Commit | Line | Data |
---|---|---|
1c25284c MD |
1 | /* |
2 | * LTT ascii binary buffer to ascii converter. | |
3 | * | |
4 | * Copyright 2008 - 2009 Lai Jiangshan (laijs@cn.fujitsu.com) | |
5 | * Copyright 2009 - Mathieu Desnoyers mathieu.desnoyers@polymtl.ca | |
6 | * | |
7 | * Dual LGPL v2.1/GPL v2 license. | |
8 | */ | |
9 | ||
10 | /* | |
11 | * TODO | |
12 | * | |
13 | * Move to new switch behavior: Wait for data for the duration of the | |
14 | * timer interval + safety, if none is coming, consider that no activity occured | |
15 | * in the buffer. | |
16 | * | |
17 | * Fix case when having a text file open and destroying trace. | |
18 | * | |
19 | * - Automate periodical switch: | |
20 | * | |
21 | * The debugfs file "switch_timer" receives a timer period as parameter | |
22 | * (e.g. echo 100 > switch_timer) to activate the timer per channel. This can | |
23 | * also be accessed through the internal API _before the trace session starts_. | |
24 | * This timer will insure that we periodically have subbuffers to read, and | |
25 | * therefore that the merge-sort does not wait endlessly for a subbuffer. | |
26 | * | |
27 | * - If a channel is switched and read without data, make sure it is still | |
28 | * considered afterward (not removed from the queue). | |
29 | * | |
30 | * - Create a ascii/tracename/ALL file to merge-sort all active channels. | |
31 | * - Create a ascii/tracename/README file to contain the text output legend. | |
32 | * - Remove leading zeroes from timestamps. | |
33 | * - Enhance pretty-printing to make sure all types used for addesses output in | |
34 | * the form 0xAB00000000 (not decimal). This is true for %p and 0x%...X. | |
35 | * - Hotplug support | |
36 | */ | |
37 | ||
38 | ||
39 | ||
40 | ||
41 | #include <linux/module.h> | |
42 | #include <linux/seq_file.h> | |
43 | #include <linux/debugfs.h> | |
44 | #include <linux/module.h> | |
45 | #include <linux/string.h> | |
46 | #include <linux/delay.h> | |
47 | #include <linux/slab.h> | |
48 | #include <linux/cpu.h> | |
49 | #include <linux/fs.h> | |
50 | ||
51 | #include "ltt-tracer.h" | |
52 | #include "ltt-relay.h" | |
53 | #include "ltt-relay-lockless.h" | |
54 | ||
55 | #if 0 | |
56 | #define DEBUGP printk | |
57 | #else | |
58 | #define DEBUGP(fmt , a...) | |
59 | #endif | |
60 | ||
61 | struct dentry *ltt_ascii_dir_dentry; | |
62 | EXPORT_SYMBOL_GPL(ltt_ascii_dir_dentry); | |
63 | ||
64 | struct ltt_relay_iter; | |
65 | ||
66 | struct ltt_relay_cpu_iter { | |
67 | /* cpu buffer information */ | |
68 | struct ltt_chanbuf *buf; | |
69 | struct ltt_relay_iter *iter; | |
70 | int sb_ref; /* holding a reference to a subbuffer */ | |
71 | long read_sb_offset; /* offset of the subbuffer read */ | |
72 | ||
73 | /* current event information */ | |
74 | struct ltt_subbuffer_header *header; | |
75 | long hdr_offset; /* event header offset */ | |
76 | long payload_offset; /* event payload offset */ | |
77 | u64 tsc; /* full 64-bits timestamp value */ | |
78 | u32 data_size; | |
79 | u16 chID; /* channel ID, const */ | |
80 | u16 eID; | |
81 | }; | |
82 | ||
83 | struct ltt_relay_iter { | |
84 | struct ltt_relay_cpu_iter iter_cpu[NR_CPUS]; | |
85 | struct ltt_chan *chan; | |
86 | loff_t pos; | |
87 | int cpu; | |
88 | int nr_refs; | |
89 | }; | |
90 | ||
91 | /* | |
92 | * offset of 0 in subbuffer means "subbuf size" (filled subbuffer). | |
93 | */ | |
94 | static int is_subbuffer_offset_end(struct ltt_relay_cpu_iter *citer, | |
95 | long offset) | |
96 | { | |
97 | struct ltt_chan *chan = container_of(citer->buf->a.chan, | |
98 | struct ltt_chan, a); | |
99 | long sub_offset = SUBBUF_OFFSET(offset - 1, chan) + 1; | |
100 | ||
101 | return (sub_offset <= citer->header->data_size); | |
102 | } | |
103 | ||
104 | static u64 calculate_tsc(u64 pre_tsc, u64 read_tsc, unsigned int rflags) | |
105 | { | |
106 | u64 new_tsc = read_tsc; | |
107 | ||
108 | if (rflags != LTT_RFLAG_ID_SIZE_TSC) { | |
109 | BUG_ON(read_tsc >> LTT_TSC_BITS); | |
110 | ||
111 | new_tsc = (pre_tsc & ~LTT_TSC_MASK) + read_tsc; | |
112 | if (read_tsc < (pre_tsc & LTT_TSC_MASK)) | |
113 | new_tsc += 1UL << LTT_TSC_BITS; | |
114 | } | |
115 | ||
116 | return new_tsc; | |
117 | } | |
118 | ||
119 | /* | |
120 | * calculate payload offset */ | |
121 | static inline long calculate_payload_offset(long offset, u16 chID, u16 eID) | |
122 | { | |
123 | const char *fmt; | |
124 | ||
125 | if (!ltt_get_alignment()) | |
126 | return offset; | |
127 | ||
128 | fmt = marker_get_fmt_from_id(chID, eID); | |
129 | BUG_ON(!fmt); | |
130 | ||
131 | return offset + ltt_fmt_largest_align(offset, fmt); | |
132 | } | |
133 | ||
134 | static void update_new_event(struct ltt_relay_cpu_iter *citer, long hdr_offset) | |
135 | { | |
136 | u64 read_tsc; | |
137 | unsigned int rflags; | |
138 | long tmp_offset; | |
139 | ||
140 | WARN_ON_ONCE(hdr_offset != citer->hdr_offset); | |
141 | ||
142 | tmp_offset = ltt_read_event_header(&citer->buf->a, hdr_offset, | |
143 | &read_tsc, &citer->data_size, | |
144 | &citer->eID, &rflags); | |
145 | citer->payload_offset = calculate_payload_offset(tmp_offset, | |
146 | citer->chID, | |
147 | citer->eID); | |
148 | ||
149 | citer->tsc = calculate_tsc(citer->tsc, read_tsc, rflags); | |
150 | } | |
151 | ||
152 | static void update_event_size(struct ltt_relay_cpu_iter *citer, long hdr_offset) | |
153 | { | |
154 | char output[1]; | |
155 | const char *fmt; | |
156 | size_t data_size; | |
157 | ||
158 | if (citer->data_size != INT_MAX) | |
159 | return; | |
160 | ||
161 | fmt = marker_get_fmt_from_id(citer->chID, citer->eID); | |
162 | BUG_ON(!fmt); | |
163 | ltt_serialize_printf(citer->buf, citer->payload_offset, | |
164 | &data_size, output, 0, fmt); | |
165 | citer->data_size = data_size; | |
166 | } | |
167 | ||
168 | static void update_cpu_iter(struct ltt_relay_cpu_iter *citer, long hdr_offset) | |
169 | { | |
170 | if (unlikely((!citer->sb_ref) | |
171 | || is_subbuffer_offset_end(citer, hdr_offset))) { | |
172 | citer->header = NULL; | |
173 | return; | |
174 | } | |
175 | update_new_event(citer, hdr_offset); | |
176 | update_event_size(citer, hdr_offset); | |
177 | } | |
178 | ||
179 | /* | |
180 | * returns 0 if we get a subbuffer reference. | |
181 | * else, the buffer has not available data, try again later. | |
182 | */ | |
183 | static int subbuffer_start(struct ltt_relay_cpu_iter *citer, long *offset) | |
184 | { | |
185 | int ret; | |
186 | struct ltt_relay_iter *iter = citer->iter; | |
187 | ||
188 | ret = ltt_chanbuf_get_subbuf(citer->buf, offset); | |
189 | if (!ret) { | |
190 | citer->header = ltt_relay_read_offset_address(&citer->buf->a, | |
191 | *offset); | |
192 | citer->hdr_offset = (*offset) + ltt_sb_header_size(); | |
193 | citer->tsc = citer->header->cycle_count_begin; | |
194 | iter->nr_refs++; | |
195 | citer->sb_ref = 1; | |
196 | return 0; | |
197 | } else { | |
198 | if (ltt_chanbuf_is_finalized(citer->buf)) | |
199 | return -ENODATA; | |
200 | else | |
201 | return -EAGAIN; | |
202 | } | |
203 | } | |
204 | ||
205 | static void subbuffer_stop(struct ltt_relay_cpu_iter *citer, | |
206 | long offset) | |
207 | { | |
208 | int ret; | |
209 | struct ltt_relay_iter *iter = citer->iter; | |
210 | ||
211 | WARN_ON_ONCE(!citer->sb_ref); | |
212 | ret = ltt_chanbuf_put_subbuf(citer->buf, offset); | |
213 | WARN_ON_ONCE(ret); | |
214 | citer->sb_ref = 0; | |
215 | iter->nr_refs--; | |
216 | } | |
217 | ||
218 | static void ltt_relay_advance_cpu_iter(struct ltt_relay_cpu_iter *citer) | |
219 | { | |
220 | long old_offset = citer->payload_offset; | |
221 | long new_offset = citer->payload_offset; | |
222 | int ret; | |
223 | ||
224 | /* find that whether we read all data in this subbuffer */ | |
225 | if (unlikely(is_subbuffer_offset_end(citer, | |
226 | old_offset + citer->data_size))) { | |
227 | DEBUGP(KERN_DEBUG "LTT ASCII stop cpu %d offset %lX\n", | |
228 | citer->buf->a.cpu, citer->read_sb_offset); | |
229 | subbuffer_stop(citer, citer->read_sb_offset); | |
230 | for (;;) { | |
231 | ret = subbuffer_start(citer, &citer->read_sb_offset); | |
232 | DEBUGP(KERN_DEBUG | |
233 | "LTT ASCII start cpu %d ret %d offset %lX\n", | |
234 | citer->buf->a.cpu, ret, citer->read_sb_offset); | |
235 | if (!ret || ret == -ENODATA) { | |
236 | break; /* got data, or finalized */ | |
237 | } else { /* -EAGAIN */ | |
238 | if (signal_pending(current)) | |
239 | break; | |
240 | schedule_timeout_interruptible(1); | |
241 | //TODO: check for no-data delay. take ref. break | |
242 | } | |
243 | } | |
244 | } else { | |
245 | new_offset += citer->data_size; | |
246 | citer->hdr_offset = new_offset + ltt_align(new_offset, sizeof(struct ltt_event_header)); | |
247 | DEBUGP(KERN_DEBUG | |
248 | "LTT ASCII old_offset %lX new_offset %lX cpu %d\n", | |
249 | old_offset, new_offset, citer->buf->a.cpu); | |
250 | } | |
251 | ||
252 | update_cpu_iter(citer, citer->hdr_offset); | |
253 | } | |
254 | ||
255 | static int cpu_iter_eof(struct ltt_relay_cpu_iter *citer) | |
256 | { | |
257 | return !citer->sb_ref; | |
258 | } | |
259 | ||
260 | static int ltt_relay_iter_eof(struct ltt_relay_iter *iter) | |
261 | { | |
262 | return iter->nr_refs == 0; | |
263 | } | |
264 | ||
265 | static void ltt_relay_advance_iter(struct ltt_relay_iter *iter) | |
266 | { | |
267 | int i; | |
268 | struct ltt_relay_cpu_iter *curr, *min = NULL; | |
269 | iter->cpu = -1; | |
270 | ||
271 | /* | |
272 | * find the event with the minimum tsc. | |
273 | * TODO: use min-heep for 4096CPUS | |
274 | */ | |
275 | for_each_possible_cpu(i) { | |
276 | curr = &iter->iter_cpu[i]; | |
277 | ||
278 | if (!curr->buf->a.allocated || !curr->header) | |
279 | continue; | |
280 | ||
281 | if (cpu_iter_eof(curr)) | |
282 | continue; | |
283 | ||
284 | if (!min || curr->tsc < min->tsc) { | |
285 | min = curr; | |
286 | iter->cpu = i; | |
287 | } | |
288 | } | |
289 | ||
290 | /* update cpu_iter for next ltt_relay_advance_iter() */ | |
291 | if (min) | |
292 | ltt_relay_advance_cpu_iter(min); | |
293 | } | |
294 | ||
295 | static void *ascii_next(struct seq_file *m, void *v, loff_t *ppos) | |
296 | { | |
297 | struct ltt_relay_iter *iter = m->private; | |
298 | ||
299 | WARN_ON_ONCE(!iter->nr_refs); | |
300 | BUG_ON(v != iter); | |
301 | ||
302 | ltt_relay_advance_iter(iter); | |
303 | return (ltt_relay_iter_eof(iter) || signal_pending(current)) | |
304 | ? NULL : iter; | |
305 | } | |
306 | ||
307 | static void *ascii_start(struct seq_file *m, loff_t *ppos) | |
308 | { | |
309 | struct ltt_relay_iter *iter = m->private; | |
310 | ||
311 | ltt_relay_advance_iter(iter); | |
312 | return (ltt_relay_iter_eof(iter) || signal_pending(current)) | |
313 | ? NULL : iter; | |
314 | } | |
315 | ||
316 | static void ascii_stop(struct seq_file *m, void *v) | |
317 | { | |
318 | } | |
319 | ||
320 | static | |
321 | int seq_serialize(struct seq_file *m, struct ltt_chanbuf *buf, | |
322 | size_t buf_offset, const char *fmt, size_t *data_size) | |
323 | { | |
324 | int len; | |
325 | ||
326 | if (m->count < m->size) { | |
327 | len = ltt_serialize_printf(buf, buf_offset, data_size, | |
328 | m->buf + m->count, | |
329 | m->size - m->count, fmt); | |
330 | if (m->count + len < m->size) { | |
331 | m->count += len; | |
332 | return 0; | |
333 | } | |
334 | } | |
335 | ||
336 | m->count = m->size; | |
337 | return -1; | |
338 | } | |
339 | ||
340 | static int ascii_show(struct seq_file *m, void *v) | |
341 | { | |
342 | struct ltt_relay_iter *iter = v; | |
343 | struct ltt_relay_cpu_iter *citer; | |
344 | const char *name; | |
345 | const char *fmt; | |
346 | unsigned long long tsc; | |
347 | size_t data_size; | |
348 | ||
349 | if (iter->cpu == -1) | |
350 | return 0; | |
351 | ||
352 | citer = &iter->iter_cpu[iter->cpu]; | |
353 | WARN_ON_ONCE(!citer->sb_ref); | |
354 | /* | |
355 | * Nothing to show, we are at the end of the last subbuffer currently | |
356 | * having data. | |
357 | */ | |
358 | if (!citer->header) | |
359 | return 0; | |
360 | ||
361 | tsc = citer->tsc; | |
362 | name = marker_get_name_from_id(citer->chID, citer->eID); | |
363 | fmt = marker_get_fmt_from_id(citer->chID, citer->eID); | |
364 | ||
365 | if (!name || !fmt) | |
366 | return 0; | |
367 | ||
368 | seq_printf(m, "event:%16.16s: cpu:%2d time:%20.20llu ", | |
369 | name, iter->cpu, tsc); | |
370 | seq_serialize(m, citer->buf, citer->payload_offset, fmt, &data_size); | |
371 | seq_puts(m, "\n"); | |
372 | if (citer->data_size == INT_MAX) | |
373 | citer->data_size = data_size; | |
374 | ||
375 | return 0; | |
376 | } | |
377 | ||
378 | static struct seq_operations ascii_seq_ops = { | |
379 | .start = ascii_start, | |
380 | .next = ascii_next, | |
381 | .stop = ascii_stop, | |
382 | .show = ascii_show, | |
383 | }; | |
384 | ||
385 | /* FIXME : cpu hotplug support */ | |
386 | static int ltt_relay_iter_open_channel(struct ltt_relay_iter *iter, | |
387 | struct ltt_chan *chan) | |
388 | { | |
389 | int i, ret; | |
390 | u16 chID = ltt_channels_get_index_from_name(chan->a.filename); | |
391 | ||
392 | /* we don't need lock relay_channels_mutex */ | |
393 | for_each_possible_cpu(i) { | |
394 | struct ltt_relay_cpu_iter *citer = &iter->iter_cpu[i]; | |
395 | ||
396 | citer->buf = per_cpu_ptr(chan->a.buf, i); | |
397 | if (!citer->buf->a.allocated) | |
398 | continue; | |
399 | ||
400 | citer->iter = iter; /* easy lazy parent info */ | |
401 | citer->chID = chID; | |
402 | ||
403 | ret = ltt_chanbuf_open_read(citer->buf); | |
404 | if (ret) { | |
405 | /* Failed to open a percpu buffer, close everything. */ | |
406 | citer->buf = NULL; | |
407 | goto error; | |
408 | } | |
409 | ||
410 | for (;;) { | |
411 | ret = subbuffer_start(citer, | |
412 | &citer->read_sb_offset); | |
413 | DEBUGP(KERN_DEBUG | |
414 | "LTT ASCII open start " | |
415 | "cpu %d ret %d offset %lX\n", | |
416 | citer->buf->a.cpu, ret, citer->read_sb_offset); | |
417 | if (!ret || ret == -ENODATA) { | |
418 | break; /* got data, or finalized */ | |
419 | } else { /* -EAGAIN */ | |
420 | if (signal_pending(current)) | |
421 | break; | |
422 | schedule_timeout_interruptible(1); | |
423 | } | |
424 | } | |
425 | update_cpu_iter(citer, citer->hdr_offset); | |
426 | } | |
427 | if (!iter->nr_refs) { | |
428 | ret = -ENODATA; | |
429 | goto error; | |
430 | } | |
431 | ||
432 | return 0; | |
433 | ||
434 | error: | |
435 | for_each_possible_cpu(i) { | |
436 | struct ltt_relay_cpu_iter *citer = &iter->iter_cpu[i]; | |
437 | ||
438 | if (!citer->buf) | |
439 | break; | |
440 | ||
441 | if (citer->buf->a.allocated) | |
442 | ltt_chanbuf_release_read(citer->buf); | |
443 | } | |
444 | return ret; | |
445 | } | |
446 | ||
447 | /* FIXME : cpu hotplug support */ | |
448 | static int ltt_relay_iter_release_channel(struct ltt_relay_iter *iter) | |
449 | { | |
450 | int i; | |
451 | ||
452 | for_each_possible_cpu(i) { | |
453 | struct ltt_relay_cpu_iter *citer = &iter->iter_cpu[i]; | |
454 | ||
455 | if (citer->sb_ref) { | |
456 | WARN_ON_ONCE(!citer->buf->a.allocated); | |
457 | DEBUGP(KERN_DEBUG | |
458 | "LTT ASCII release stop cpu %d offset %lX\n", | |
459 | citer->buf->a.cpu, citer->read_sb_offset); | |
460 | subbuffer_stop(&iter->iter_cpu[i], | |
461 | citer->read_sb_offset); | |
462 | } | |
463 | if (citer->buf->a.allocated) | |
464 | ltt_chanbuf_release_read(citer->buf); | |
465 | } | |
466 | WARN_ON_ONCE(iter->nr_refs); | |
467 | return 0; | |
468 | } | |
469 | ||
470 | static int ltt_relay_ascii_open(struct inode *inode, struct file *file) | |
471 | { | |
472 | int ret; | |
473 | struct ltt_chan *chan = inode->i_private; | |
474 | struct ltt_relay_iter *iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
475 | if (!iter) | |
476 | return -ENOMEM; | |
477 | ||
478 | iter->chan = chan; | |
479 | ret = ltt_relay_iter_open_channel(iter, chan); | |
480 | if (ret) | |
481 | goto error_free_alloc; | |
482 | ||
483 | ret = seq_open(file, &ascii_seq_ops); | |
484 | if (ret) | |
485 | goto error_release_channel; | |
486 | ((struct seq_file *)file->private_data)->private = iter; | |
487 | return 0; | |
488 | ||
489 | error_release_channel: | |
490 | ltt_relay_iter_release_channel(iter); | |
491 | error_free_alloc: | |
492 | kfree(iter); | |
493 | return ret; | |
494 | } | |
495 | ||
496 | static int ltt_relay_ascii_release(struct inode *inode, struct file *file) | |
497 | { | |
498 | struct seq_file *seq = file->private_data; | |
499 | struct ltt_relay_iter *iter = seq->private; | |
500 | ||
501 | ltt_relay_iter_release_channel(iter); | |
502 | kfree(iter); | |
503 | return 0; | |
504 | } | |
505 | ||
506 | static struct file_operations ltt_ascii_fops = | |
507 | { | |
508 | .read = seq_read, | |
509 | .open = ltt_relay_ascii_open, | |
510 | .release = ltt_relay_ascii_release, | |
511 | .llseek = no_llseek, | |
512 | .owner = THIS_MODULE, | |
513 | }; | |
514 | ||
515 | int ltt_ascii_create(struct ltt_chan *chan) | |
516 | { | |
517 | struct dentry *dentry; | |
518 | ||
519 | dentry = debugfs_create_file(chan->a.filename, | |
520 | S_IRUSR | S_IRGRP, | |
521 | chan->a.trace->dentry.ascii_root, | |
522 | chan, <t_ascii_fops); | |
523 | if (IS_ERR(dentry)) | |
524 | return PTR_ERR(dentry); | |
525 | ||
526 | if (!dentry) | |
527 | return -EEXIST; | |
528 | ||
529 | chan->a.ascii_dentry = dentry; | |
530 | dentry->d_inode->i_private = chan; | |
531 | return 0; | |
532 | } | |
533 | EXPORT_SYMBOL_GPL(ltt_ascii_create); | |
534 | ||
535 | void ltt_ascii_remove(struct ltt_chan *chan) | |
536 | { | |
537 | struct dentry *dentry; | |
538 | ||
539 | dentry = dget(chan->a.ascii_dentry); | |
540 | debugfs_remove(dentry); | |
541 | /* TODO: wait / wakeup instead */ | |
542 | /* | |
543 | * Wait for every reference to the dentry to be gone, | |
544 | * except us. | |
545 | */ | |
546 | while (atomic_read(&dentry->d_count) != 1) | |
547 | msleep(100); | |
548 | dput(dentry); | |
549 | } | |
550 | EXPORT_SYMBOL_GPL(ltt_ascii_remove); | |
551 | ||
552 | int ltt_ascii_create_dir(struct ltt_trace *new_trace) | |
553 | { | |
554 | new_trace->dentry.ascii_root = debugfs_create_dir(new_trace->trace_name, | |
555 | ltt_ascii_dir_dentry); | |
556 | if (!new_trace->dentry.ascii_root) | |
557 | return -EEXIST; | |
558 | return 0; | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(ltt_ascii_create_dir); | |
561 | ||
562 | void ltt_ascii_remove_dir(struct ltt_trace *trace) | |
563 | { | |
564 | debugfs_remove(trace->dentry.ascii_root); | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(ltt_ascii_remove_dir); | |
567 | ||
568 | __init int ltt_ascii_init(void) | |
569 | { | |
570 | ltt_ascii_dir_dentry = debugfs_create_dir(LTT_ASCII, get_ltt_root()); | |
571 | ||
572 | return ltt_ascii_dir_dentry ? 0 : -EFAULT; | |
573 | } | |
574 | ||
575 | __exit void ltt_ascii_exit(void) | |
576 | { | |
577 | debugfs_remove(ltt_ascii_dir_dentry); | |
578 | put_ltt_root(); | |
579 | } | |
580 | ||
581 | MODULE_LICENSE("GPL and additional rights"); | |
582 | MODULE_AUTHOR("Lai Jiangshan@FNST and Mathieu Desnoyers"); | |
583 | MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Ascii Converter"); |