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 | { |
9f029e83 | 33 | struct trace_array *tr = branch_tracer; |
52f232cb | 34 | struct ring_buffer_event *event; |
9f029e83 | 35 | struct trace_branch *entry; |
52f232cb SR |
36 | unsigned long flags, irq_flags; |
37 | int cpu, pc; | |
38 | const char *p; | |
39 | ||
40 | /* | |
41 | * I would love to save just the ftrace_likely_data pointer, but | |
42 | * this code can also be used by modules. Ugly things can happen | |
43 | * if the module is unloaded, and then we go and read the | |
44 | * pointer. This is slower, but much safer. | |
45 | */ | |
46 | ||
47 | if (unlikely(!tr)) | |
48 | return; | |
49 | ||
a5e25883 | 50 | local_irq_save(flags); |
52f232cb SR |
51 | cpu = raw_smp_processor_id(); |
52 | if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) | |
53 | goto out; | |
54 | ||
55 | event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), | |
56 | &irq_flags); | |
57 | if (!event) | |
58 | goto out; | |
59 | ||
60 | pc = preempt_count(); | |
61 | entry = ring_buffer_event_data(event); | |
62 | tracing_generic_entry_update(&entry->ent, flags, pc); | |
9f029e83 | 63 | entry->ent.type = TRACE_BRANCH; |
52f232cb SR |
64 | |
65 | /* Strip off the path, only save the file */ | |
66 | p = f->file + strlen(f->file); | |
67 | while (p >= f->file && *p != '/') | |
68 | p--; | |
69 | p++; | |
70 | ||
71 | strncpy(entry->func, f->func, TRACE_FUNC_SIZE); | |
72 | strncpy(entry->file, p, TRACE_FILE_SIZE); | |
73 | entry->func[TRACE_FUNC_SIZE] = 0; | |
74 | entry->file[TRACE_FILE_SIZE] = 0; | |
75 | entry->line = f->line; | |
76 | entry->correct = val == expect; | |
77 | ||
78 | ring_buffer_unlock_commit(tr->buffer, event, irq_flags); | |
79 | ||
80 | out: | |
81 | atomic_dec(&tr->data[cpu]->disabled); | |
a5e25883 | 82 | local_irq_restore(flags); |
52f232cb SR |
83 | } |
84 | ||
85 | static inline | |
9f029e83 | 86 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 87 | { |
9f029e83 | 88 | if (!branch_tracing_enabled) |
52f232cb SR |
89 | return; |
90 | ||
91 | probe_likely_condition(f, val, expect); | |
92 | } | |
93 | ||
9f029e83 | 94 | int enable_branch_tracing(struct trace_array *tr) |
52f232cb SR |
95 | { |
96 | int ret = 0; | |
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 SR |
107 | |
108 | return ret; | |
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 | { |
f04109bf | 136 | tracing_reset_online_cpus(tr); |
80e5ea45 | 137 | start_branch_trace(tr); |
1c80025a | 138 | return 0; |
80e5ea45 SR |
139 | } |
140 | ||
141 | static void branch_trace_reset(struct trace_array *tr) | |
142 | { | |
143 | stop_branch_trace(tr); | |
144 | } | |
145 | ||
f633cef0 SR |
146 | static int |
147 | trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags) | |
148 | { | |
149 | struct print_entry *field; | |
150 | ||
151 | trace_assign_type(field, entry); | |
152 | ||
153 | if (seq_print_ip_sym(s, field->ip, flags)) | |
154 | goto partial; | |
155 | ||
156 | if (trace_seq_printf(s, ": %s", field->buf)) | |
157 | goto partial; | |
158 | ||
159 | partial: | |
160 | return TRACE_TYPE_PARTIAL_LINE; | |
161 | } | |
162 | ||
2c9b238e | 163 | static int trace_branch_print(struct trace_iterator *iter, int flags) |
f633cef0 SR |
164 | { |
165 | struct trace_branch *field; | |
166 | ||
2c9b238e | 167 | trace_assign_type(field, iter->ent); |
f633cef0 | 168 | |
2c9b238e | 169 | if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n", |
f633cef0 SR |
170 | field->correct ? " ok " : " MISS ", |
171 | field->func, | |
172 | field->file, | |
173 | field->line)) | |
174 | return TRACE_TYPE_PARTIAL_LINE; | |
175 | ||
d9793bd8 | 176 | return TRACE_TYPE_HANDLED; |
f633cef0 SR |
177 | } |
178 | ||
e302cf3f | 179 | |
f633cef0 SR |
180 | static struct trace_event trace_branch_event = { |
181 | .type = TRACE_BRANCH, | |
182 | .trace = trace_branch_print, | |
183 | .latency_trace = trace_branch_print, | |
184 | .raw = trace_nop_print, | |
185 | .hex = trace_nop_print, | |
186 | .binary = trace_nop_print, | |
187 | }; | |
188 | ||
002bb86d FW |
189 | static struct tracer branch_trace __read_mostly = |
190 | { | |
191 | .name = "branch", | |
192 | .init = branch_trace_init, | |
193 | .reset = branch_trace_reset, | |
194 | #ifdef CONFIG_FTRACE_SELFTEST | |
195 | .selftest = trace_selftest_startup_branch, | |
196 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
197 | }; | |
198 | ||
199 | __init static int init_branch_tracer(void) | |
200 | { | |
201 | int ret; | |
202 | ||
203 | ret = register_ftrace_event(&trace_branch_event); | |
204 | if (!ret) { | |
205 | printk(KERN_WARNING "Warning: could not register " | |
206 | "branch events\n"); | |
207 | return 1; | |
208 | } | |
209 | return register_tracer(&branch_trace); | |
210 | } | |
211 | device_initcall(init_branch_tracer); | |
212 | ||
52f232cb SR |
213 | #else |
214 | static inline | |
9f029e83 | 215 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
216 | { |
217 | } | |
2ed84eeb | 218 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 219 | |
9f029e83 | 220 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 221 | { |
52f232cb SR |
222 | /* |
223 | * I would love to have a trace point here instead, but the | |
224 | * trace point code is so inundated with unlikely and likely | |
225 | * conditions that the recursive nightmare that exists is too | |
226 | * much to try to get working. At least for now. | |
227 | */ | |
228 | trace_likely_condition(f, val, expect); | |
229 | ||
1f0d69a9 SR |
230 | /* FIXME: Make this atomic! */ |
231 | if (val == expect) | |
232 | f->correct++; | |
233 | else | |
234 | f->incorrect++; | |
235 | } | |
236 | EXPORT_SYMBOL(ftrace_likely_update); | |
237 | ||
e302cf3f FW |
238 | extern unsigned long __start_annotated_branch_profile[]; |
239 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 240 | |
e302cf3f | 241 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 242 | { |
e302cf3f FW |
243 | seq_printf(m, " correct incorrect %% "); |
244 | seq_printf(m, " Function " | |
245 | " File Line\n" | |
246 | " ------- --------- - " | |
247 | " -------- " | |
248 | " ---- ----\n"); | |
249 | return 0; | |
1f0d69a9 SR |
250 | } |
251 | ||
e302cf3f | 252 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 253 | { |
e302cf3f | 254 | long percent; |
1f0d69a9 | 255 | |
e302cf3f FW |
256 | if (p->correct) { |
257 | percent = p->incorrect * 100; | |
258 | percent /= p->correct + p->incorrect; | |
259 | } else | |
260 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 261 | |
e302cf3f | 262 | return percent; |
1f0d69a9 SR |
263 | } |
264 | ||
e302cf3f | 265 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 266 | { |
9f029e83 | 267 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 268 | const char *f; |
bac28bfe | 269 | long percent; |
1f0d69a9 | 270 | |
1f0d69a9 SR |
271 | /* Only print the file, not the path */ |
272 | f = p->file + strlen(p->file); | |
273 | while (f >= p->file && *f != '/') | |
274 | f--; | |
275 | f++; | |
276 | ||
2bcd521a SR |
277 | /* |
278 | * The miss is overlayed on correct, and hit on incorrect. | |
279 | */ | |
e302cf3f | 280 | percent = get_incorrect_percent(p); |
1f0d69a9 | 281 | |
bac28bfe SR |
282 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
283 | if (percent < 0) | |
284 | seq_printf(m, " X "); | |
285 | else | |
286 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
287 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
288 | return 0; | |
289 | } | |
290 | ||
e302cf3f FW |
291 | static void *annotated_branch_stat_start(void) |
292 | { | |
293 | return __start_annotated_branch_profile; | |
294 | } | |
1f0d69a9 | 295 | |
e302cf3f FW |
296 | static void * |
297 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 298 | { |
e302cf3f | 299 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 300 | |
e302cf3f | 301 | ++p; |
1f0d69a9 | 302 | |
e302cf3f FW |
303 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
304 | return NULL; | |
305 | ||
306 | return p; | |
1f0d69a9 SR |
307 | } |
308 | ||
e302cf3f FW |
309 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
310 | { | |
311 | struct ftrace_branch_data *a = p1; | |
312 | struct ftrace_branch_data *b = p2; | |
313 | ||
314 | long percent_a, percent_b; | |
315 | ||
316 | percent_a = get_incorrect_percent(a); | |
317 | percent_b = get_incorrect_percent(b); | |
318 | ||
319 | if (percent_a < percent_b) | |
320 | return -1; | |
321 | if (percent_a > percent_b) | |
322 | return 1; | |
323 | else | |
324 | return 0; | |
325 | } | |
1f0d69a9 | 326 | |
002bb86d FW |
327 | static struct tracer_stat annotated_branch_stats = { |
328 | .name = "branch_annotated", | |
329 | .stat_start = annotated_branch_stat_start, | |
330 | .stat_next = annotated_branch_stat_next, | |
331 | .stat_cmp = annotated_branch_stat_cmp, | |
332 | .stat_headers = annotated_branch_stat_headers, | |
333 | .stat_show = branch_stat_show | |
334 | }; | |
335 | ||
336 | __init static int init_annotated_branch_stats(void) | |
337 | { | |
338 | int ret; | |
339 | ||
340 | ret = register_stat_tracer(&annotated_branch_stats); | |
341 | if (!ret) { | |
342 | printk(KERN_WARNING "Warning: could not register " | |
343 | "annotated branches stats\n"); | |
344 | return 1; | |
345 | } | |
346 | return 0; | |
347 | } | |
348 | fs_initcall(init_annotated_branch_stats); | |
349 | ||
2bcd521a | 350 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 351 | |
e302cf3f FW |
352 | extern unsigned long __start_branch_profile[]; |
353 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 354 | |
e302cf3f FW |
355 | static int all_branch_stat_headers(struct seq_file *m) |
356 | { | |
357 | seq_printf(m, " miss hit %% "); | |
358 | seq_printf(m, " Function " | |
359 | " File Line\n" | |
360 | " ------- --------- - " | |
361 | " -------- " | |
362 | " ---- ----\n"); | |
363 | return 0; | |
364 | } | |
1f0d69a9 | 365 | |
e302cf3f | 366 | static void *all_branch_stat_start(void) |
1f0d69a9 | 367 | { |
e302cf3f FW |
368 | return __start_branch_profile; |
369 | } | |
370 | ||
371 | static void * | |
372 | all_branch_stat_next(void *v, int idx) | |
373 | { | |
374 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 375 | |
e302cf3f | 376 | ++p; |
1f0d69a9 | 377 | |
e302cf3f FW |
378 | if ((void *)p >= (void *)__stop_branch_profile) |
379 | return NULL; | |
1f0d69a9 | 380 | |
e302cf3f FW |
381 | return p; |
382 | } | |
2bcd521a | 383 | |
002bb86d FW |
384 | static struct tracer_stat all_branch_stats = { |
385 | .name = "branch_all", | |
034939b6 FW |
386 | .stat_start = all_branch_stat_start, |
387 | .stat_next = all_branch_stat_next, | |
388 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 389 | .stat_show = branch_stat_show |
034939b6 | 390 | }; |
e302cf3f | 391 | |
002bb86d | 392 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 393 | { |
e302cf3f | 394 | int ret; |
002bb86d FW |
395 | |
396 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 397 | if (!ret) { |
002bb86d FW |
398 | printk(KERN_WARNING "Warning: could not register " |
399 | "all branches stats\n"); | |
e302cf3f FW |
400 | return 1; |
401 | } | |
002bb86d | 402 | return 0; |
e302cf3f | 403 | } |
002bb86d FW |
404 | fs_initcall(all_annotated_branch_stats); |
405 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |