Commit | Line | Data |
---|---|---|
1f0d69a9 SR |
1 | /* |
2 | * unlikely profiler | |
3 | * | |
4 | * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com> | |
5 | */ | |
6 | #include <linux/kallsyms.h> | |
7 | #include <linux/seq_file.h> | |
8 | #include <linux/spinlock.h> | |
65c6dc6a | 9 | #include <linux/irqflags.h> |
1f0d69a9 SR |
10 | #include <linux/debugfs.h> |
11 | #include <linux/uaccess.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/ftrace.h> | |
14 | #include <linux/hash.h> | |
15 | #include <linux/fs.h> | |
16 | #include <asm/local.h> | |
f633cef0 | 17 | |
1f0d69a9 | 18 | #include "trace.h" |
002bb86d | 19 | #include "trace_stat.h" |
f633cef0 | 20 | #include "trace_output.h" |
1f0d69a9 | 21 | |
2ed84eeb | 22 | #ifdef CONFIG_BRANCH_TRACER |
52f232cb | 23 | |
002bb86d | 24 | static struct tracer branch_trace; |
9f029e83 SR |
25 | static int branch_tracing_enabled __read_mostly; |
26 | static DEFINE_MUTEX(branch_tracing_mutex); | |
e302cf3f | 27 | |
9f029e83 | 28 | static struct trace_array *branch_tracer; |
52f232cb SR |
29 | |
30 | static void | |
9f029e83 | 31 | probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 32 | { |
e1112b4d | 33 | struct ftrace_event_call *call = &event_branch; |
9f029e83 | 34 | struct trace_array *tr = branch_tracer; |
52f232cb | 35 | struct ring_buffer_event *event; |
9f029e83 | 36 | struct trace_branch *entry; |
8f6e8a31 | 37 | struct ring_buffer *buffer; |
0a987751 | 38 | unsigned long flags; |
52f232cb SR |
39 | int cpu, pc; |
40 | const char *p; | |
41 | ||
42 | /* | |
43 | * I would love to save just the ftrace_likely_data pointer, but | |
44 | * this code can also be used by modules. Ugly things can happen | |
45 | * if the module is unloaded, and then we go and read the | |
46 | * pointer. This is slower, but much safer. | |
47 | */ | |
48 | ||
49 | if (unlikely(!tr)) | |
50 | return; | |
51 | ||
a5e25883 | 52 | local_irq_save(flags); |
52f232cb SR |
53 | cpu = raw_smp_processor_id(); |
54 | if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) | |
55 | goto out; | |
56 | ||
51a763dd | 57 | pc = preempt_count(); |
8f6e8a31 SR |
58 | buffer = tr->buffer; |
59 | event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH, | |
51a763dd | 60 | sizeof(*entry), flags, pc); |
52f232cb SR |
61 | if (!event) |
62 | goto out; | |
63 | ||
52f232cb | 64 | entry = ring_buffer_event_data(event); |
52f232cb SR |
65 | |
66 | /* Strip off the path, only save the file */ | |
67 | p = f->file + strlen(f->file); | |
68 | while (p >= f->file && *p != '/') | |
69 | p--; | |
70 | p++; | |
71 | ||
72 | strncpy(entry->func, f->func, TRACE_FUNC_SIZE); | |
73 | strncpy(entry->file, p, TRACE_FILE_SIZE); | |
74 | entry->func[TRACE_FUNC_SIZE] = 0; | |
75 | entry->file[TRACE_FILE_SIZE] = 0; | |
76 | entry->line = f->line; | |
77 | entry->correct = val == expect; | |
78 | ||
8f6e8a31 SR |
79 | if (!filter_check_discard(call, entry, buffer, event)) |
80 | ring_buffer_unlock_commit(buffer, event); | |
52f232cb SR |
81 | |
82 | out: | |
83 | atomic_dec(&tr->data[cpu]->disabled); | |
a5e25883 | 84 | local_irq_restore(flags); |
52f232cb SR |
85 | } |
86 | ||
87 | static inline | |
9f029e83 | 88 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 89 | { |
9f029e83 | 90 | if (!branch_tracing_enabled) |
52f232cb SR |
91 | return; |
92 | ||
93 | probe_likely_condition(f, val, expect); | |
94 | } | |
95 | ||
9f029e83 | 96 | int enable_branch_tracing(struct trace_array *tr) |
52f232cb | 97 | { |
9f029e83 SR |
98 | mutex_lock(&branch_tracing_mutex); |
99 | branch_tracer = tr; | |
52f232cb SR |
100 | /* |
101 | * Must be seen before enabling. The reader is a condition | |
102 | * where we do not need a matching rmb() | |
103 | */ | |
104 | smp_wmb(); | |
9f029e83 SR |
105 | branch_tracing_enabled++; |
106 | mutex_unlock(&branch_tracing_mutex); | |
52f232cb | 107 | |
f54fc98a | 108 | return 0; |
52f232cb SR |
109 | } |
110 | ||
9f029e83 | 111 | void disable_branch_tracing(void) |
52f232cb | 112 | { |
9f029e83 | 113 | mutex_lock(&branch_tracing_mutex); |
52f232cb | 114 | |
9f029e83 | 115 | if (!branch_tracing_enabled) |
52f232cb SR |
116 | goto out_unlock; |
117 | ||
9f029e83 | 118 | branch_tracing_enabled--; |
52f232cb SR |
119 | |
120 | out_unlock: | |
9f029e83 | 121 | mutex_unlock(&branch_tracing_mutex); |
52f232cb | 122 | } |
80e5ea45 SR |
123 | |
124 | static void start_branch_trace(struct trace_array *tr) | |
125 | { | |
126 | enable_branch_tracing(tr); | |
127 | } | |
128 | ||
129 | static void stop_branch_trace(struct trace_array *tr) | |
130 | { | |
131 | disable_branch_tracing(); | |
132 | } | |
133 | ||
1c80025a | 134 | static int branch_trace_init(struct trace_array *tr) |
80e5ea45 | 135 | { |
80e5ea45 | 136 | start_branch_trace(tr); |
1c80025a | 137 | return 0; |
80e5ea45 SR |
138 | } |
139 | ||
140 | static void branch_trace_reset(struct trace_array *tr) | |
141 | { | |
142 | stop_branch_trace(tr); | |
143 | } | |
144 | ||
ae7462b4 ACM |
145 | static enum print_line_t trace_branch_print(struct trace_iterator *iter, |
146 | int flags) | |
f633cef0 SR |
147 | { |
148 | struct trace_branch *field; | |
149 | ||
2c9b238e | 150 | trace_assign_type(field, iter->ent); |
f633cef0 | 151 | |
2c9b238e | 152 | if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n", |
f633cef0 SR |
153 | field->correct ? " ok " : " MISS ", |
154 | field->func, | |
155 | field->file, | |
156 | field->line)) | |
157 | return TRACE_TYPE_PARTIAL_LINE; | |
158 | ||
d9793bd8 | 159 | return TRACE_TYPE_HANDLED; |
f633cef0 SR |
160 | } |
161 | ||
557055be Z |
162 | static void branch_print_header(struct seq_file *s) |
163 | { | |
164 | seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT" | |
165 | " FUNC:FILE:LINE\n"); | |
166 | seq_puts(s, "# | | | | | " | |
167 | " |\n"); | |
168 | } | |
e302cf3f | 169 | |
f633cef0 | 170 | static struct trace_event trace_branch_event = { |
ef18012b | 171 | .type = TRACE_BRANCH, |
f633cef0 | 172 | .trace = trace_branch_print, |
f633cef0 SR |
173 | }; |
174 | ||
002bb86d FW |
175 | static struct tracer branch_trace __read_mostly = |
176 | { | |
177 | .name = "branch", | |
178 | .init = branch_trace_init, | |
179 | .reset = branch_trace_reset, | |
180 | #ifdef CONFIG_FTRACE_SELFTEST | |
181 | .selftest = trace_selftest_startup_branch, | |
182 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
557055be | 183 | .print_header = branch_print_header, |
002bb86d FW |
184 | }; |
185 | ||
186 | __init static int init_branch_tracer(void) | |
187 | { | |
188 | int ret; | |
189 | ||
190 | ret = register_ftrace_event(&trace_branch_event); | |
191 | if (!ret) { | |
192 | printk(KERN_WARNING "Warning: could not register " | |
193 | "branch events\n"); | |
194 | return 1; | |
195 | } | |
196 | return register_tracer(&branch_trace); | |
197 | } | |
198 | device_initcall(init_branch_tracer); | |
199 | ||
52f232cb SR |
200 | #else |
201 | static inline | |
9f029e83 | 202 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
203 | { |
204 | } | |
2ed84eeb | 205 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 206 | |
9f029e83 | 207 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 208 | { |
52f232cb SR |
209 | /* |
210 | * I would love to have a trace point here instead, but the | |
211 | * trace point code is so inundated with unlikely and likely | |
212 | * conditions that the recursive nightmare that exists is too | |
213 | * much to try to get working. At least for now. | |
214 | */ | |
215 | trace_likely_condition(f, val, expect); | |
216 | ||
1f0d69a9 SR |
217 | /* FIXME: Make this atomic! */ |
218 | if (val == expect) | |
219 | f->correct++; | |
220 | else | |
221 | f->incorrect++; | |
222 | } | |
223 | EXPORT_SYMBOL(ftrace_likely_update); | |
224 | ||
e302cf3f FW |
225 | extern unsigned long __start_annotated_branch_profile[]; |
226 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 227 | |
e302cf3f | 228 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 229 | { |
e302cf3f FW |
230 | seq_printf(m, " correct incorrect %% "); |
231 | seq_printf(m, " Function " | |
232 | " File Line\n" | |
233 | " ------- --------- - " | |
234 | " -------- " | |
235 | " ---- ----\n"); | |
236 | return 0; | |
1f0d69a9 SR |
237 | } |
238 | ||
e302cf3f | 239 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 240 | { |
e302cf3f | 241 | long percent; |
1f0d69a9 | 242 | |
e302cf3f FW |
243 | if (p->correct) { |
244 | percent = p->incorrect * 100; | |
245 | percent /= p->correct + p->incorrect; | |
246 | } else | |
247 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 248 | |
e302cf3f | 249 | return percent; |
1f0d69a9 SR |
250 | } |
251 | ||
e302cf3f | 252 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 253 | { |
9f029e83 | 254 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 255 | const char *f; |
bac28bfe | 256 | long percent; |
1f0d69a9 | 257 | |
1f0d69a9 SR |
258 | /* Only print the file, not the path */ |
259 | f = p->file + strlen(p->file); | |
260 | while (f >= p->file && *f != '/') | |
261 | f--; | |
262 | f++; | |
263 | ||
2bcd521a SR |
264 | /* |
265 | * The miss is overlayed on correct, and hit on incorrect. | |
266 | */ | |
e302cf3f | 267 | percent = get_incorrect_percent(p); |
1f0d69a9 | 268 | |
bac28bfe SR |
269 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
270 | if (percent < 0) | |
271 | seq_printf(m, " X "); | |
272 | else | |
273 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
274 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
275 | return 0; | |
276 | } | |
277 | ||
42548008 | 278 | static void *annotated_branch_stat_start(struct tracer_stat *trace) |
e302cf3f FW |
279 | { |
280 | return __start_annotated_branch_profile; | |
281 | } | |
1f0d69a9 | 282 | |
e302cf3f FW |
283 | static void * |
284 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 285 | { |
e302cf3f | 286 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 287 | |
e302cf3f | 288 | ++p; |
1f0d69a9 | 289 | |
e302cf3f FW |
290 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
291 | return NULL; | |
292 | ||
293 | return p; | |
1f0d69a9 SR |
294 | } |
295 | ||
e302cf3f FW |
296 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
297 | { | |
298 | struct ftrace_branch_data *a = p1; | |
299 | struct ftrace_branch_data *b = p2; | |
300 | ||
301 | long percent_a, percent_b; | |
302 | ||
303 | percent_a = get_incorrect_percent(a); | |
304 | percent_b = get_incorrect_percent(b); | |
305 | ||
306 | if (percent_a < percent_b) | |
307 | return -1; | |
308 | if (percent_a > percent_b) | |
309 | return 1; | |
ede55c9d SR |
310 | |
311 | if (a->incorrect < b->incorrect) | |
312 | return -1; | |
313 | if (a->incorrect > b->incorrect) | |
314 | return 1; | |
315 | ||
316 | /* | |
317 | * Since the above shows worse (incorrect) cases | |
318 | * first, we continue that by showing best (correct) | |
319 | * cases last. | |
320 | */ | |
321 | if (a->correct > b->correct) | |
322 | return -1; | |
323 | if (a->correct < b->correct) | |
324 | return 1; | |
325 | ||
326 | return 0; | |
e302cf3f | 327 | } |
1f0d69a9 | 328 | |
002bb86d FW |
329 | static struct tracer_stat annotated_branch_stats = { |
330 | .name = "branch_annotated", | |
331 | .stat_start = annotated_branch_stat_start, | |
332 | .stat_next = annotated_branch_stat_next, | |
333 | .stat_cmp = annotated_branch_stat_cmp, | |
334 | .stat_headers = annotated_branch_stat_headers, | |
335 | .stat_show = branch_stat_show | |
336 | }; | |
337 | ||
338 | __init static int init_annotated_branch_stats(void) | |
339 | { | |
340 | int ret; | |
341 | ||
342 | ret = register_stat_tracer(&annotated_branch_stats); | |
343 | if (!ret) { | |
344 | printk(KERN_WARNING "Warning: could not register " | |
345 | "annotated branches stats\n"); | |
346 | return 1; | |
347 | } | |
348 | return 0; | |
349 | } | |
350 | fs_initcall(init_annotated_branch_stats); | |
351 | ||
2bcd521a | 352 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 353 | |
e302cf3f FW |
354 | extern unsigned long __start_branch_profile[]; |
355 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 356 | |
e302cf3f FW |
357 | static int all_branch_stat_headers(struct seq_file *m) |
358 | { | |
359 | seq_printf(m, " miss hit %% "); | |
360 | seq_printf(m, " Function " | |
361 | " File Line\n" | |
362 | " ------- --------- - " | |
363 | " -------- " | |
364 | " ---- ----\n"); | |
365 | return 0; | |
366 | } | |
1f0d69a9 | 367 | |
42548008 | 368 | static void *all_branch_stat_start(struct tracer_stat *trace) |
1f0d69a9 | 369 | { |
e302cf3f FW |
370 | return __start_branch_profile; |
371 | } | |
372 | ||
373 | static void * | |
374 | all_branch_stat_next(void *v, int idx) | |
375 | { | |
376 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 377 | |
e302cf3f | 378 | ++p; |
1f0d69a9 | 379 | |
e302cf3f FW |
380 | if ((void *)p >= (void *)__stop_branch_profile) |
381 | return NULL; | |
1f0d69a9 | 382 | |
e302cf3f FW |
383 | return p; |
384 | } | |
2bcd521a | 385 | |
002bb86d FW |
386 | static struct tracer_stat all_branch_stats = { |
387 | .name = "branch_all", | |
034939b6 FW |
388 | .stat_start = all_branch_stat_start, |
389 | .stat_next = all_branch_stat_next, | |
390 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 391 | .stat_show = branch_stat_show |
034939b6 | 392 | }; |
e302cf3f | 393 | |
002bb86d | 394 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 395 | { |
e302cf3f | 396 | int ret; |
002bb86d FW |
397 | |
398 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 399 | if (!ret) { |
002bb86d FW |
400 | printk(KERN_WARNING "Warning: could not register " |
401 | "all branches stats\n"); | |
e302cf3f FW |
402 | return 1; |
403 | } | |
002bb86d | 404 | return 0; |
e302cf3f | 405 | } |
002bb86d FW |
406 | fs_initcall(all_annotated_branch_stats); |
407 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |