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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 | * Nadia Yvette Chambers, Oracle, July 2004 | |
12 | * Amortized hit count accounting via per-cpu open-addressed hashtables | |
13 | * to resolve timer interrupt livelocks, Nadia Yvette Chambers, | |
14 | * Oracle, 2004 | |
15 | */ | |
16 | ||
17 | #include <linux/export.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/highmem.h> | |
25 | #include <linux/mutex.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/vmalloc.h> | |
28 | #include <asm/sections.h> | |
29 | #include <asm/irq_regs.h> | |
30 | #include <asm/ptrace.h> | |
31 | ||
32 | struct profile_hit { | |
33 | u32 pc, hits; | |
34 | }; | |
35 | #define PROFILE_GRPSHIFT 3 | |
36 | #define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) | |
37 | #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) | |
38 | #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) | |
39 | ||
40 | static atomic_t *prof_buffer; | |
41 | static unsigned long prof_len, prof_shift; | |
42 | ||
43 | int prof_on __read_mostly; | |
44 | EXPORT_SYMBOL_GPL(prof_on); | |
45 | ||
46 | static cpumask_var_t prof_cpu_mask; | |
47 | #ifdef CONFIG_SMP | |
48 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); | |
49 | static DEFINE_PER_CPU(int, cpu_profile_flip); | |
50 | static DEFINE_MUTEX(profile_flip_mutex); | |
51 | #endif /* CONFIG_SMP */ | |
52 | ||
53 | int profile_setup(char *str) | |
54 | { | |
55 | static char schedstr[] = "schedule"; | |
56 | static char sleepstr[] = "sleep"; | |
57 | static char kvmstr[] = "kvm"; | |
58 | int par; | |
59 | ||
60 | if (!strncmp(str, sleepstr, strlen(sleepstr))) { | |
61 | #ifdef CONFIG_SCHEDSTATS | |
62 | prof_on = SLEEP_PROFILING; | |
63 | if (str[strlen(sleepstr)] == ',') | |
64 | str += strlen(sleepstr) + 1; | |
65 | if (get_option(&str, &par)) | |
66 | prof_shift = par; | |
67 | printk(KERN_INFO | |
68 | "kernel sleep profiling enabled (shift: %ld)\n", | |
69 | prof_shift); | |
70 | #else | |
71 | printk(KERN_WARNING | |
72 | "kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); | |
73 | #endif /* CONFIG_SCHEDSTATS */ | |
74 | } else if (!strncmp(str, schedstr, strlen(schedstr))) { | |
75 | prof_on = SCHED_PROFILING; | |
76 | if (str[strlen(schedstr)] == ',') | |
77 | str += strlen(schedstr) + 1; | |
78 | if (get_option(&str, &par)) | |
79 | prof_shift = par; | |
80 | printk(KERN_INFO | |
81 | "kernel schedule profiling enabled (shift: %ld)\n", | |
82 | prof_shift); | |
83 | } else if (!strncmp(str, kvmstr, strlen(kvmstr))) { | |
84 | prof_on = KVM_PROFILING; | |
85 | if (str[strlen(kvmstr)] == ',') | |
86 | str += strlen(kvmstr) + 1; | |
87 | if (get_option(&str, &par)) | |
88 | prof_shift = par; | |
89 | printk(KERN_INFO | |
90 | "kernel KVM profiling enabled (shift: %ld)\n", | |
91 | prof_shift); | |
92 | } else if (get_option(&str, &par)) { | |
93 | prof_shift = par; | |
94 | prof_on = CPU_PROFILING; | |
95 | printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n", | |
96 | prof_shift); | |
97 | } | |
98 | return 1; | |
99 | } | |
100 | __setup("profile=", profile_setup); | |
101 | ||
102 | ||
103 | int __ref profile_init(void) | |
104 | { | |
105 | int buffer_bytes; | |
106 | if (!prof_on) | |
107 | return 0; | |
108 | ||
109 | /* only text is profiled */ | |
110 | prof_len = (_etext - _stext) >> prof_shift; | |
111 | buffer_bytes = prof_len*sizeof(atomic_t); | |
112 | ||
113 | if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) | |
114 | return -ENOMEM; | |
115 | ||
116 | cpumask_copy(prof_cpu_mask, cpu_possible_mask); | |
117 | ||
118 | prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN); | |
119 | if (prof_buffer) | |
120 | return 0; | |
121 | ||
122 | prof_buffer = alloc_pages_exact(buffer_bytes, | |
123 | GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN); | |
124 | if (prof_buffer) | |
125 | return 0; | |
126 | ||
127 | prof_buffer = vzalloc(buffer_bytes); | |
128 | if (prof_buffer) | |
129 | return 0; | |
130 | ||
131 | free_cpumask_var(prof_cpu_mask); | |
132 | return -ENOMEM; | |
133 | } | |
134 | ||
135 | /* Profile event notifications */ | |
136 | ||
137 | static BLOCKING_NOTIFIER_HEAD(task_exit_notifier); | |
138 | static ATOMIC_NOTIFIER_HEAD(task_free_notifier); | |
139 | static BLOCKING_NOTIFIER_HEAD(munmap_notifier); | |
140 | ||
141 | void profile_task_exit(struct task_struct *task) | |
142 | { | |
143 | blocking_notifier_call_chain(&task_exit_notifier, 0, task); | |
144 | } | |
145 | ||
146 | int profile_handoff_task(struct task_struct *task) | |
147 | { | |
148 | int ret; | |
149 | ret = atomic_notifier_call_chain(&task_free_notifier, 0, task); | |
150 | return (ret == NOTIFY_OK) ? 1 : 0; | |
151 | } | |
152 | ||
153 | void profile_munmap(unsigned long addr) | |
154 | { | |
155 | blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr); | |
156 | } | |
157 | ||
158 | int task_handoff_register(struct notifier_block *n) | |
159 | { | |
160 | return atomic_notifier_chain_register(&task_free_notifier, n); | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(task_handoff_register); | |
163 | ||
164 | int task_handoff_unregister(struct notifier_block *n) | |
165 | { | |
166 | return atomic_notifier_chain_unregister(&task_free_notifier, n); | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(task_handoff_unregister); | |
169 | ||
170 | int profile_event_register(enum profile_type type, struct notifier_block *n) | |
171 | { | |
172 | int err = -EINVAL; | |
173 | ||
174 | switch (type) { | |
175 | case PROFILE_TASK_EXIT: | |
176 | err = blocking_notifier_chain_register( | |
177 | &task_exit_notifier, n); | |
178 | break; | |
179 | case PROFILE_MUNMAP: | |
180 | err = blocking_notifier_chain_register( | |
181 | &munmap_notifier, n); | |
182 | break; | |
183 | } | |
184 | ||
185 | return err; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(profile_event_register); | |
188 | ||
189 | int profile_event_unregister(enum profile_type type, struct notifier_block *n) | |
190 | { | |
191 | int err = -EINVAL; | |
192 | ||
193 | switch (type) { | |
194 | case PROFILE_TASK_EXIT: | |
195 | err = blocking_notifier_chain_unregister( | |
196 | &task_exit_notifier, n); | |
197 | break; | |
198 | case PROFILE_MUNMAP: | |
199 | err = blocking_notifier_chain_unregister( | |
200 | &munmap_notifier, n); | |
201 | break; | |
202 | } | |
203 | ||
204 | return err; | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(profile_event_unregister); | |
207 | ||
208 | #ifdef CONFIG_SMP | |
209 | /* | |
210 | * Each cpu has a pair of open-addressed hashtables for pending | |
211 | * profile hits. read_profile() IPI's all cpus to request them | |
212 | * to flip buffers and flushes their contents to prof_buffer itself. | |
213 | * Flip requests are serialized by the profile_flip_mutex. The sole | |
214 | * use of having a second hashtable is for avoiding cacheline | |
215 | * contention that would otherwise happen during flushes of pending | |
216 | * profile hits required for the accuracy of reported profile hits | |
217 | * and so resurrect the interrupt livelock issue. | |
218 | * | |
219 | * The open-addressed hashtables are indexed by profile buffer slot | |
220 | * and hold the number of pending hits to that profile buffer slot on | |
221 | * a cpu in an entry. When the hashtable overflows, all pending hits | |
222 | * are accounted to their corresponding profile buffer slots with | |
223 | * atomic_add() and the hashtable emptied. As numerous pending hits | |
224 | * may be accounted to a profile buffer slot in a hashtable entry, | |
225 | * this amortizes a number of atomic profile buffer increments likely | |
226 | * to be far larger than the number of entries in the hashtable, | |
227 | * particularly given that the number of distinct profile buffer | |
228 | * positions to which hits are accounted during short intervals (e.g. | |
229 | * several seconds) is usually very small. Exclusion from buffer | |
230 | * flipping is provided by interrupt disablement (note that for | |
231 | * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from | |
232 | * process context). | |
233 | * The hash function is meant to be lightweight as opposed to strong, | |
234 | * and was vaguely inspired by ppc64 firmware-supported inverted | |
235 | * pagetable hash functions, but uses a full hashtable full of finite | |
236 | * collision chains, not just pairs of them. | |
237 | * | |
238 | * -- nyc | |
239 | */ | |
240 | static void __profile_flip_buffers(void *unused) | |
241 | { | |
242 | int cpu = smp_processor_id(); | |
243 | ||
244 | per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); | |
245 | } | |
246 | ||
247 | static void profile_flip_buffers(void) | |
248 | { | |
249 | int i, j, cpu; | |
250 | ||
251 | mutex_lock(&profile_flip_mutex); | |
252 | j = per_cpu(cpu_profile_flip, get_cpu()); | |
253 | put_cpu(); | |
254 | on_each_cpu(__profile_flip_buffers, NULL, 1); | |
255 | for_each_online_cpu(cpu) { | |
256 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; | |
257 | for (i = 0; i < NR_PROFILE_HIT; ++i) { | |
258 | if (!hits[i].hits) { | |
259 | if (hits[i].pc) | |
260 | hits[i].pc = 0; | |
261 | continue; | |
262 | } | |
263 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
264 | hits[i].hits = hits[i].pc = 0; | |
265 | } | |
266 | } | |
267 | mutex_unlock(&profile_flip_mutex); | |
268 | } | |
269 | ||
270 | static void profile_discard_flip_buffers(void) | |
271 | { | |
272 | int i, cpu; | |
273 | ||
274 | mutex_lock(&profile_flip_mutex); | |
275 | i = per_cpu(cpu_profile_flip, get_cpu()); | |
276 | put_cpu(); | |
277 | on_each_cpu(__profile_flip_buffers, NULL, 1); | |
278 | for_each_online_cpu(cpu) { | |
279 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; | |
280 | memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); | |
281 | } | |
282 | mutex_unlock(&profile_flip_mutex); | |
283 | } | |
284 | ||
285 | static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) | |
286 | { | |
287 | unsigned long primary, secondary, flags, pc = (unsigned long)__pc; | |
288 | int i, j, cpu; | |
289 | struct profile_hit *hits; | |
290 | ||
291 | pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); | |
292 | i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
293 | secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
294 | cpu = get_cpu(); | |
295 | hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; | |
296 | if (!hits) { | |
297 | put_cpu(); | |
298 | return; | |
299 | } | |
300 | /* | |
301 | * We buffer the global profiler buffer into a per-CPU | |
302 | * queue and thus reduce the number of global (and possibly | |
303 | * NUMA-alien) accesses. The write-queue is self-coalescing: | |
304 | */ | |
305 | local_irq_save(flags); | |
306 | do { | |
307 | for (j = 0; j < PROFILE_GRPSZ; ++j) { | |
308 | if (hits[i + j].pc == pc) { | |
309 | hits[i + j].hits += nr_hits; | |
310 | goto out; | |
311 | } else if (!hits[i + j].hits) { | |
312 | hits[i + j].pc = pc; | |
313 | hits[i + j].hits = nr_hits; | |
314 | goto out; | |
315 | } | |
316 | } | |
317 | i = (i + secondary) & (NR_PROFILE_HIT - 1); | |
318 | } while (i != primary); | |
319 | ||
320 | /* | |
321 | * Add the current hit(s) and flush the write-queue out | |
322 | * to the global buffer: | |
323 | */ | |
324 | atomic_add(nr_hits, &prof_buffer[pc]); | |
325 | for (i = 0; i < NR_PROFILE_HIT; ++i) { | |
326 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
327 | hits[i].pc = hits[i].hits = 0; | |
328 | } | |
329 | out: | |
330 | local_irq_restore(flags); | |
331 | put_cpu(); | |
332 | } | |
333 | ||
334 | static int profile_cpu_callback(struct notifier_block *info, | |
335 | unsigned long action, void *__cpu) | |
336 | { | |
337 | int node, cpu = (unsigned long)__cpu; | |
338 | struct page *page; | |
339 | ||
340 | switch (action) { | |
341 | case CPU_UP_PREPARE: | |
342 | case CPU_UP_PREPARE_FROZEN: | |
343 | node = cpu_to_mem(cpu); | |
344 | per_cpu(cpu_profile_flip, cpu) = 0; | |
345 | if (!per_cpu(cpu_profile_hits, cpu)[1]) { | |
346 | page = alloc_pages_exact_node(node, | |
347 | GFP_KERNEL | __GFP_ZERO, | |
348 | 0); | |
349 | if (!page) | |
350 | return notifier_from_errno(-ENOMEM); | |
351 | per_cpu(cpu_profile_hits, cpu)[1] = page_address(page); | |
352 | } | |
353 | if (!per_cpu(cpu_profile_hits, cpu)[0]) { | |
354 | page = alloc_pages_exact_node(node, | |
355 | GFP_KERNEL | __GFP_ZERO, | |
356 | 0); | |
357 | if (!page) | |
358 | goto out_free; | |
359 | per_cpu(cpu_profile_hits, cpu)[0] = page_address(page); | |
360 | } | |
361 | break; | |
362 | out_free: | |
363 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
364 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
365 | __free_page(page); | |
366 | return notifier_from_errno(-ENOMEM); | |
367 | case CPU_ONLINE: | |
368 | case CPU_ONLINE_FROZEN: | |
369 | if (prof_cpu_mask != NULL) | |
370 | cpumask_set_cpu(cpu, prof_cpu_mask); | |
371 | break; | |
372 | case CPU_UP_CANCELED: | |
373 | case CPU_UP_CANCELED_FROZEN: | |
374 | case CPU_DEAD: | |
375 | case CPU_DEAD_FROZEN: | |
376 | if (prof_cpu_mask != NULL) | |
377 | cpumask_clear_cpu(cpu, prof_cpu_mask); | |
378 | if (per_cpu(cpu_profile_hits, cpu)[0]) { | |
379 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
380 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
381 | __free_page(page); | |
382 | } | |
383 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
384 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
385 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
386 | __free_page(page); | |
387 | } | |
388 | break; | |
389 | } | |
390 | return NOTIFY_OK; | |
391 | } | |
392 | #else /* !CONFIG_SMP */ | |
393 | #define profile_flip_buffers() do { } while (0) | |
394 | #define profile_discard_flip_buffers() do { } while (0) | |
395 | #define profile_cpu_callback NULL | |
396 | ||
397 | static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) | |
398 | { | |
399 | unsigned long pc; | |
400 | pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; | |
401 | atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); | |
402 | } | |
403 | #endif /* !CONFIG_SMP */ | |
404 | ||
405 | void profile_hits(int type, void *__pc, unsigned int nr_hits) | |
406 | { | |
407 | if (prof_on != type || !prof_buffer) | |
408 | return; | |
409 | do_profile_hits(type, __pc, nr_hits); | |
410 | } | |
411 | EXPORT_SYMBOL_GPL(profile_hits); | |
412 | ||
413 | void profile_tick(int type) | |
414 | { | |
415 | struct pt_regs *regs = get_irq_regs(); | |
416 | ||
417 | if (!user_mode(regs) && prof_cpu_mask != NULL && | |
418 | cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) | |
419 | profile_hit(type, (void *)profile_pc(regs)); | |
420 | } | |
421 | ||
422 | #ifdef CONFIG_PROC_FS | |
423 | #include <linux/proc_fs.h> | |
424 | #include <linux/seq_file.h> | |
425 | #include <asm/uaccess.h> | |
426 | ||
427 | static int prof_cpu_mask_proc_show(struct seq_file *m, void *v) | |
428 | { | |
429 | seq_cpumask(m, prof_cpu_mask); | |
430 | seq_putc(m, '\n'); | |
431 | return 0; | |
432 | } | |
433 | ||
434 | static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file) | |
435 | { | |
436 | return single_open(file, prof_cpu_mask_proc_show, NULL); | |
437 | } | |
438 | ||
439 | static ssize_t prof_cpu_mask_proc_write(struct file *file, | |
440 | const char __user *buffer, size_t count, loff_t *pos) | |
441 | { | |
442 | cpumask_var_t new_value; | |
443 | int err; | |
444 | ||
445 | if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) | |
446 | return -ENOMEM; | |
447 | ||
448 | err = cpumask_parse_user(buffer, count, new_value); | |
449 | if (!err) { | |
450 | cpumask_copy(prof_cpu_mask, new_value); | |
451 | err = count; | |
452 | } | |
453 | free_cpumask_var(new_value); | |
454 | return err; | |
455 | } | |
456 | ||
457 | static const struct file_operations prof_cpu_mask_proc_fops = { | |
458 | .open = prof_cpu_mask_proc_open, | |
459 | .read = seq_read, | |
460 | .llseek = seq_lseek, | |
461 | .release = single_release, | |
462 | .write = prof_cpu_mask_proc_write, | |
463 | }; | |
464 | ||
465 | void create_prof_cpu_mask(void) | |
466 | { | |
467 | /* create /proc/irq/prof_cpu_mask */ | |
468 | proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_fops); | |
469 | } | |
470 | ||
471 | /* | |
472 | * This function accesses profiling information. The returned data is | |
473 | * binary: the sampling step and the actual contents of the profile | |
474 | * buffer. Use of the program readprofile is recommended in order to | |
475 | * get meaningful info out of these data. | |
476 | */ | |
477 | static ssize_t | |
478 | read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
479 | { | |
480 | unsigned long p = *ppos; | |
481 | ssize_t read; | |
482 | char *pnt; | |
483 | unsigned int sample_step = 1 << prof_shift; | |
484 | ||
485 | profile_flip_buffers(); | |
486 | if (p >= (prof_len+1)*sizeof(unsigned int)) | |
487 | return 0; | |
488 | if (count > (prof_len+1)*sizeof(unsigned int) - p) | |
489 | count = (prof_len+1)*sizeof(unsigned int) - p; | |
490 | read = 0; | |
491 | ||
492 | while (p < sizeof(unsigned int) && count > 0) { | |
493 | if (put_user(*((char *)(&sample_step)+p), buf)) | |
494 | return -EFAULT; | |
495 | buf++; p++; count--; read++; | |
496 | } | |
497 | pnt = (char *)prof_buffer + p - sizeof(atomic_t); | |
498 | if (copy_to_user(buf, (void *)pnt, count)) | |
499 | return -EFAULT; | |
500 | read += count; | |
501 | *ppos += read; | |
502 | return read; | |
503 | } | |
504 | ||
505 | /* | |
506 | * Writing to /proc/profile resets the counters | |
507 | * | |
508 | * Writing a 'profiling multiplier' value into it also re-sets the profiling | |
509 | * interrupt frequency, on architectures that support this. | |
510 | */ | |
511 | static ssize_t write_profile(struct file *file, const char __user *buf, | |
512 | size_t count, loff_t *ppos) | |
513 | { | |
514 | #ifdef CONFIG_SMP | |
515 | extern int setup_profiling_timer(unsigned int multiplier); | |
516 | ||
517 | if (count == sizeof(int)) { | |
518 | unsigned int multiplier; | |
519 | ||
520 | if (copy_from_user(&multiplier, buf, sizeof(int))) | |
521 | return -EFAULT; | |
522 | ||
523 | if (setup_profiling_timer(multiplier)) | |
524 | return -EINVAL; | |
525 | } | |
526 | #endif | |
527 | profile_discard_flip_buffers(); | |
528 | memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); | |
529 | return count; | |
530 | } | |
531 | ||
532 | static const struct file_operations proc_profile_operations = { | |
533 | .read = read_profile, | |
534 | .write = write_profile, | |
535 | .llseek = default_llseek, | |
536 | }; | |
537 | ||
538 | #ifdef CONFIG_SMP | |
539 | static void profile_nop(void *unused) | |
540 | { | |
541 | } | |
542 | ||
543 | static int create_hash_tables(void) | |
544 | { | |
545 | int cpu; | |
546 | ||
547 | for_each_online_cpu(cpu) { | |
548 | int node = cpu_to_mem(cpu); | |
549 | struct page *page; | |
550 | ||
551 | page = alloc_pages_exact_node(node, | |
552 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
553 | 0); | |
554 | if (!page) | |
555 | goto out_cleanup; | |
556 | per_cpu(cpu_profile_hits, cpu)[1] | |
557 | = (struct profile_hit *)page_address(page); | |
558 | page = alloc_pages_exact_node(node, | |
559 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
560 | 0); | |
561 | if (!page) | |
562 | goto out_cleanup; | |
563 | per_cpu(cpu_profile_hits, cpu)[0] | |
564 | = (struct profile_hit *)page_address(page); | |
565 | } | |
566 | return 0; | |
567 | out_cleanup: | |
568 | prof_on = 0; | |
569 | smp_mb(); | |
570 | on_each_cpu(profile_nop, NULL, 1); | |
571 | for_each_online_cpu(cpu) { | |
572 | struct page *page; | |
573 | ||
574 | if (per_cpu(cpu_profile_hits, cpu)[0]) { | |
575 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
576 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
577 | __free_page(page); | |
578 | } | |
579 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
580 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
581 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
582 | __free_page(page); | |
583 | } | |
584 | } | |
585 | return -1; | |
586 | } | |
587 | #else | |
588 | #define create_hash_tables() ({ 0; }) | |
589 | #endif | |
590 | ||
591 | int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */ | |
592 | { | |
593 | struct proc_dir_entry *entry; | |
594 | ||
595 | if (!prof_on) | |
596 | return 0; | |
597 | if (create_hash_tables()) | |
598 | return -ENOMEM; | |
599 | entry = proc_create("profile", S_IWUSR | S_IRUGO, | |
600 | NULL, &proc_profile_operations); | |
601 | if (!entry) | |
602 | return 0; | |
603 | proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); | |
604 | hotcpu_notifier(profile_cpu_callback, 0); | |
605 | return 0; | |
606 | } | |
607 | module_init(create_proc_profile); | |
608 | #endif /* CONFIG_PROC_FS */ |