Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
16 | #include <linux/module.h> |
17 | #include <linux/profile.h> | |
18 | #include <linux/bootmem.h> | |
19 | #include <linux/notifier.h> | |
20 | #include <linux/mm.h> | |
21 | #include <linux/cpumask.h> | |
22 | #include <linux/cpu.h> | |
23 | #include <linux/profile.h> | |
24 | #include <linux/highmem.h> | |
97d1f15b | 25 | #include <linux/mutex.h> |
1da177e4 LT |
26 | #include <asm/sections.h> |
27 | #include <asm/semaphore.h> | |
7d12e780 | 28 | #include <asm/irq_regs.h> |
1da177e4 LT |
29 | |
30 | struct profile_hit { | |
31 | u32 pc, hits; | |
32 | }; | |
33 | #define PROFILE_GRPSHIFT 3 | |
34 | #define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) | |
35 | #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) | |
36 | #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) | |
37 | ||
38 | /* Oprofile timer tick hook */ | |
6c036527 | 39 | int (*timer_hook)(struct pt_regs *) __read_mostly; |
1da177e4 LT |
40 | |
41 | static atomic_t *prof_buffer; | |
42 | static unsigned long prof_len, prof_shift; | |
ece8a684 | 43 | int prof_on __read_mostly; |
1da177e4 LT |
44 | static cpumask_t prof_cpu_mask = CPU_MASK_ALL; |
45 | #ifdef CONFIG_SMP | |
46 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); | |
47 | static DEFINE_PER_CPU(int, cpu_profile_flip); | |
97d1f15b | 48 | static DEFINE_MUTEX(profile_flip_mutex); |
1da177e4 LT |
49 | #endif /* CONFIG_SMP */ |
50 | ||
51 | static int __init profile_setup(char * str) | |
52 | { | |
dfaa9c94 | 53 | static char __initdata schedstr[] = "schedule"; |
ece8a684 | 54 | static char __initdata sleepstr[] = "sleep"; |
1da177e4 LT |
55 | int par; |
56 | ||
ece8a684 IM |
57 | if (!strncmp(str, sleepstr, strlen(sleepstr))) { |
58 | prof_on = SLEEP_PROFILING; | |
59 | if (str[strlen(sleepstr)] == ',') | |
60 | str += strlen(sleepstr) + 1; | |
61 | if (get_option(&str, &par)) | |
62 | prof_shift = par; | |
63 | printk(KERN_INFO | |
64 | "kernel sleep profiling enabled (shift: %ld)\n", | |
65 | prof_shift); | |
a75acf85 | 66 | } else if (!strncmp(str, schedstr, strlen(schedstr))) { |
1da177e4 | 67 | prof_on = SCHED_PROFILING; |
dfaa9c94 WLII |
68 | if (str[strlen(schedstr)] == ',') |
69 | str += strlen(schedstr) + 1; | |
70 | if (get_option(&str, &par)) | |
71 | prof_shift = par; | |
72 | printk(KERN_INFO | |
73 | "kernel schedule profiling enabled (shift: %ld)\n", | |
74 | prof_shift); | |
75 | } else if (get_option(&str, &par)) { | |
1da177e4 LT |
76 | prof_shift = par; |
77 | prof_on = CPU_PROFILING; | |
78 | printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n", | |
79 | prof_shift); | |
80 | } | |
81 | return 1; | |
82 | } | |
83 | __setup("profile=", profile_setup); | |
84 | ||
85 | ||
86 | void __init profile_init(void) | |
87 | { | |
88 | if (!prof_on) | |
89 | return; | |
90 | ||
91 | /* only text is profiled */ | |
92 | prof_len = (_etext - _stext) >> prof_shift; | |
93 | prof_buffer = alloc_bootmem(prof_len*sizeof(atomic_t)); | |
94 | } | |
95 | ||
96 | /* Profile event notifications */ | |
97 | ||
98 | #ifdef CONFIG_PROFILING | |
99 | ||
e041c683 AS |
100 | static BLOCKING_NOTIFIER_HEAD(task_exit_notifier); |
101 | static ATOMIC_NOTIFIER_HEAD(task_free_notifier); | |
102 | static BLOCKING_NOTIFIER_HEAD(munmap_notifier); | |
1da177e4 LT |
103 | |
104 | void profile_task_exit(struct task_struct * task) | |
105 | { | |
e041c683 | 106 | blocking_notifier_call_chain(&task_exit_notifier, 0, task); |
1da177e4 LT |
107 | } |
108 | ||
109 | int profile_handoff_task(struct task_struct * task) | |
110 | { | |
111 | int ret; | |
e041c683 | 112 | ret = atomic_notifier_call_chain(&task_free_notifier, 0, task); |
1da177e4 LT |
113 | return (ret == NOTIFY_OK) ? 1 : 0; |
114 | } | |
115 | ||
116 | void profile_munmap(unsigned long addr) | |
117 | { | |
e041c683 | 118 | blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr); |
1da177e4 LT |
119 | } |
120 | ||
121 | int task_handoff_register(struct notifier_block * n) | |
122 | { | |
e041c683 | 123 | return atomic_notifier_chain_register(&task_free_notifier, n); |
1da177e4 LT |
124 | } |
125 | ||
126 | int task_handoff_unregister(struct notifier_block * n) | |
127 | { | |
e041c683 | 128 | return atomic_notifier_chain_unregister(&task_free_notifier, n); |
1da177e4 LT |
129 | } |
130 | ||
131 | int profile_event_register(enum profile_type type, struct notifier_block * n) | |
132 | { | |
133 | int err = -EINVAL; | |
134 | ||
1da177e4 LT |
135 | switch (type) { |
136 | case PROFILE_TASK_EXIT: | |
e041c683 AS |
137 | err = blocking_notifier_chain_register( |
138 | &task_exit_notifier, n); | |
1da177e4 LT |
139 | break; |
140 | case PROFILE_MUNMAP: | |
e041c683 AS |
141 | err = blocking_notifier_chain_register( |
142 | &munmap_notifier, n); | |
1da177e4 LT |
143 | break; |
144 | } | |
145 | ||
1da177e4 LT |
146 | return err; |
147 | } | |
148 | ||
149 | ||
150 | int profile_event_unregister(enum profile_type type, struct notifier_block * n) | |
151 | { | |
152 | int err = -EINVAL; | |
153 | ||
1da177e4 LT |
154 | switch (type) { |
155 | case PROFILE_TASK_EXIT: | |
e041c683 AS |
156 | err = blocking_notifier_chain_unregister( |
157 | &task_exit_notifier, n); | |
1da177e4 LT |
158 | break; |
159 | case PROFILE_MUNMAP: | |
e041c683 AS |
160 | err = blocking_notifier_chain_unregister( |
161 | &munmap_notifier, n); | |
1da177e4 LT |
162 | break; |
163 | } | |
164 | ||
1da177e4 LT |
165 | return err; |
166 | } | |
167 | ||
168 | int register_timer_hook(int (*hook)(struct pt_regs *)) | |
169 | { | |
170 | if (timer_hook) | |
171 | return -EBUSY; | |
172 | timer_hook = hook; | |
173 | return 0; | |
174 | } | |
175 | ||
176 | void unregister_timer_hook(int (*hook)(struct pt_regs *)) | |
177 | { | |
178 | WARN_ON(hook != timer_hook); | |
179 | timer_hook = NULL; | |
180 | /* make sure all CPUs see the NULL hook */ | |
fbd568a3 | 181 | synchronize_sched(); /* Allow ongoing interrupts to complete. */ |
1da177e4 LT |
182 | } |
183 | ||
184 | EXPORT_SYMBOL_GPL(register_timer_hook); | |
185 | EXPORT_SYMBOL_GPL(unregister_timer_hook); | |
186 | EXPORT_SYMBOL_GPL(task_handoff_register); | |
187 | EXPORT_SYMBOL_GPL(task_handoff_unregister); | |
188 | ||
189 | #endif /* CONFIG_PROFILING */ | |
190 | ||
191 | EXPORT_SYMBOL_GPL(profile_event_register); | |
192 | EXPORT_SYMBOL_GPL(profile_event_unregister); | |
193 | ||
194 | #ifdef CONFIG_SMP | |
195 | /* | |
196 | * Each cpu has a pair of open-addressed hashtables for pending | |
197 | * profile hits. read_profile() IPI's all cpus to request them | |
198 | * to flip buffers and flushes their contents to prof_buffer itself. | |
199 | * Flip requests are serialized by the profile_flip_mutex. The sole | |
200 | * use of having a second hashtable is for avoiding cacheline | |
201 | * contention that would otherwise happen during flushes of pending | |
202 | * profile hits required for the accuracy of reported profile hits | |
203 | * and so resurrect the interrupt livelock issue. | |
204 | * | |
205 | * The open-addressed hashtables are indexed by profile buffer slot | |
206 | * and hold the number of pending hits to that profile buffer slot on | |
207 | * a cpu in an entry. When the hashtable overflows, all pending hits | |
208 | * are accounted to their corresponding profile buffer slots with | |
209 | * atomic_add() and the hashtable emptied. As numerous pending hits | |
210 | * may be accounted to a profile buffer slot in a hashtable entry, | |
211 | * this amortizes a number of atomic profile buffer increments likely | |
212 | * to be far larger than the number of entries in the hashtable, | |
213 | * particularly given that the number of distinct profile buffer | |
214 | * positions to which hits are accounted during short intervals (e.g. | |
215 | * several seconds) is usually very small. Exclusion from buffer | |
216 | * flipping is provided by interrupt disablement (note that for | |
ece8a684 IM |
217 | * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from |
218 | * process context). | |
1da177e4 LT |
219 | * The hash function is meant to be lightweight as opposed to strong, |
220 | * and was vaguely inspired by ppc64 firmware-supported inverted | |
221 | * pagetable hash functions, but uses a full hashtable full of finite | |
222 | * collision chains, not just pairs of them. | |
223 | * | |
224 | * -- wli | |
225 | */ | |
226 | static void __profile_flip_buffers(void *unused) | |
227 | { | |
228 | int cpu = smp_processor_id(); | |
229 | ||
230 | per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); | |
231 | } | |
232 | ||
233 | static void profile_flip_buffers(void) | |
234 | { | |
235 | int i, j, cpu; | |
236 | ||
97d1f15b | 237 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
238 | j = per_cpu(cpu_profile_flip, get_cpu()); |
239 | put_cpu(); | |
240 | on_each_cpu(__profile_flip_buffers, NULL, 0, 1); | |
241 | for_each_online_cpu(cpu) { | |
242 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; | |
243 | for (i = 0; i < NR_PROFILE_HIT; ++i) { | |
244 | if (!hits[i].hits) { | |
245 | if (hits[i].pc) | |
246 | hits[i].pc = 0; | |
247 | continue; | |
248 | } | |
249 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
250 | hits[i].hits = hits[i].pc = 0; | |
251 | } | |
252 | } | |
97d1f15b | 253 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
254 | } |
255 | ||
256 | static void profile_discard_flip_buffers(void) | |
257 | { | |
258 | int i, cpu; | |
259 | ||
97d1f15b | 260 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
261 | i = per_cpu(cpu_profile_flip, get_cpu()); |
262 | put_cpu(); | |
263 | on_each_cpu(__profile_flip_buffers, NULL, 0, 1); | |
264 | for_each_online_cpu(cpu) { | |
265 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; | |
266 | memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); | |
267 | } | |
97d1f15b | 268 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
269 | } |
270 | ||
ece8a684 | 271 | void profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
272 | { |
273 | unsigned long primary, secondary, flags, pc = (unsigned long)__pc; | |
274 | int i, j, cpu; | |
275 | struct profile_hit *hits; | |
276 | ||
277 | if (prof_on != type || !prof_buffer) | |
278 | return; | |
279 | pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); | |
280 | i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
281 | secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
282 | cpu = get_cpu(); | |
283 | hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; | |
284 | if (!hits) { | |
285 | put_cpu(); | |
286 | return; | |
287 | } | |
ece8a684 IM |
288 | /* |
289 | * We buffer the global profiler buffer into a per-CPU | |
290 | * queue and thus reduce the number of global (and possibly | |
291 | * NUMA-alien) accesses. The write-queue is self-coalescing: | |
292 | */ | |
1da177e4 LT |
293 | local_irq_save(flags); |
294 | do { | |
295 | for (j = 0; j < PROFILE_GRPSZ; ++j) { | |
296 | if (hits[i + j].pc == pc) { | |
ece8a684 | 297 | hits[i + j].hits += nr_hits; |
1da177e4 LT |
298 | goto out; |
299 | } else if (!hits[i + j].hits) { | |
300 | hits[i + j].pc = pc; | |
ece8a684 | 301 | hits[i + j].hits = nr_hits; |
1da177e4 LT |
302 | goto out; |
303 | } | |
304 | } | |
305 | i = (i + secondary) & (NR_PROFILE_HIT - 1); | |
306 | } while (i != primary); | |
ece8a684 IM |
307 | |
308 | /* | |
309 | * Add the current hit(s) and flush the write-queue out | |
310 | * to the global buffer: | |
311 | */ | |
312 | atomic_add(nr_hits, &prof_buffer[pc]); | |
1da177e4 LT |
313 | for (i = 0; i < NR_PROFILE_HIT; ++i) { |
314 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
315 | hits[i].pc = hits[i].hits = 0; | |
316 | } | |
317 | out: | |
318 | local_irq_restore(flags); | |
319 | put_cpu(); | |
320 | } | |
321 | ||
9c7b216d | 322 | static int __devinit profile_cpu_callback(struct notifier_block *info, |
1da177e4 LT |
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]) { | |
fbd98167 CL |
333 | page = alloc_pages_node(node, |
334 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
335 | 0); | |
1da177e4 LT |
336 | if (!page) |
337 | return NOTIFY_BAD; | |
338 | per_cpu(cpu_profile_hits, cpu)[1] = page_address(page); | |
339 | } | |
340 | if (!per_cpu(cpu_profile_hits, cpu)[0]) { | |
fbd98167 CL |
341 | page = alloc_pages_node(node, |
342 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
343 | 0); | |
1da177e4 LT |
344 | if (!page) |
345 | goto out_free; | |
346 | per_cpu(cpu_profile_hits, cpu)[0] = page_address(page); | |
347 | } | |
348 | break; | |
349 | out_free: | |
350 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
351 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
352 | __free_page(page); | |
353 | return NOTIFY_BAD; | |
354 | case CPU_ONLINE: | |
355 | cpu_set(cpu, prof_cpu_mask); | |
356 | break; | |
357 | case CPU_UP_CANCELED: | |
358 | case CPU_DEAD: | |
359 | cpu_clear(cpu, prof_cpu_mask); | |
360 | if (per_cpu(cpu_profile_hits, cpu)[0]) { | |
361 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
362 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
363 | __free_page(page); | |
364 | } | |
365 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
366 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
367 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
368 | __free_page(page); | |
369 | } | |
370 | break; | |
371 | } | |
372 | return NOTIFY_OK; | |
373 | } | |
1da177e4 LT |
374 | #else /* !CONFIG_SMP */ |
375 | #define profile_flip_buffers() do { } while (0) | |
376 | #define profile_discard_flip_buffers() do { } while (0) | |
02316067 | 377 | #define profile_cpu_callback NULL |
1da177e4 | 378 | |
ece8a684 | 379 | void profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
380 | { |
381 | unsigned long pc; | |
382 | ||
383 | if (prof_on != type || !prof_buffer) | |
384 | return; | |
385 | pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; | |
ece8a684 | 386 | atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); |
1da177e4 LT |
387 | } |
388 | #endif /* !CONFIG_SMP */ | |
389 | ||
7d12e780 | 390 | void profile_tick(int type) |
1da177e4 | 391 | { |
7d12e780 DH |
392 | struct pt_regs *regs = get_irq_regs(); |
393 | ||
1da177e4 LT |
394 | if (type == CPU_PROFILING && timer_hook) |
395 | timer_hook(regs); | |
396 | if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask)) | |
397 | profile_hit(type, (void *)profile_pc(regs)); | |
398 | } | |
399 | ||
400 | #ifdef CONFIG_PROC_FS | |
401 | #include <linux/proc_fs.h> | |
402 | #include <asm/uaccess.h> | |
403 | #include <asm/ptrace.h> | |
404 | ||
405 | static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, | |
406 | int count, int *eof, void *data) | |
407 | { | |
408 | int len = cpumask_scnprintf(page, count, *(cpumask_t *)data); | |
409 | if (count - len < 2) | |
410 | return -EINVAL; | |
411 | len += sprintf(page + len, "\n"); | |
412 | return len; | |
413 | } | |
414 | ||
415 | static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer, | |
416 | unsigned long count, void *data) | |
417 | { | |
418 | cpumask_t *mask = (cpumask_t *)data; | |
419 | unsigned long full_count = count, err; | |
420 | cpumask_t new_value; | |
421 | ||
01a3ee2b | 422 | err = cpumask_parse_user(buffer, count, new_value); |
1da177e4 LT |
423 | if (err) |
424 | return err; | |
425 | ||
426 | *mask = new_value; | |
427 | return full_count; | |
428 | } | |
429 | ||
430 | void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) | |
431 | { | |
432 | struct proc_dir_entry *entry; | |
433 | ||
434 | /* create /proc/irq/prof_cpu_mask */ | |
435 | if (!(entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir))) | |
436 | return; | |
437 | entry->nlink = 1; | |
438 | entry->data = (void *)&prof_cpu_mask; | |
439 | entry->read_proc = prof_cpu_mask_read_proc; | |
440 | entry->write_proc = prof_cpu_mask_write_proc; | |
441 | } | |
442 | ||
443 | /* | |
444 | * This function accesses profiling information. The returned data is | |
445 | * binary: the sampling step and the actual contents of the profile | |
446 | * buffer. Use of the program readprofile is recommended in order to | |
447 | * get meaningful info out of these data. | |
448 | */ | |
449 | static ssize_t | |
450 | read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
451 | { | |
452 | unsigned long p = *ppos; | |
453 | ssize_t read; | |
454 | char * pnt; | |
455 | unsigned int sample_step = 1 << prof_shift; | |
456 | ||
457 | profile_flip_buffers(); | |
458 | if (p >= (prof_len+1)*sizeof(unsigned int)) | |
459 | return 0; | |
460 | if (count > (prof_len+1)*sizeof(unsigned int) - p) | |
461 | count = (prof_len+1)*sizeof(unsigned int) - p; | |
462 | read = 0; | |
463 | ||
464 | while (p < sizeof(unsigned int) && count > 0) { | |
064b022c HC |
465 | if (put_user(*((char *)(&sample_step)+p),buf)) |
466 | return -EFAULT; | |
1da177e4 LT |
467 | buf++; p++; count--; read++; |
468 | } | |
469 | pnt = (char *)prof_buffer + p - sizeof(atomic_t); | |
470 | if (copy_to_user(buf,(void *)pnt,count)) | |
471 | return -EFAULT; | |
472 | read += count; | |
473 | *ppos += read; | |
474 | return read; | |
475 | } | |
476 | ||
477 | /* | |
478 | * Writing to /proc/profile resets the counters | |
479 | * | |
480 | * Writing a 'profiling multiplier' value into it also re-sets the profiling | |
481 | * interrupt frequency, on architectures that support this. | |
482 | */ | |
483 | static ssize_t write_profile(struct file *file, const char __user *buf, | |
484 | size_t count, loff_t *ppos) | |
485 | { | |
486 | #ifdef CONFIG_SMP | |
487 | extern int setup_profiling_timer (unsigned int multiplier); | |
488 | ||
489 | if (count == sizeof(int)) { | |
490 | unsigned int multiplier; | |
491 | ||
492 | if (copy_from_user(&multiplier, buf, sizeof(int))) | |
493 | return -EFAULT; | |
494 | ||
495 | if (setup_profiling_timer(multiplier)) | |
496 | return -EINVAL; | |
497 | } | |
498 | #endif | |
499 | profile_discard_flip_buffers(); | |
500 | memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); | |
501 | return count; | |
502 | } | |
503 | ||
15ad7cdc | 504 | static const struct file_operations proc_profile_operations = { |
1da177e4 LT |
505 | .read = read_profile, |
506 | .write = write_profile, | |
507 | }; | |
508 | ||
509 | #ifdef CONFIG_SMP | |
510 | static void __init profile_nop(void *unused) | |
511 | { | |
512 | } | |
513 | ||
514 | static int __init create_hash_tables(void) | |
515 | { | |
516 | int cpu; | |
517 | ||
518 | for_each_online_cpu(cpu) { | |
519 | int node = cpu_to_node(cpu); | |
520 | struct page *page; | |
521 | ||
fbd98167 CL |
522 | page = alloc_pages_node(node, |
523 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
524 | 0); | |
1da177e4 LT |
525 | if (!page) |
526 | goto out_cleanup; | |
527 | per_cpu(cpu_profile_hits, cpu)[1] | |
528 | = (struct profile_hit *)page_address(page); | |
fbd98167 CL |
529 | page = alloc_pages_node(node, |
530 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
531 | 0); | |
1da177e4 LT |
532 | if (!page) |
533 | goto out_cleanup; | |
534 | per_cpu(cpu_profile_hits, cpu)[0] | |
535 | = (struct profile_hit *)page_address(page); | |
536 | } | |
537 | return 0; | |
538 | out_cleanup: | |
539 | prof_on = 0; | |
d59dd462 | 540 | smp_mb(); |
1da177e4 LT |
541 | on_each_cpu(profile_nop, NULL, 0, 1); |
542 | for_each_online_cpu(cpu) { | |
543 | struct page *page; | |
544 | ||
545 | if (per_cpu(cpu_profile_hits, cpu)[0]) { | |
546 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
547 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
548 | __free_page(page); | |
549 | } | |
550 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
551 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
552 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
553 | __free_page(page); | |
554 | } | |
555 | } | |
556 | return -1; | |
557 | } | |
558 | #else | |
559 | #define create_hash_tables() ({ 0; }) | |
560 | #endif | |
561 | ||
562 | static int __init create_proc_profile(void) | |
563 | { | |
564 | struct proc_dir_entry *entry; | |
565 | ||
566 | if (!prof_on) | |
567 | return 0; | |
568 | if (create_hash_tables()) | |
569 | return -1; | |
570 | if (!(entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL))) | |
571 | return 0; | |
572 | entry->proc_fops = &proc_profile_operations; | |
573 | entry->size = (1+prof_len) * sizeof(atomic_t); | |
574 | hotcpu_notifier(profile_cpu_callback, 0); | |
575 | return 0; | |
576 | } | |
577 | module_init(create_proc_profile); | |
578 | #endif /* CONFIG_PROC_FS */ |