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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/kernel/profile.c | |
4 | * Simple profiling. Manages a direct-mapped profile hit count buffer, | |
5 | * with configurable resolution, support for restricting the cpus on | |
6 | * which profiling is done, and switching between cpu time and | |
7 | * schedule() calls via kernel command line parameters passed at boot. | |
8 | * | |
9 | * Scheduler profiling support, Arjan van de Ven and Ingo Molnar, | |
10 | * Red Hat, July 2004 | |
11 | * Consolidation of architecture support code for profiling, | |
6d49e352 | 12 | * Nadia Yvette Chambers, Oracle, July 2004 |
1da177e4 | 13 | * Amortized hit count accounting via per-cpu open-addressed hashtables |
6d49e352 NYC |
14 | * to resolve timer interrupt livelocks, Nadia Yvette Chambers, |
15 | * Oracle, 2004 | |
1da177e4 LT |
16 | */ |
17 | ||
9984de1a | 18 | #include <linux/export.h> |
1da177e4 | 19 | #include <linux/profile.h> |
57c8a661 | 20 | #include <linux/memblock.h> |
1da177e4 LT |
21 | #include <linux/notifier.h> |
22 | #include <linux/mm.h> | |
23 | #include <linux/cpumask.h> | |
24 | #include <linux/cpu.h> | |
1da177e4 | 25 | #include <linux/highmem.h> |
97d1f15b | 26 | #include <linux/mutex.h> |
22b8ce94 DH |
27 | #include <linux/slab.h> |
28 | #include <linux/vmalloc.h> | |
3905f9ad IM |
29 | #include <linux/sched/stat.h> |
30 | ||
1da177e4 | 31 | #include <asm/sections.h> |
7d12e780 | 32 | #include <asm/irq_regs.h> |
e8edc6e0 | 33 | #include <asm/ptrace.h> |
1da177e4 LT |
34 | |
35 | struct profile_hit { | |
36 | u32 pc, hits; | |
37 | }; | |
38 | #define PROFILE_GRPSHIFT 3 | |
39 | #define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) | |
40 | #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) | |
41 | #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) | |
42 | ||
1da177e4 | 43 | static atomic_t *prof_buffer; |
2d186afd PS |
44 | static unsigned long prof_len; |
45 | static unsigned short int prof_shift; | |
07031e14 | 46 | |
ece8a684 | 47 | int prof_on __read_mostly; |
07031e14 IM |
48 | EXPORT_SYMBOL_GPL(prof_on); |
49 | ||
c309b917 | 50 | static cpumask_var_t prof_cpu_mask; |
ade356b9 | 51 | #if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) |
1da177e4 LT |
52 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); |
53 | static DEFINE_PER_CPU(int, cpu_profile_flip); | |
97d1f15b | 54 | static DEFINE_MUTEX(profile_flip_mutex); |
1da177e4 LT |
55 | #endif /* CONFIG_SMP */ |
56 | ||
22b8ce94 | 57 | int profile_setup(char *str) |
1da177e4 | 58 | { |
f3da64d1 FF |
59 | static const char schedstr[] = "schedule"; |
60 | static const char sleepstr[] = "sleep"; | |
61 | static const char kvmstr[] = "kvm"; | |
1da177e4 LT |
62 | int par; |
63 | ||
ece8a684 | 64 | if (!strncmp(str, sleepstr, strlen(sleepstr))) { |
b3da2a73 | 65 | #ifdef CONFIG_SCHEDSTATS |
cb251765 | 66 | force_schedstat_enabled(); |
ece8a684 IM |
67 | prof_on = SLEEP_PROFILING; |
68 | if (str[strlen(sleepstr)] == ',') | |
69 | str += strlen(sleepstr) + 1; | |
70 | if (get_option(&str, &par)) | |
2d186afd PS |
71 | prof_shift = clamp(par, 0, BITS_PER_LONG - 1); |
72 | pr_info("kernel sleep profiling enabled (shift: %u)\n", | |
ece8a684 | 73 | prof_shift); |
b3da2a73 | 74 | #else |
aba871f1 | 75 | pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); |
b3da2a73 | 76 | #endif /* CONFIG_SCHEDSTATS */ |
a75acf85 | 77 | } else if (!strncmp(str, schedstr, strlen(schedstr))) { |
1da177e4 | 78 | prof_on = SCHED_PROFILING; |
dfaa9c94 WLII |
79 | if (str[strlen(schedstr)] == ',') |
80 | str += strlen(schedstr) + 1; | |
81 | if (get_option(&str, &par)) | |
2d186afd PS |
82 | prof_shift = clamp(par, 0, BITS_PER_LONG - 1); |
83 | pr_info("kernel schedule profiling enabled (shift: %u)\n", | |
dfaa9c94 | 84 | prof_shift); |
07031e14 IM |
85 | } else if (!strncmp(str, kvmstr, strlen(kvmstr))) { |
86 | prof_on = KVM_PROFILING; | |
87 | if (str[strlen(kvmstr)] == ',') | |
88 | str += strlen(kvmstr) + 1; | |
89 | if (get_option(&str, &par)) | |
2d186afd PS |
90 | prof_shift = clamp(par, 0, BITS_PER_LONG - 1); |
91 | pr_info("kernel KVM profiling enabled (shift: %u)\n", | |
07031e14 | 92 | prof_shift); |
dfaa9c94 | 93 | } else if (get_option(&str, &par)) { |
2d186afd | 94 | prof_shift = clamp(par, 0, BITS_PER_LONG - 1); |
1da177e4 | 95 | prof_on = CPU_PROFILING; |
2d186afd | 96 | pr_info("kernel profiling enabled (shift: %u)\n", |
1da177e4 LT |
97 | prof_shift); |
98 | } | |
99 | return 1; | |
100 | } | |
101 | __setup("profile=", profile_setup); | |
102 | ||
103 | ||
ce05fcc3 | 104 | int __ref profile_init(void) |
1da177e4 | 105 | { |
22b8ce94 | 106 | int buffer_bytes; |
1ad82fd5 | 107 | if (!prof_on) |
22b8ce94 | 108 | return 0; |
1ad82fd5 | 109 | |
1da177e4 LT |
110 | /* only text is profiled */ |
111 | prof_len = (_etext - _stext) >> prof_shift; | |
22b8ce94 | 112 | buffer_bytes = prof_len*sizeof(atomic_t); |
22b8ce94 | 113 | |
c309b917 RR |
114 | if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) |
115 | return -ENOMEM; | |
116 | ||
acd89579 HD |
117 | cpumask_copy(prof_cpu_mask, cpu_possible_mask); |
118 | ||
b62f495d | 119 | prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN); |
22b8ce94 DH |
120 | if (prof_buffer) |
121 | return 0; | |
122 | ||
b62f495d MG |
123 | prof_buffer = alloc_pages_exact(buffer_bytes, |
124 | GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN); | |
22b8ce94 DH |
125 | if (prof_buffer) |
126 | return 0; | |
127 | ||
559fa6e7 JJ |
128 | prof_buffer = vzalloc(buffer_bytes); |
129 | if (prof_buffer) | |
22b8ce94 DH |
130 | return 0; |
131 | ||
c309b917 | 132 | free_cpumask_var(prof_cpu_mask); |
22b8ce94 | 133 | return -ENOMEM; |
1da177e4 LT |
134 | } |
135 | ||
136 | /* Profile event notifications */ | |
1ad82fd5 | 137 | |
e041c683 AS |
138 | static BLOCKING_NOTIFIER_HEAD(task_exit_notifier); |
139 | static ATOMIC_NOTIFIER_HEAD(task_free_notifier); | |
140 | static BLOCKING_NOTIFIER_HEAD(munmap_notifier); | |
1ad82fd5 PC |
141 | |
142 | void profile_task_exit(struct task_struct *task) | |
1da177e4 | 143 | { |
e041c683 | 144 | blocking_notifier_call_chain(&task_exit_notifier, 0, task); |
1da177e4 | 145 | } |
1ad82fd5 PC |
146 | |
147 | int profile_handoff_task(struct task_struct *task) | |
1da177e4 LT |
148 | { |
149 | int ret; | |
e041c683 | 150 | ret = atomic_notifier_call_chain(&task_free_notifier, 0, task); |
1da177e4 LT |
151 | return (ret == NOTIFY_OK) ? 1 : 0; |
152 | } | |
153 | ||
154 | void profile_munmap(unsigned long addr) | |
155 | { | |
e041c683 | 156 | blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr); |
1da177e4 LT |
157 | } |
158 | ||
1ad82fd5 | 159 | int task_handoff_register(struct notifier_block *n) |
1da177e4 | 160 | { |
e041c683 | 161 | return atomic_notifier_chain_register(&task_free_notifier, n); |
1da177e4 | 162 | } |
1ad82fd5 | 163 | EXPORT_SYMBOL_GPL(task_handoff_register); |
1da177e4 | 164 | |
1ad82fd5 | 165 | int task_handoff_unregister(struct notifier_block *n) |
1da177e4 | 166 | { |
e041c683 | 167 | return atomic_notifier_chain_unregister(&task_free_notifier, n); |
1da177e4 | 168 | } |
1ad82fd5 | 169 | EXPORT_SYMBOL_GPL(task_handoff_unregister); |
1da177e4 | 170 | |
1ad82fd5 | 171 | int profile_event_register(enum profile_type type, struct notifier_block *n) |
1da177e4 LT |
172 | { |
173 | int err = -EINVAL; | |
1ad82fd5 | 174 | |
1da177e4 | 175 | switch (type) { |
1ad82fd5 PC |
176 | case PROFILE_TASK_EXIT: |
177 | err = blocking_notifier_chain_register( | |
178 | &task_exit_notifier, n); | |
179 | break; | |
180 | case PROFILE_MUNMAP: | |
181 | err = blocking_notifier_chain_register( | |
182 | &munmap_notifier, n); | |
183 | break; | |
1da177e4 | 184 | } |
1ad82fd5 | 185 | |
1da177e4 LT |
186 | return err; |
187 | } | |
1ad82fd5 | 188 | EXPORT_SYMBOL_GPL(profile_event_register); |
1da177e4 | 189 | |
1ad82fd5 | 190 | int profile_event_unregister(enum profile_type type, struct notifier_block *n) |
1da177e4 LT |
191 | { |
192 | int err = -EINVAL; | |
1ad82fd5 | 193 | |
1da177e4 | 194 | switch (type) { |
1ad82fd5 PC |
195 | case PROFILE_TASK_EXIT: |
196 | err = blocking_notifier_chain_unregister( | |
197 | &task_exit_notifier, n); | |
198 | break; | |
199 | case PROFILE_MUNMAP: | |
200 | err = blocking_notifier_chain_unregister( | |
201 | &munmap_notifier, n); | |
202 | break; | |
1da177e4 LT |
203 | } |
204 | ||
1da177e4 LT |
205 | return err; |
206 | } | |
1ad82fd5 | 207 | EXPORT_SYMBOL_GPL(profile_event_unregister); |
1da177e4 | 208 | |
ade356b9 | 209 | #if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) |
1da177e4 LT |
210 | /* |
211 | * Each cpu has a pair of open-addressed hashtables for pending | |
212 | * profile hits. read_profile() IPI's all cpus to request them | |
213 | * to flip buffers and flushes their contents to prof_buffer itself. | |
214 | * Flip requests are serialized by the profile_flip_mutex. The sole | |
215 | * use of having a second hashtable is for avoiding cacheline | |
216 | * contention that would otherwise happen during flushes of pending | |
217 | * profile hits required for the accuracy of reported profile hits | |
218 | * and so resurrect the interrupt livelock issue. | |
219 | * | |
220 | * The open-addressed hashtables are indexed by profile buffer slot | |
221 | * and hold the number of pending hits to that profile buffer slot on | |
222 | * a cpu in an entry. When the hashtable overflows, all pending hits | |
223 | * are accounted to their corresponding profile buffer slots with | |
224 | * atomic_add() and the hashtable emptied. As numerous pending hits | |
225 | * may be accounted to a profile buffer slot in a hashtable entry, | |
226 | * this amortizes a number of atomic profile buffer increments likely | |
227 | * to be far larger than the number of entries in the hashtable, | |
228 | * particularly given that the number of distinct profile buffer | |
229 | * positions to which hits are accounted during short intervals (e.g. | |
230 | * several seconds) is usually very small. Exclusion from buffer | |
231 | * flipping is provided by interrupt disablement (note that for | |
ece8a684 IM |
232 | * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from |
233 | * process context). | |
1da177e4 LT |
234 | * The hash function is meant to be lightweight as opposed to strong, |
235 | * and was vaguely inspired by ppc64 firmware-supported inverted | |
236 | * pagetable hash functions, but uses a full hashtable full of finite | |
237 | * collision chains, not just pairs of them. | |
238 | * | |
6d49e352 | 239 | * -- nyc |
1da177e4 LT |
240 | */ |
241 | static void __profile_flip_buffers(void *unused) | |
242 | { | |
243 | int cpu = smp_processor_id(); | |
244 | ||
245 | per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); | |
246 | } | |
247 | ||
248 | static void profile_flip_buffers(void) | |
249 | { | |
250 | int i, j, cpu; | |
251 | ||
97d1f15b | 252 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
253 | j = per_cpu(cpu_profile_flip, get_cpu()); |
254 | put_cpu(); | |
15c8b6c1 | 255 | on_each_cpu(__profile_flip_buffers, NULL, 1); |
1da177e4 LT |
256 | for_each_online_cpu(cpu) { |
257 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; | |
258 | for (i = 0; i < NR_PROFILE_HIT; ++i) { | |
259 | if (!hits[i].hits) { | |
260 | if (hits[i].pc) | |
261 | hits[i].pc = 0; | |
262 | continue; | |
263 | } | |
264 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
265 | hits[i].hits = hits[i].pc = 0; | |
266 | } | |
267 | } | |
97d1f15b | 268 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
269 | } |
270 | ||
271 | static void profile_discard_flip_buffers(void) | |
272 | { | |
273 | int i, cpu; | |
274 | ||
97d1f15b | 275 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
276 | i = per_cpu(cpu_profile_flip, get_cpu()); |
277 | put_cpu(); | |
15c8b6c1 | 278 | on_each_cpu(__profile_flip_buffers, NULL, 1); |
1da177e4 LT |
279 | for_each_online_cpu(cpu) { |
280 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; | |
281 | memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); | |
282 | } | |
97d1f15b | 283 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
284 | } |
285 | ||
6f7bd76f | 286 | static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
287 | { |
288 | unsigned long primary, secondary, flags, pc = (unsigned long)__pc; | |
289 | int i, j, cpu; | |
290 | struct profile_hit *hits; | |
291 | ||
1da177e4 LT |
292 | pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); |
293 | i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
294 | secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
295 | cpu = get_cpu(); | |
296 | hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; | |
297 | if (!hits) { | |
298 | put_cpu(); | |
299 | return; | |
300 | } | |
ece8a684 IM |
301 | /* |
302 | * We buffer the global profiler buffer into a per-CPU | |
303 | * queue and thus reduce the number of global (and possibly | |
304 | * NUMA-alien) accesses. The write-queue is self-coalescing: | |
305 | */ | |
1da177e4 LT |
306 | local_irq_save(flags); |
307 | do { | |
308 | for (j = 0; j < PROFILE_GRPSZ; ++j) { | |
309 | if (hits[i + j].pc == pc) { | |
ece8a684 | 310 | hits[i + j].hits += nr_hits; |
1da177e4 LT |
311 | goto out; |
312 | } else if (!hits[i + j].hits) { | |
313 | hits[i + j].pc = pc; | |
ece8a684 | 314 | hits[i + j].hits = nr_hits; |
1da177e4 LT |
315 | goto out; |
316 | } | |
317 | } | |
318 | i = (i + secondary) & (NR_PROFILE_HIT - 1); | |
319 | } while (i != primary); | |
ece8a684 IM |
320 | |
321 | /* | |
322 | * Add the current hit(s) and flush the write-queue out | |
323 | * to the global buffer: | |
324 | */ | |
325 | atomic_add(nr_hits, &prof_buffer[pc]); | |
1da177e4 LT |
326 | for (i = 0; i < NR_PROFILE_HIT; ++i) { |
327 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
328 | hits[i].pc = hits[i].hits = 0; | |
329 | } | |
330 | out: | |
331 | local_irq_restore(flags); | |
332 | put_cpu(); | |
333 | } | |
334 | ||
e722d8da | 335 | static int profile_dead_cpu(unsigned int cpu) |
1da177e4 | 336 | { |
1da177e4 | 337 | struct page *page; |
e722d8da | 338 | int i; |
1da177e4 | 339 | |
ef70eff9 | 340 | if (cpumask_available(prof_cpu_mask)) |
e722d8da SAS |
341 | cpumask_clear_cpu(cpu, prof_cpu_mask); |
342 | ||
343 | for (i = 0; i < 2; i++) { | |
344 | if (per_cpu(cpu_profile_hits, cpu)[i]) { | |
345 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]); | |
346 | per_cpu(cpu_profile_hits, cpu)[i] = NULL; | |
1da177e4 LT |
347 | __free_page(page); |
348 | } | |
e722d8da SAS |
349 | } |
350 | return 0; | |
351 | } | |
352 | ||
353 | static int profile_prepare_cpu(unsigned int cpu) | |
354 | { | |
355 | int i, node = cpu_to_mem(cpu); | |
356 | struct page *page; | |
357 | ||
358 | per_cpu(cpu_profile_flip, cpu) = 0; | |
359 | ||
360 | for (i = 0; i < 2; i++) { | |
361 | if (per_cpu(cpu_profile_hits, cpu)[i]) | |
362 | continue; | |
363 | ||
364 | page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); | |
365 | if (!page) { | |
366 | profile_dead_cpu(cpu); | |
367 | return -ENOMEM; | |
1da177e4 | 368 | } |
e722d8da SAS |
369 | per_cpu(cpu_profile_hits, cpu)[i] = page_address(page); |
370 | ||
1da177e4 | 371 | } |
e722d8da SAS |
372 | return 0; |
373 | } | |
374 | ||
375 | static int profile_online_cpu(unsigned int cpu) | |
376 | { | |
ef70eff9 | 377 | if (cpumask_available(prof_cpu_mask)) |
e722d8da SAS |
378 | cpumask_set_cpu(cpu, prof_cpu_mask); |
379 | ||
380 | return 0; | |
1da177e4 | 381 | } |
e722d8da | 382 | |
1da177e4 LT |
383 | #else /* !CONFIG_SMP */ |
384 | #define profile_flip_buffers() do { } while (0) | |
385 | #define profile_discard_flip_buffers() do { } while (0) | |
386 | ||
6f7bd76f | 387 | static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
388 | { |
389 | unsigned long pc; | |
1da177e4 | 390 | pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; |
ece8a684 | 391 | atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); |
1da177e4 LT |
392 | } |
393 | #endif /* !CONFIG_SMP */ | |
6f7bd76f RM |
394 | |
395 | void profile_hits(int type, void *__pc, unsigned int nr_hits) | |
396 | { | |
397 | if (prof_on != type || !prof_buffer) | |
398 | return; | |
399 | do_profile_hits(type, __pc, nr_hits); | |
400 | } | |
bbe1a59b AM |
401 | EXPORT_SYMBOL_GPL(profile_hits); |
402 | ||
7d12e780 | 403 | void profile_tick(int type) |
1da177e4 | 404 | { |
7d12e780 DH |
405 | struct pt_regs *regs = get_irq_regs(); |
406 | ||
ef70eff9 | 407 | if (!user_mode(regs) && cpumask_available(prof_cpu_mask) && |
c309b917 | 408 | cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) |
1da177e4 LT |
409 | profile_hit(type, (void *)profile_pc(regs)); |
410 | } | |
411 | ||
412 | #ifdef CONFIG_PROC_FS | |
413 | #include <linux/proc_fs.h> | |
583a22e7 | 414 | #include <linux/seq_file.h> |
7c0f6ba6 | 415 | #include <linux/uaccess.h> |
1da177e4 | 416 | |
583a22e7 | 417 | static int prof_cpu_mask_proc_show(struct seq_file *m, void *v) |
1da177e4 | 418 | { |
ccbd59c1 | 419 | seq_printf(m, "%*pb\n", cpumask_pr_args(prof_cpu_mask)); |
583a22e7 AD |
420 | return 0; |
421 | } | |
422 | ||
423 | static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file) | |
424 | { | |
425 | return single_open(file, prof_cpu_mask_proc_show, NULL); | |
1da177e4 LT |
426 | } |
427 | ||
583a22e7 AD |
428 | static ssize_t prof_cpu_mask_proc_write(struct file *file, |
429 | const char __user *buffer, size_t count, loff_t *pos) | |
1da177e4 | 430 | { |
c309b917 | 431 | cpumask_var_t new_value; |
583a22e7 | 432 | int err; |
1da177e4 | 433 | |
c5e3a411 | 434 | if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) |
c309b917 | 435 | return -ENOMEM; |
1da177e4 | 436 | |
c309b917 RR |
437 | err = cpumask_parse_user(buffer, count, new_value); |
438 | if (!err) { | |
583a22e7 AD |
439 | cpumask_copy(prof_cpu_mask, new_value); |
440 | err = count; | |
c309b917 RR |
441 | } |
442 | free_cpumask_var(new_value); | |
443 | return err; | |
1da177e4 LT |
444 | } |
445 | ||
97a32539 AD |
446 | static const struct proc_ops prof_cpu_mask_proc_ops = { |
447 | .proc_open = prof_cpu_mask_proc_open, | |
448 | .proc_read = seq_read, | |
449 | .proc_lseek = seq_lseek, | |
450 | .proc_release = single_release, | |
451 | .proc_write = prof_cpu_mask_proc_write, | |
583a22e7 AD |
452 | }; |
453 | ||
fbd387ae | 454 | void create_prof_cpu_mask(void) |
1da177e4 | 455 | { |
1da177e4 | 456 | /* create /proc/irq/prof_cpu_mask */ |
97a32539 | 457 | proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_ops); |
1da177e4 LT |
458 | } |
459 | ||
460 | /* | |
461 | * This function accesses profiling information. The returned data is | |
462 | * binary: the sampling step and the actual contents of the profile | |
463 | * buffer. Use of the program readprofile is recommended in order to | |
464 | * get meaningful info out of these data. | |
465 | */ | |
466 | static ssize_t | |
467 | read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
468 | { | |
469 | unsigned long p = *ppos; | |
470 | ssize_t read; | |
1ad82fd5 | 471 | char *pnt; |
2d186afd | 472 | unsigned long sample_step = 1UL << prof_shift; |
1da177e4 LT |
473 | |
474 | profile_flip_buffers(); | |
475 | if (p >= (prof_len+1)*sizeof(unsigned int)) | |
476 | return 0; | |
477 | if (count > (prof_len+1)*sizeof(unsigned int) - p) | |
478 | count = (prof_len+1)*sizeof(unsigned int) - p; | |
479 | read = 0; | |
480 | ||
481 | while (p < sizeof(unsigned int) && count > 0) { | |
1ad82fd5 | 482 | if (put_user(*((char *)(&sample_step)+p), buf)) |
064b022c | 483 | return -EFAULT; |
1da177e4 LT |
484 | buf++; p++; count--; read++; |
485 | } | |
486 | pnt = (char *)prof_buffer + p - sizeof(atomic_t); | |
1ad82fd5 | 487 | if (copy_to_user(buf, (void *)pnt, count)) |
1da177e4 LT |
488 | return -EFAULT; |
489 | read += count; | |
490 | *ppos += read; | |
491 | return read; | |
492 | } | |
493 | ||
494 | /* | |
495 | * Writing to /proc/profile resets the counters | |
496 | * | |
497 | * Writing a 'profiling multiplier' value into it also re-sets the profiling | |
498 | * interrupt frequency, on architectures that support this. | |
499 | */ | |
500 | static ssize_t write_profile(struct file *file, const char __user *buf, | |
501 | size_t count, loff_t *ppos) | |
502 | { | |
503 | #ifdef CONFIG_SMP | |
1ad82fd5 | 504 | extern int setup_profiling_timer(unsigned int multiplier); |
1da177e4 LT |
505 | |
506 | if (count == sizeof(int)) { | |
507 | unsigned int multiplier; | |
508 | ||
509 | if (copy_from_user(&multiplier, buf, sizeof(int))) | |
510 | return -EFAULT; | |
511 | ||
512 | if (setup_profiling_timer(multiplier)) | |
513 | return -EINVAL; | |
514 | } | |
515 | #endif | |
516 | profile_discard_flip_buffers(); | |
517 | memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); | |
518 | return count; | |
519 | } | |
520 | ||
97a32539 AD |
521 | static const struct proc_ops profile_proc_ops = { |
522 | .proc_read = read_profile, | |
523 | .proc_write = write_profile, | |
524 | .proc_lseek = default_llseek, | |
1da177e4 LT |
525 | }; |
526 | ||
e722d8da | 527 | int __ref create_proc_profile(void) |
1da177e4 | 528 | { |
e722d8da SAS |
529 | struct proc_dir_entry *entry; |
530 | #ifdef CONFIG_SMP | |
531 | enum cpuhp_state online_state; | |
1da177e4 LT |
532 | #endif |
533 | ||
c270a817 | 534 | int err = 0; |
1da177e4 LT |
535 | |
536 | if (!prof_on) | |
537 | return 0; | |
e722d8da SAS |
538 | #ifdef CONFIG_SMP |
539 | err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE", | |
540 | profile_prepare_cpu, profile_dead_cpu); | |
541 | if (err) | |
542 | return err; | |
543 | ||
544 | err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PROFILE_ONLINE", | |
545 | profile_online_cpu, NULL); | |
546 | if (err < 0) | |
547 | goto err_state_prep; | |
548 | online_state = err; | |
549 | err = 0; | |
550 | #endif | |
c33fff0a | 551 | entry = proc_create("profile", S_IWUSR | S_IRUGO, |
97a32539 | 552 | NULL, &profile_proc_ops); |
1ad82fd5 | 553 | if (!entry) |
e722d8da | 554 | goto err_state_onl; |
271a15ea | 555 | proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); |
c270a817 | 556 | |
e722d8da SAS |
557 | return err; |
558 | err_state_onl: | |
559 | #ifdef CONFIG_SMP | |
560 | cpuhp_remove_state(online_state); | |
561 | err_state_prep: | |
562 | cpuhp_remove_state(CPUHP_PROFILE_PREPARE); | |
563 | #endif | |
c270a817 | 564 | return err; |
1da177e4 | 565 | } |
c96d6660 | 566 | subsys_initcall(create_proc_profile); |
1da177e4 | 567 | #endif /* CONFIG_PROC_FS */ |