NR_PROFILE_HIT; ++i) { |
| 313 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); |
| 314 | hits[i].pc = hits[i].hits = 0; |
| 315 | } |
| 316 | out: |
| 317 | local_irq_restore(flags); |
| 318 | put_cpu(); |
| 319 | } |
| 320 | |
| 321 | #ifdef CONFIG_HOTPLUG_CPU |
| 322 | static int __devinit profile_cpu_callback(struct notifier_block *info, |
| 323 | unsigned long action, void *__cpu) |
| 324 | { |
| 325 | int node, cpu = (unsigned long)__cpu; |
| 326 | struct page *page; |
| 327 | |
| 328 | switch (action) { |
| 329 | case CPU_UP_PREPARE: |
| 330 | node = cpu_to_node(cpu); |
| 331 | per_cpu(cpu_profile_flip, cpu) = 0; |
| 332 | if (!per_cpu(cpu_profile_hits, cpu)[1]) { |
| 333 | page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); |
| 334 | if (!page) |
| 335 | return NOTIFY_BAD; |
| 336 | per_cpu(cpu_profile_hits, cpu)[1] = page_address(page); |
| 337 | } |
| 338 | if (!per_cpu(cpu_profile_hits, cpu)[0]) { |
| 339 | page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); |
| 340 | if (!page) |
| 341 | goto out_free; |
| 342 | per_cpu(cpu_profile_hits, cpu)[0] = page_address(page); |
| 343 | } |
| 344 | break; |
| 345 | out_free: |
| 346 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); |
| 347 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; |
| 348 | __free_page(page); |
| 349 | return NOTIFY_BAD; |
| 350 | case CPU_ONLINE: |
| 351 | cpu_set(cpu, prof_cpu_mask); |
| 352 | break; |
| 353 | case CPU_UP_CANCELED: |
| 354 | case CPU_DEAD: |
| 355 | cpu_clear(cpu, prof_cpu_mask); |
| 356 | if (per_cpu(cpu_profile_hits, cpu)[0]) { |
| 357 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); |
| 358 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; |
| 359 | __free_page(page); |
| 360 | } |
| 361 | if (per_cpu(cpu_profile_hits, cpu)[1]) { |
| 362 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); |
| 363 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; |
| 364 | __free_page(page); |
| 365 | } |
| 366 | break; |
| 367 | } |
| 368 | return NOTIFY_OK; |
| 369 | } |
| 370 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 371 | #else /* !CONFIG_SMP */ |
| 372 | #define profile_flip_buffers() do { } while (0) |
| 373 | #define profile_discard_flip_buffers() do { } while (0) |
| 374 | |
| 375 | void profile_hit(int type, void *__pc) |
| 376 | { |
| 377 | unsigned long pc; |
| 378 | |
| 379 | if (prof_on != type || !prof_buffer) |
| 380 | return; |
| 381 | pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; |
| 382 | atomic_inc(&prof_buffer[min(pc, prof_len - 1)]); |
| 383 | } |
| 384 | #endif /* !CONFIG_SMP */ |
| 385 | |
| 386 | void profile_tick(int type, struct pt_regs *regs) |
| 387 | { |
| 388 | if (type == CPU_PROFILING && timer_hook) |
| 389 | timer_hook(regs); |
| 390 | if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask)) |
| 391 | profile_hit(type, (void *)profile_pc(regs)); |
| 392 | } |
| 393 | |
| 394 | #ifdef CONFIG_PROC_FS |
| 395 | #include <linux/proc_fs.h> |
| 396 | #include <asm/uaccess.h> |
| 397 | #include <asm/ptrace.h> |
| 398 | |
| 399 | static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, |
| 400 | int count, int *eof, void *data) |
| 401 | { |
| 402 | int len = cpumask_scnprintf(page, count, *(cpumask_t *)data); |
| 403 | if (count - len < 2) |
| 404 | return -EINVAL; |
| 405 | len += sprintf(page + len, "\n"); |
| 406 | return len; |
| 407 | } |
| 408 | |
| 409 | static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer, |
| 410 | unsigned long count, void *data) |
| 411 | { |
| 412 | cpumask_t *mask = (cpumask_t *)data; |
| 413 | unsigned long full_count = count, err; |
| 414 | cpumask_t new_value; |
| 415 | |
| 416 | err = cpumask_parse(buffer, count, new_value); |
| 417 | if (err) |
| 418 | return err; |
| 419 | |
| 420 | *mask = new_value; |
| 421 | return full_count; |
| 422 | } |
| 423 | |
| 424 | void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) |
| 425 | { |
| 426 | struct proc_dir_entry *entry; |
| 427 | |
| 428 | /* create /proc/irq/prof_cpu_mask */ |
| 429 | if (!(entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir))) |
| 430 | return; |
| 431 | entry->nlink = 1; |
| 432 | entry->data = (void *)&prof_cpu_mask; |
| 433 | entry->read_proc = prof_cpu_mask_read_proc; |
| 434 | entry->write_proc = prof_cpu_mask_write_proc; |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * This function accesses profiling information. The returned data is |
| 439 | * binary: the sampling step and the actual contents of the profile |
| 440 | * buffer. Use of the program readprofile is recommended in order to |
| 441 | * get meaningful info out of these data. |
| 442 | */ |
| 443 | static ssize_t |
| 444 | read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 445 | { |
| 446 | unsigned long p = *ppos; |
| 447 | ssize_t read; |
| 448 | char * pnt; |
| 449 | unsigned int sample_step = 1 << prof_shift; |
| 450 | |
| 451 | profile_flip_buffers(); |
| 452 | if (p >= (prof_len+1)*sizeof(unsigned int)) |
| 453 | return 0; |
| 454 | if (count > (prof_len+1)*sizeof(unsigned int) - p) |
| 455 | count = (prof_len+1)*sizeof(unsigned int) - p; |
| 456 | read = 0; |
| 457 | |
| 458 | while (p < sizeof(unsigned int) && count > 0) { |
| 459 | put_user(*((char *)(&sample_step)+p),buf); |
| 460 | buf++; p++; count--; read++; |
| 461 | } |
| 462 | pnt = (char *)prof_buffer + p - sizeof(atomic_t); |
| 463 | if (copy_to_user(buf,(void *)pnt,count)) |
| 464 | return -EFAULT; |
| 465 | read += count; |
| 466 | *ppos += read; |
| 467 | return read; |
| 468 | } |
| 469 | |
| 470 | /* |
| 471 | * Writing to /proc/profile resets the counters |
| 472 | * |
| 473 | * Writing a 'profiling multiplier' value into it also re-sets the profiling |
| 474 | * interrupt frequency, on architectures that support this. |
| 475 | */ |
| 476 | static ssize_t write_profile(struct file *file, const char __user *buf, |
| 477 | size_t count, loff_t *ppos) |
| 478 | { |
| 479 | #ifdef CONFIG_SMP |
| 480 | extern int setup_profiling_timer (unsigned int multiplier); |
| 481 | |
| 482 | if (count == sizeof(int)) { |
| 483 | unsigned int multiplier; |
| 484 | |
| 485 | if (copy_from_user(&multiplier, buf, sizeof(int))) |
| 486 | return -EFAULT; |
| 487 | |
| 488 | if (setup_profiling_timer(multiplier)) |
| 489 | return -EINVAL; |
| 490 | } |
| 491 | #endif |
| 492 | profile_discard_flip_buffers(); |
| 493 | memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); |
| 494 | return count; |
| 495 | } |
| 496 | |
| 497 | static struct file_operations proc_profile_operations = { |
| 498 | .read = read_profile, |
| 499 | .write = write_profile, |
| 500 | }; |
| 501 | |
| 502 | #ifdef CONFIG_SMP |
| 503 | static void __init profile_nop(void *unused) |
| 504 | { |
| 505 | } |
| 506 | |
| 507 | static int __init create_hash_tables(void) |
| 508 | { |
| 509 | int cpu; |
| 510 | |
| 511 | for_each_online_cpu(cpu) { |
| 512 | int node = cpu_to_node(cpu); |
| 513 | struct page *page; |
| 514 | |
| 515 | page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); |
| 516 | if (!page) |
| 517 | goto out_cleanup; |
| 518 | per_cpu(cpu_profile_hits, cpu)[1] |
| 519 | = (struct profile_hit *)page_address(page); |
| 520 | page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); |
| 521 | if (!page) |
| 522 | goto out_cleanup; |
| 523 | per_cpu(cpu_profile_hits, cpu)[0] |
| 524 | = (struct profile_hit *)page_address(page); |
| 525 | } |
| 526 | return 0; |
| 527 | out_cleanup: |
| 528 | prof_on = 0; |
akpm@osdl.org | d59dd46 | 2005-05-01 08:58:47 -0700 | [diff] [blame] | 529 | smp_mb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | on_each_cpu(profile_nop, NULL, 0, 1); |
| 531 | for_each_online_cpu(cpu) { |
| 532 | struct page *page; |
| 533 | |
| 534 | if (per_cpu(cpu_profile_hits, cpu)[0]) { |
| 535 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); |
| 536 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; |
| 537 | __free_page(page); |
| 538 | } |
| 539 | if (per_cpu(cpu_profile_hits, cpu)[1]) { |
| 540 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); |
| 541 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; |
| 542 | __free_page(page); |
| 543 | } |
| 544 | } |
| 545 | return -1; |
| 546 | } |
| 547 | #else |
| 548 | #define create_hash_tables() ({ 0; }) |
| 549 | #endif |
| 550 | |
| 551 | static int __init create_proc_profile(void) |
| 552 | { |
| 553 | struct proc_dir_entry *entry; |
| 554 | |
| 555 | if (!prof_on) |
| 556 | return 0; |
| 557 | if (create_hash_tables()) |
| 558 | return -1; |
| 559 | if (!(entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL))) |
| 560 | return 0; |
| 561 | entry->proc_fops = &proc_profile_operations; |
| 562 | entry->size = (1+prof_len) * sizeof(atomic_t); |
| 563 | hotcpu_notifier(profile_cpu_callback, 0); |
| 564 | return 0; |
| 565 | } |
| 566 | module_init(create_proc_profile); |
| 567 | #endif /* CONFIG_PROC_FS */ |