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Commit | Line | Data |
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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> | |
1da177e4 | 23 | #include <linux/highmem.h> |
97d1f15b | 24 | #include <linux/mutex.h> |
22b8ce94 DH |
25 | #include <linux/slab.h> |
26 | #include <linux/vmalloc.h> | |
1da177e4 | 27 | #include <asm/sections.h> |
7d12e780 | 28 | #include <asm/irq_regs.h> |
e8edc6e0 | 29 | #include <asm/ptrace.h> |
1da177e4 LT |
30 | |
31 | struct profile_hit { | |
32 | u32 pc, hits; | |
33 | }; | |
34 | #define PROFILE_GRPSHIFT 3 | |
35 | #define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) | |
36 | #define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) | |
37 | #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) | |
38 | ||
39 | /* Oprofile timer tick hook */ | |
b012d346 | 40 | static int (*timer_hook)(struct pt_regs *) __read_mostly; |
1da177e4 LT |
41 | |
42 | static atomic_t *prof_buffer; | |
43 | static unsigned long prof_len, prof_shift; | |
07031e14 | 44 | |
ece8a684 | 45 | int prof_on __read_mostly; |
07031e14 IM |
46 | EXPORT_SYMBOL_GPL(prof_on); |
47 | ||
c309b917 | 48 | static cpumask_var_t prof_cpu_mask; |
1da177e4 LT |
49 | #ifdef CONFIG_SMP |
50 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); | |
51 | static DEFINE_PER_CPU(int, cpu_profile_flip); | |
97d1f15b | 52 | static DEFINE_MUTEX(profile_flip_mutex); |
1da177e4 LT |
53 | #endif /* CONFIG_SMP */ |
54 | ||
22b8ce94 | 55 | int profile_setup(char *str) |
1da177e4 | 56 | { |
22b8ce94 DH |
57 | static char schedstr[] = "schedule"; |
58 | static char sleepstr[] = "sleep"; | |
59 | static char kvmstr[] = "kvm"; | |
1da177e4 LT |
60 | int par; |
61 | ||
ece8a684 | 62 | if (!strncmp(str, sleepstr, strlen(sleepstr))) { |
b3da2a73 | 63 | #ifdef CONFIG_SCHEDSTATS |
ece8a684 IM |
64 | prof_on = SLEEP_PROFILING; |
65 | if (str[strlen(sleepstr)] == ',') | |
66 | str += strlen(sleepstr) + 1; | |
67 | if (get_option(&str, &par)) | |
68 | prof_shift = par; | |
69 | printk(KERN_INFO | |
70 | "kernel sleep profiling enabled (shift: %ld)\n", | |
71 | prof_shift); | |
b3da2a73 MG |
72 | #else |
73 | printk(KERN_WARNING | |
74 | "kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); | |
75 | #endif /* CONFIG_SCHEDSTATS */ | |
a75acf85 | 76 | } else if (!strncmp(str, schedstr, strlen(schedstr))) { |
1da177e4 | 77 | prof_on = SCHED_PROFILING; |
dfaa9c94 WLII |
78 | if (str[strlen(schedstr)] == ',') |
79 | str += strlen(schedstr) + 1; | |
80 | if (get_option(&str, &par)) | |
81 | prof_shift = par; | |
82 | printk(KERN_INFO | |
83 | "kernel schedule profiling enabled (shift: %ld)\n", | |
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)) | |
90 | prof_shift = par; | |
91 | printk(KERN_INFO | |
92 | "kernel KVM profiling enabled (shift: %ld)\n", | |
93 | prof_shift); | |
dfaa9c94 | 94 | } else if (get_option(&str, &par)) { |
1da177e4 LT |
95 | prof_shift = par; |
96 | prof_on = CPU_PROFILING; | |
97 | printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n", | |
98 | prof_shift); | |
99 | } | |
100 | return 1; | |
101 | } | |
102 | __setup("profile=", profile_setup); | |
103 | ||
104 | ||
ce05fcc3 | 105 | int __ref profile_init(void) |
1da177e4 | 106 | { |
22b8ce94 | 107 | int buffer_bytes; |
1ad82fd5 | 108 | if (!prof_on) |
22b8ce94 | 109 | return 0; |
1ad82fd5 | 110 | |
1da177e4 LT |
111 | /* only text is profiled */ |
112 | prof_len = (_etext - _stext) >> prof_shift; | |
22b8ce94 DH |
113 | buffer_bytes = prof_len*sizeof(atomic_t); |
114 | if (!slab_is_available()) { | |
115 | prof_buffer = alloc_bootmem(buffer_bytes); | |
c309b917 | 116 | alloc_bootmem_cpumask_var(&prof_cpu_mask); |
22b8ce94 DH |
117 | return 0; |
118 | } | |
119 | ||
c309b917 RR |
120 | if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) |
121 | return -ENOMEM; | |
122 | ||
22b8ce94 DH |
123 | prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL); |
124 | if (prof_buffer) | |
125 | return 0; | |
126 | ||
127 | prof_buffer = alloc_pages_exact(buffer_bytes, GFP_KERNEL|__GFP_ZERO); | |
128 | if (prof_buffer) | |
129 | return 0; | |
130 | ||
131 | prof_buffer = vmalloc(buffer_bytes); | |
132 | if (prof_buffer) | |
133 | return 0; | |
134 | ||
c309b917 | 135 | free_cpumask_var(prof_cpu_mask); |
22b8ce94 | 136 | return -ENOMEM; |
1da177e4 LT |
137 | } |
138 | ||
139 | /* Profile event notifications */ | |
1ad82fd5 | 140 | |
e041c683 AS |
141 | static BLOCKING_NOTIFIER_HEAD(task_exit_notifier); |
142 | static ATOMIC_NOTIFIER_HEAD(task_free_notifier); | |
143 | static BLOCKING_NOTIFIER_HEAD(munmap_notifier); | |
1ad82fd5 PC |
144 | |
145 | void profile_task_exit(struct task_struct *task) | |
1da177e4 | 146 | { |
e041c683 | 147 | blocking_notifier_call_chain(&task_exit_notifier, 0, task); |
1da177e4 | 148 | } |
1ad82fd5 PC |
149 | |
150 | int profile_handoff_task(struct task_struct *task) | |
1da177e4 LT |
151 | { |
152 | int ret; | |
e041c683 | 153 | ret = atomic_notifier_call_chain(&task_free_notifier, 0, task); |
1da177e4 LT |
154 | return (ret == NOTIFY_OK) ? 1 : 0; |
155 | } | |
156 | ||
157 | void profile_munmap(unsigned long addr) | |
158 | { | |
e041c683 | 159 | blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr); |
1da177e4 LT |
160 | } |
161 | ||
1ad82fd5 | 162 | int task_handoff_register(struct notifier_block *n) |
1da177e4 | 163 | { |
e041c683 | 164 | return atomic_notifier_chain_register(&task_free_notifier, n); |
1da177e4 | 165 | } |
1ad82fd5 | 166 | EXPORT_SYMBOL_GPL(task_handoff_register); |
1da177e4 | 167 | |
1ad82fd5 | 168 | int task_handoff_unregister(struct notifier_block *n) |
1da177e4 | 169 | { |
e041c683 | 170 | return atomic_notifier_chain_unregister(&task_free_notifier, n); |
1da177e4 | 171 | } |
1ad82fd5 | 172 | EXPORT_SYMBOL_GPL(task_handoff_unregister); |
1da177e4 | 173 | |
1ad82fd5 | 174 | int profile_event_register(enum profile_type type, struct notifier_block *n) |
1da177e4 LT |
175 | { |
176 | int err = -EINVAL; | |
1ad82fd5 | 177 | |
1da177e4 | 178 | switch (type) { |
1ad82fd5 PC |
179 | case PROFILE_TASK_EXIT: |
180 | err = blocking_notifier_chain_register( | |
181 | &task_exit_notifier, n); | |
182 | break; | |
183 | case PROFILE_MUNMAP: | |
184 | err = blocking_notifier_chain_register( | |
185 | &munmap_notifier, n); | |
186 | break; | |
1da177e4 | 187 | } |
1ad82fd5 | 188 | |
1da177e4 LT |
189 | return err; |
190 | } | |
1ad82fd5 | 191 | EXPORT_SYMBOL_GPL(profile_event_register); |
1da177e4 | 192 | |
1ad82fd5 | 193 | int profile_event_unregister(enum profile_type type, struct notifier_block *n) |
1da177e4 LT |
194 | { |
195 | int err = -EINVAL; | |
1ad82fd5 | 196 | |
1da177e4 | 197 | switch (type) { |
1ad82fd5 PC |
198 | case PROFILE_TASK_EXIT: |
199 | err = blocking_notifier_chain_unregister( | |
200 | &task_exit_notifier, n); | |
201 | break; | |
202 | case PROFILE_MUNMAP: | |
203 | err = blocking_notifier_chain_unregister( | |
204 | &munmap_notifier, n); | |
205 | break; | |
1da177e4 LT |
206 | } |
207 | ||
1da177e4 LT |
208 | return err; |
209 | } | |
1ad82fd5 | 210 | EXPORT_SYMBOL_GPL(profile_event_unregister); |
1da177e4 LT |
211 | |
212 | int register_timer_hook(int (*hook)(struct pt_regs *)) | |
213 | { | |
214 | if (timer_hook) | |
215 | return -EBUSY; | |
216 | timer_hook = hook; | |
217 | return 0; | |
218 | } | |
1ad82fd5 | 219 | EXPORT_SYMBOL_GPL(register_timer_hook); |
1da177e4 LT |
220 | |
221 | void unregister_timer_hook(int (*hook)(struct pt_regs *)) | |
222 | { | |
223 | WARN_ON(hook != timer_hook); | |
224 | timer_hook = NULL; | |
225 | /* make sure all CPUs see the NULL hook */ | |
fbd568a3 | 226 | synchronize_sched(); /* Allow ongoing interrupts to complete. */ |
1da177e4 | 227 | } |
1da177e4 | 228 | EXPORT_SYMBOL_GPL(unregister_timer_hook); |
1da177e4 | 229 | |
1da177e4 LT |
230 | |
231 | #ifdef CONFIG_SMP | |
232 | /* | |
233 | * Each cpu has a pair of open-addressed hashtables for pending | |
234 | * profile hits. read_profile() IPI's all cpus to request them | |
235 | * to flip buffers and flushes their contents to prof_buffer itself. | |
236 | * Flip requests are serialized by the profile_flip_mutex. The sole | |
237 | * use of having a second hashtable is for avoiding cacheline | |
238 | * contention that would otherwise happen during flushes of pending | |
239 | * profile hits required for the accuracy of reported profile hits | |
240 | * and so resurrect the interrupt livelock issue. | |
241 | * | |
242 | * The open-addressed hashtables are indexed by profile buffer slot | |
243 | * and hold the number of pending hits to that profile buffer slot on | |
244 | * a cpu in an entry. When the hashtable overflows, all pending hits | |
245 | * are accounted to their corresponding profile buffer slots with | |
246 | * atomic_add() and the hashtable emptied. As numerous pending hits | |
247 | * may be accounted to a profile buffer slot in a hashtable entry, | |
248 | * this amortizes a number of atomic profile buffer increments likely | |
249 | * to be far larger than the number of entries in the hashtable, | |
250 | * particularly given that the number of distinct profile buffer | |
251 | * positions to which hits are accounted during short intervals (e.g. | |
252 | * several seconds) is usually very small. Exclusion from buffer | |
253 | * flipping is provided by interrupt disablement (note that for | |
ece8a684 IM |
254 | * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from |
255 | * process context). | |
1da177e4 LT |
256 | * The hash function is meant to be lightweight as opposed to strong, |
257 | * and was vaguely inspired by ppc64 firmware-supported inverted | |
258 | * pagetable hash functions, but uses a full hashtable full of finite | |
259 | * collision chains, not just pairs of them. | |
260 | * | |
261 | * -- wli | |
262 | */ | |
263 | static void __profile_flip_buffers(void *unused) | |
264 | { | |
265 | int cpu = smp_processor_id(); | |
266 | ||
267 | per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); | |
268 | } | |
269 | ||
270 | static void profile_flip_buffers(void) | |
271 | { | |
272 | int i, j, cpu; | |
273 | ||
97d1f15b | 274 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
275 | j = per_cpu(cpu_profile_flip, get_cpu()); |
276 | put_cpu(); | |
15c8b6c1 | 277 | on_each_cpu(__profile_flip_buffers, NULL, 1); |
1da177e4 LT |
278 | for_each_online_cpu(cpu) { |
279 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; | |
280 | for (i = 0; i < NR_PROFILE_HIT; ++i) { | |
281 | if (!hits[i].hits) { | |
282 | if (hits[i].pc) | |
283 | hits[i].pc = 0; | |
284 | continue; | |
285 | } | |
286 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
287 | hits[i].hits = hits[i].pc = 0; | |
288 | } | |
289 | } | |
97d1f15b | 290 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
291 | } |
292 | ||
293 | static void profile_discard_flip_buffers(void) | |
294 | { | |
295 | int i, cpu; | |
296 | ||
97d1f15b | 297 | mutex_lock(&profile_flip_mutex); |
1da177e4 LT |
298 | i = per_cpu(cpu_profile_flip, get_cpu()); |
299 | put_cpu(); | |
15c8b6c1 | 300 | on_each_cpu(__profile_flip_buffers, NULL, 1); |
1da177e4 LT |
301 | for_each_online_cpu(cpu) { |
302 | struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; | |
303 | memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); | |
304 | } | |
97d1f15b | 305 | mutex_unlock(&profile_flip_mutex); |
1da177e4 LT |
306 | } |
307 | ||
ece8a684 | 308 | void profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
309 | { |
310 | unsigned long primary, secondary, flags, pc = (unsigned long)__pc; | |
311 | int i, j, cpu; | |
312 | struct profile_hit *hits; | |
313 | ||
314 | if (prof_on != type || !prof_buffer) | |
315 | return; | |
316 | pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); | |
317 | i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
318 | secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; | |
319 | cpu = get_cpu(); | |
320 | hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; | |
321 | if (!hits) { | |
322 | put_cpu(); | |
323 | return; | |
324 | } | |
ece8a684 IM |
325 | /* |
326 | * We buffer the global profiler buffer into a per-CPU | |
327 | * queue and thus reduce the number of global (and possibly | |
328 | * NUMA-alien) accesses. The write-queue is self-coalescing: | |
329 | */ | |
1da177e4 LT |
330 | local_irq_save(flags); |
331 | do { | |
332 | for (j = 0; j < PROFILE_GRPSZ; ++j) { | |
333 | if (hits[i + j].pc == pc) { | |
ece8a684 | 334 | hits[i + j].hits += nr_hits; |
1da177e4 LT |
335 | goto out; |
336 | } else if (!hits[i + j].hits) { | |
337 | hits[i + j].pc = pc; | |
ece8a684 | 338 | hits[i + j].hits = nr_hits; |
1da177e4 LT |
339 | goto out; |
340 | } | |
341 | } | |
342 | i = (i + secondary) & (NR_PROFILE_HIT - 1); | |
343 | } while (i != primary); | |
ece8a684 IM |
344 | |
345 | /* | |
346 | * Add the current hit(s) and flush the write-queue out | |
347 | * to the global buffer: | |
348 | */ | |
349 | atomic_add(nr_hits, &prof_buffer[pc]); | |
1da177e4 LT |
350 | for (i = 0; i < NR_PROFILE_HIT; ++i) { |
351 | atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); | |
352 | hits[i].pc = hits[i].hits = 0; | |
353 | } | |
354 | out: | |
355 | local_irq_restore(flags); | |
356 | put_cpu(); | |
357 | } | |
358 | ||
84196414 | 359 | static int __cpuinit profile_cpu_callback(struct notifier_block *info, |
1da177e4 LT |
360 | unsigned long action, void *__cpu) |
361 | { | |
362 | int node, cpu = (unsigned long)__cpu; | |
363 | struct page *page; | |
364 | ||
365 | switch (action) { | |
366 | case CPU_UP_PREPARE: | |
8bb78442 | 367 | case CPU_UP_PREPARE_FROZEN: |
1da177e4 LT |
368 | node = cpu_to_node(cpu); |
369 | per_cpu(cpu_profile_flip, cpu) = 0; | |
370 | if (!per_cpu(cpu_profile_hits, cpu)[1]) { | |
fbd98167 | 371 | page = alloc_pages_node(node, |
4199cfa0 | 372 | GFP_KERNEL | __GFP_ZERO, |
fbd98167 | 373 | 0); |
1da177e4 LT |
374 | if (!page) |
375 | return NOTIFY_BAD; | |
376 | per_cpu(cpu_profile_hits, cpu)[1] = page_address(page); | |
377 | } | |
378 | if (!per_cpu(cpu_profile_hits, cpu)[0]) { | |
fbd98167 | 379 | page = alloc_pages_node(node, |
4199cfa0 | 380 | GFP_KERNEL | __GFP_ZERO, |
fbd98167 | 381 | 0); |
1da177e4 LT |
382 | if (!page) |
383 | goto out_free; | |
384 | per_cpu(cpu_profile_hits, cpu)[0] = page_address(page); | |
385 | } | |
386 | break; | |
1ad82fd5 | 387 | out_free: |
1da177e4 LT |
388 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); |
389 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
390 | __free_page(page); | |
391 | return NOTIFY_BAD; | |
392 | case CPU_ONLINE: | |
8bb78442 | 393 | case CPU_ONLINE_FROZEN: |
c309b917 RR |
394 | if (prof_cpu_mask != NULL) |
395 | cpumask_set_cpu(cpu, prof_cpu_mask); | |
1da177e4 LT |
396 | break; |
397 | case CPU_UP_CANCELED: | |
8bb78442 | 398 | case CPU_UP_CANCELED_FROZEN: |
1da177e4 | 399 | case CPU_DEAD: |
8bb78442 | 400 | case CPU_DEAD_FROZEN: |
c309b917 RR |
401 | if (prof_cpu_mask != NULL) |
402 | cpumask_clear_cpu(cpu, prof_cpu_mask); | |
1da177e4 LT |
403 | if (per_cpu(cpu_profile_hits, cpu)[0]) { |
404 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
405 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
406 | __free_page(page); | |
407 | } | |
408 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
409 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
410 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
411 | __free_page(page); | |
412 | } | |
413 | break; | |
414 | } | |
415 | return NOTIFY_OK; | |
416 | } | |
1da177e4 LT |
417 | #else /* !CONFIG_SMP */ |
418 | #define profile_flip_buffers() do { } while (0) | |
419 | #define profile_discard_flip_buffers() do { } while (0) | |
02316067 | 420 | #define profile_cpu_callback NULL |
1da177e4 | 421 | |
ece8a684 | 422 | void profile_hits(int type, void *__pc, unsigned int nr_hits) |
1da177e4 LT |
423 | { |
424 | unsigned long pc; | |
425 | ||
426 | if (prof_on != type || !prof_buffer) | |
427 | return; | |
428 | pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; | |
ece8a684 | 429 | atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); |
1da177e4 LT |
430 | } |
431 | #endif /* !CONFIG_SMP */ | |
bbe1a59b AM |
432 | EXPORT_SYMBOL_GPL(profile_hits); |
433 | ||
7d12e780 | 434 | void profile_tick(int type) |
1da177e4 | 435 | { |
7d12e780 DH |
436 | struct pt_regs *regs = get_irq_regs(); |
437 | ||
1da177e4 LT |
438 | if (type == CPU_PROFILING && timer_hook) |
439 | timer_hook(regs); | |
c309b917 RR |
440 | if (!user_mode(regs) && prof_cpu_mask != NULL && |
441 | cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) | |
1da177e4 LT |
442 | profile_hit(type, (void *)profile_pc(regs)); |
443 | } | |
444 | ||
445 | #ifdef CONFIG_PROC_FS | |
446 | #include <linux/proc_fs.h> | |
447 | #include <asm/uaccess.h> | |
1da177e4 | 448 | |
1ad82fd5 | 449 | static int prof_cpu_mask_read_proc(char *page, char **start, off_t off, |
1da177e4 LT |
450 | int count, int *eof, void *data) |
451 | { | |
c309b917 | 452 | int len = cpumask_scnprintf(page, count, data); |
1da177e4 LT |
453 | if (count - len < 2) |
454 | return -EINVAL; | |
455 | len += sprintf(page + len, "\n"); | |
456 | return len; | |
457 | } | |
458 | ||
1ad82fd5 PC |
459 | static int prof_cpu_mask_write_proc(struct file *file, |
460 | const char __user *buffer, unsigned long count, void *data) | |
1da177e4 | 461 | { |
c309b917 | 462 | struct cpumask *mask = data; |
1da177e4 | 463 | unsigned long full_count = count, err; |
c309b917 | 464 | cpumask_var_t new_value; |
1da177e4 | 465 | |
c309b917 RR |
466 | if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) |
467 | return -ENOMEM; | |
1da177e4 | 468 | |
c309b917 RR |
469 | err = cpumask_parse_user(buffer, count, new_value); |
470 | if (!err) { | |
471 | cpumask_copy(mask, new_value); | |
472 | err = full_count; | |
473 | } | |
474 | free_cpumask_var(new_value); | |
475 | return err; | |
1da177e4 LT |
476 | } |
477 | ||
478 | void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) | |
479 | { | |
480 | struct proc_dir_entry *entry; | |
481 | ||
482 | /* create /proc/irq/prof_cpu_mask */ | |
1ad82fd5 PC |
483 | entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir); |
484 | if (!entry) | |
1da177e4 | 485 | return; |
c309b917 | 486 | entry->data = prof_cpu_mask; |
1da177e4 LT |
487 | entry->read_proc = prof_cpu_mask_read_proc; |
488 | entry->write_proc = prof_cpu_mask_write_proc; | |
489 | } | |
490 | ||
491 | /* | |
492 | * This function accesses profiling information. The returned data is | |
493 | * binary: the sampling step and the actual contents of the profile | |
494 | * buffer. Use of the program readprofile is recommended in order to | |
495 | * get meaningful info out of these data. | |
496 | */ | |
497 | static ssize_t | |
498 | read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
499 | { | |
500 | unsigned long p = *ppos; | |
501 | ssize_t read; | |
1ad82fd5 | 502 | char *pnt; |
1da177e4 LT |
503 | unsigned int sample_step = 1 << prof_shift; |
504 | ||
505 | profile_flip_buffers(); | |
506 | if (p >= (prof_len+1)*sizeof(unsigned int)) | |
507 | return 0; | |
508 | if (count > (prof_len+1)*sizeof(unsigned int) - p) | |
509 | count = (prof_len+1)*sizeof(unsigned int) - p; | |
510 | read = 0; | |
511 | ||
512 | while (p < sizeof(unsigned int) && count > 0) { | |
1ad82fd5 | 513 | if (put_user(*((char *)(&sample_step)+p), buf)) |
064b022c | 514 | return -EFAULT; |
1da177e4 LT |
515 | buf++; p++; count--; read++; |
516 | } | |
517 | pnt = (char *)prof_buffer + p - sizeof(atomic_t); | |
1ad82fd5 | 518 | if (copy_to_user(buf, (void *)pnt, count)) |
1da177e4 LT |
519 | return -EFAULT; |
520 | read += count; | |
521 | *ppos += read; | |
522 | return read; | |
523 | } | |
524 | ||
525 | /* | |
526 | * Writing to /proc/profile resets the counters | |
527 | * | |
528 | * Writing a 'profiling multiplier' value into it also re-sets the profiling | |
529 | * interrupt frequency, on architectures that support this. | |
530 | */ | |
531 | static ssize_t write_profile(struct file *file, const char __user *buf, | |
532 | size_t count, loff_t *ppos) | |
533 | { | |
534 | #ifdef CONFIG_SMP | |
1ad82fd5 | 535 | extern int setup_profiling_timer(unsigned int multiplier); |
1da177e4 LT |
536 | |
537 | if (count == sizeof(int)) { | |
538 | unsigned int multiplier; | |
539 | ||
540 | if (copy_from_user(&multiplier, buf, sizeof(int))) | |
541 | return -EFAULT; | |
542 | ||
543 | if (setup_profiling_timer(multiplier)) | |
544 | return -EINVAL; | |
545 | } | |
546 | #endif | |
547 | profile_discard_flip_buffers(); | |
548 | memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); | |
549 | return count; | |
550 | } | |
551 | ||
15ad7cdc | 552 | static const struct file_operations proc_profile_operations = { |
1da177e4 LT |
553 | .read = read_profile, |
554 | .write = write_profile, | |
555 | }; | |
556 | ||
557 | #ifdef CONFIG_SMP | |
60a51513 | 558 | static void profile_nop(void *unused) |
1da177e4 LT |
559 | { |
560 | } | |
561 | ||
22b8ce94 | 562 | static int create_hash_tables(void) |
1da177e4 LT |
563 | { |
564 | int cpu; | |
565 | ||
566 | for_each_online_cpu(cpu) { | |
567 | int node = cpu_to_node(cpu); | |
568 | struct page *page; | |
569 | ||
fbd98167 CL |
570 | page = alloc_pages_node(node, |
571 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
572 | 0); | |
1da177e4 LT |
573 | if (!page) |
574 | goto out_cleanup; | |
575 | per_cpu(cpu_profile_hits, cpu)[1] | |
576 | = (struct profile_hit *)page_address(page); | |
fbd98167 CL |
577 | page = alloc_pages_node(node, |
578 | GFP_KERNEL | __GFP_ZERO | GFP_THISNODE, | |
579 | 0); | |
1da177e4 LT |
580 | if (!page) |
581 | goto out_cleanup; | |
582 | per_cpu(cpu_profile_hits, cpu)[0] | |
583 | = (struct profile_hit *)page_address(page); | |
584 | } | |
585 | return 0; | |
586 | out_cleanup: | |
587 | prof_on = 0; | |
d59dd462 | 588 | smp_mb(); |
15c8b6c1 | 589 | on_each_cpu(profile_nop, NULL, 1); |
1da177e4 LT |
590 | for_each_online_cpu(cpu) { |
591 | struct page *page; | |
592 | ||
593 | if (per_cpu(cpu_profile_hits, cpu)[0]) { | |
594 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); | |
595 | per_cpu(cpu_profile_hits, cpu)[0] = NULL; | |
596 | __free_page(page); | |
597 | } | |
598 | if (per_cpu(cpu_profile_hits, cpu)[1]) { | |
599 | page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); | |
600 | per_cpu(cpu_profile_hits, cpu)[1] = NULL; | |
601 | __free_page(page); | |
602 | } | |
603 | } | |
604 | return -1; | |
605 | } | |
606 | #else | |
607 | #define create_hash_tables() ({ 0; }) | |
608 | #endif | |
609 | ||
84196414 | 610 | int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */ |
1da177e4 LT |
611 | { |
612 | struct proc_dir_entry *entry; | |
613 | ||
614 | if (!prof_on) | |
615 | return 0; | |
616 | if (create_hash_tables()) | |
22b8ce94 | 617 | return -ENOMEM; |
c33fff0a DL |
618 | entry = proc_create("profile", S_IWUSR | S_IRUGO, |
619 | NULL, &proc_profile_operations); | |
1ad82fd5 | 620 | if (!entry) |
1da177e4 | 621 | return 0; |
1da177e4 LT |
622 | entry->size = (1+prof_len) * sizeof(atomic_t); |
623 | hotcpu_notifier(profile_cpu_callback, 0); | |
624 | return 0; | |
625 | } | |
626 | module_init(create_proc_profile); | |
627 | #endif /* CONFIG_PROC_FS */ |