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; |
0a987751 | 36 | unsigned long flags; |
52f232cb SR |
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 | ||
51a763dd ACM |
55 | pc = preempt_count(); |
56 | event = trace_buffer_lock_reserve(tr, TRACE_BRANCH, | |
57 | sizeof(*entry), flags, pc); | |
52f232cb SR |
58 | if (!event) |
59 | goto out; | |
60 | ||
52f232cb | 61 | entry = ring_buffer_event_data(event); |
52f232cb SR |
62 | |
63 | /* Strip off the path, only save the file */ | |
64 | p = f->file + strlen(f->file); | |
65 | while (p >= f->file && *p != '/') | |
66 | p--; | |
67 | p++; | |
68 | ||
69 | strncpy(entry->func, f->func, TRACE_FUNC_SIZE); | |
70 | strncpy(entry->file, p, TRACE_FILE_SIZE); | |
71 | entry->func[TRACE_FUNC_SIZE] = 0; | |
72 | entry->file[TRACE_FILE_SIZE] = 0; | |
73 | entry->line = f->line; | |
74 | entry->correct = val == expect; | |
75 | ||
0a987751 | 76 | ring_buffer_unlock_commit(tr->buffer, event); |
52f232cb SR |
77 | |
78 | out: | |
79 | atomic_dec(&tr->data[cpu]->disabled); | |
a5e25883 | 80 | local_irq_restore(flags); |
52f232cb SR |
81 | } |
82 | ||
83 | static inline | |
9f029e83 | 84 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 85 | { |
9f029e83 | 86 | if (!branch_tracing_enabled) |
52f232cb SR |
87 | return; |
88 | ||
89 | probe_likely_condition(f, val, expect); | |
90 | } | |
91 | ||
9f029e83 | 92 | int enable_branch_tracing(struct trace_array *tr) |
52f232cb | 93 | { |
9f029e83 SR |
94 | mutex_lock(&branch_tracing_mutex); |
95 | branch_tracer = tr; | |
52f232cb SR |
96 | /* |
97 | * Must be seen before enabling. The reader is a condition | |
98 | * where we do not need a matching rmb() | |
99 | */ | |
100 | smp_wmb(); | |
9f029e83 SR |
101 | branch_tracing_enabled++; |
102 | mutex_unlock(&branch_tracing_mutex); | |
52f232cb | 103 | |
f54fc98a | 104 | return 0; |
52f232cb SR |
105 | } |
106 | ||
9f029e83 | 107 | void disable_branch_tracing(void) |
52f232cb | 108 | { |
9f029e83 | 109 | mutex_lock(&branch_tracing_mutex); |
52f232cb | 110 | |
9f029e83 | 111 | if (!branch_tracing_enabled) |
52f232cb SR |
112 | goto out_unlock; |
113 | ||
9f029e83 | 114 | branch_tracing_enabled--; |
52f232cb SR |
115 | |
116 | out_unlock: | |
9f029e83 | 117 | mutex_unlock(&branch_tracing_mutex); |
52f232cb | 118 | } |
80e5ea45 SR |
119 | |
120 | static void start_branch_trace(struct trace_array *tr) | |
121 | { | |
122 | enable_branch_tracing(tr); | |
123 | } | |
124 | ||
125 | static void stop_branch_trace(struct trace_array *tr) | |
126 | { | |
127 | disable_branch_tracing(); | |
128 | } | |
129 | ||
1c80025a | 130 | static int branch_trace_init(struct trace_array *tr) |
80e5ea45 | 131 | { |
80e5ea45 | 132 | start_branch_trace(tr); |
1c80025a | 133 | return 0; |
80e5ea45 SR |
134 | } |
135 | ||
136 | static void branch_trace_reset(struct trace_array *tr) | |
137 | { | |
138 | stop_branch_trace(tr); | |
139 | } | |
140 | ||
ae7462b4 ACM |
141 | static enum print_line_t trace_branch_print(struct trace_iterator *iter, |
142 | int flags) | |
f633cef0 SR |
143 | { |
144 | struct trace_branch *field; | |
145 | ||
2c9b238e | 146 | trace_assign_type(field, iter->ent); |
f633cef0 | 147 | |
2c9b238e | 148 | if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n", |
f633cef0 SR |
149 | field->correct ? " ok " : " MISS ", |
150 | field->func, | |
151 | field->file, | |
152 | field->line)) | |
153 | return TRACE_TYPE_PARTIAL_LINE; | |
154 | ||
d9793bd8 | 155 | return TRACE_TYPE_HANDLED; |
f633cef0 SR |
156 | } |
157 | ||
e302cf3f | 158 | |
f633cef0 SR |
159 | static struct trace_event trace_branch_event = { |
160 | .type = TRACE_BRANCH, | |
161 | .trace = trace_branch_print, | |
f633cef0 SR |
162 | }; |
163 | ||
002bb86d FW |
164 | static struct tracer branch_trace __read_mostly = |
165 | { | |
166 | .name = "branch", | |
167 | .init = branch_trace_init, | |
168 | .reset = branch_trace_reset, | |
169 | #ifdef CONFIG_FTRACE_SELFTEST | |
170 | .selftest = trace_selftest_startup_branch, | |
171 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
172 | }; | |
173 | ||
174 | __init static int init_branch_tracer(void) | |
175 | { | |
176 | int ret; | |
177 | ||
178 | ret = register_ftrace_event(&trace_branch_event); | |
179 | if (!ret) { | |
180 | printk(KERN_WARNING "Warning: could not register " | |
181 | "branch events\n"); | |
182 | return 1; | |
183 | } | |
184 | return register_tracer(&branch_trace); | |
185 | } | |
186 | device_initcall(init_branch_tracer); | |
187 | ||
52f232cb SR |
188 | #else |
189 | static inline | |
9f029e83 | 190 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
191 | { |
192 | } | |
2ed84eeb | 193 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 194 | |
9f029e83 | 195 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 196 | { |
52f232cb SR |
197 | /* |
198 | * I would love to have a trace point here instead, but the | |
199 | * trace point code is so inundated with unlikely and likely | |
200 | * conditions that the recursive nightmare that exists is too | |
201 | * much to try to get working. At least for now. | |
202 | */ | |
203 | trace_likely_condition(f, val, expect); | |
204 | ||
1f0d69a9 SR |
205 | /* FIXME: Make this atomic! */ |
206 | if (val == expect) | |
207 | f->correct++; | |
208 | else | |
209 | f->incorrect++; | |
210 | } | |
211 | EXPORT_SYMBOL(ftrace_likely_update); | |
212 | ||
e302cf3f FW |
213 | extern unsigned long __start_annotated_branch_profile[]; |
214 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 215 | |
e302cf3f | 216 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 217 | { |
e302cf3f FW |
218 | seq_printf(m, " correct incorrect %% "); |
219 | seq_printf(m, " Function " | |
220 | " File Line\n" | |
221 | " ------- --------- - " | |
222 | " -------- " | |
223 | " ---- ----\n"); | |
224 | return 0; | |
1f0d69a9 SR |
225 | } |
226 | ||
e302cf3f | 227 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 228 | { |
e302cf3f | 229 | long percent; |
1f0d69a9 | 230 | |
e302cf3f FW |
231 | if (p->correct) { |
232 | percent = p->incorrect * 100; | |
233 | percent /= p->correct + p->incorrect; | |
234 | } else | |
235 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 236 | |
e302cf3f | 237 | return percent; |
1f0d69a9 SR |
238 | } |
239 | ||
e302cf3f | 240 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 241 | { |
9f029e83 | 242 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 243 | const char *f; |
bac28bfe | 244 | long percent; |
1f0d69a9 | 245 | |
1f0d69a9 SR |
246 | /* Only print the file, not the path */ |
247 | f = p->file + strlen(p->file); | |
248 | while (f >= p->file && *f != '/') | |
249 | f--; | |
250 | f++; | |
251 | ||
2bcd521a SR |
252 | /* |
253 | * The miss is overlayed on correct, and hit on incorrect. | |
254 | */ | |
e302cf3f | 255 | percent = get_incorrect_percent(p); |
1f0d69a9 | 256 | |
bac28bfe SR |
257 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
258 | if (percent < 0) | |
259 | seq_printf(m, " X "); | |
260 | else | |
261 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
262 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
263 | return 0; | |
264 | } | |
265 | ||
e302cf3f FW |
266 | static void *annotated_branch_stat_start(void) |
267 | { | |
268 | return __start_annotated_branch_profile; | |
269 | } | |
1f0d69a9 | 270 | |
e302cf3f FW |
271 | static void * |
272 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 273 | { |
e302cf3f | 274 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 275 | |
e302cf3f | 276 | ++p; |
1f0d69a9 | 277 | |
e302cf3f FW |
278 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
279 | return NULL; | |
280 | ||
281 | return p; | |
1f0d69a9 SR |
282 | } |
283 | ||
e302cf3f FW |
284 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
285 | { | |
286 | struct ftrace_branch_data *a = p1; | |
287 | struct ftrace_branch_data *b = p2; | |
288 | ||
289 | long percent_a, percent_b; | |
290 | ||
291 | percent_a = get_incorrect_percent(a); | |
292 | percent_b = get_incorrect_percent(b); | |
293 | ||
294 | if (percent_a < percent_b) | |
295 | return -1; | |
296 | if (percent_a > percent_b) | |
297 | return 1; | |
298 | else | |
299 | return 0; | |
300 | } | |
1f0d69a9 | 301 | |
002bb86d FW |
302 | static struct tracer_stat annotated_branch_stats = { |
303 | .name = "branch_annotated", | |
304 | .stat_start = annotated_branch_stat_start, | |
305 | .stat_next = annotated_branch_stat_next, | |
306 | .stat_cmp = annotated_branch_stat_cmp, | |
307 | .stat_headers = annotated_branch_stat_headers, | |
308 | .stat_show = branch_stat_show | |
309 | }; | |
310 | ||
311 | __init static int init_annotated_branch_stats(void) | |
312 | { | |
313 | int ret; | |
314 | ||
315 | ret = register_stat_tracer(&annotated_branch_stats); | |
316 | if (!ret) { | |
317 | printk(KERN_WARNING "Warning: could not register " | |
318 | "annotated branches stats\n"); | |
319 | return 1; | |
320 | } | |
321 | return 0; | |
322 | } | |
323 | fs_initcall(init_annotated_branch_stats); | |
324 | ||
2bcd521a | 325 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 326 | |
e302cf3f FW |
327 | extern unsigned long __start_branch_profile[]; |
328 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 329 | |
e302cf3f FW |
330 | static int all_branch_stat_headers(struct seq_file *m) |
331 | { | |
332 | seq_printf(m, " miss hit %% "); | |
333 | seq_printf(m, " Function " | |
334 | " File Line\n" | |
335 | " ------- --------- - " | |
336 | " -------- " | |
337 | " ---- ----\n"); | |
338 | return 0; | |
339 | } | |
1f0d69a9 | 340 | |
e302cf3f | 341 | static void *all_branch_stat_start(void) |
1f0d69a9 | 342 | { |
e302cf3f FW |
343 | return __start_branch_profile; |
344 | } | |
345 | ||
346 | static void * | |
347 | all_branch_stat_next(void *v, int idx) | |
348 | { | |
349 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 350 | |
e302cf3f | 351 | ++p; |
1f0d69a9 | 352 | |
e302cf3f FW |
353 | if ((void *)p >= (void *)__stop_branch_profile) |
354 | return NULL; | |
1f0d69a9 | 355 | |
e302cf3f FW |
356 | return p; |
357 | } | |
2bcd521a | 358 | |
002bb86d FW |
359 | static struct tracer_stat all_branch_stats = { |
360 | .name = "branch_all", | |
034939b6 FW |
361 | .stat_start = all_branch_stat_start, |
362 | .stat_next = all_branch_stat_next, | |
363 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 364 | .stat_show = branch_stat_show |
034939b6 | 365 | }; |
e302cf3f | 366 | |
002bb86d | 367 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 368 | { |
e302cf3f | 369 | int ret; |
002bb86d FW |
370 | |
371 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 372 | if (!ret) { |
002bb86d FW |
373 | printk(KERN_WARNING "Warning: could not register " |
374 | "all branches stats\n"); | |
e302cf3f FW |
375 | return 1; |
376 | } | |
002bb86d | 377 | return 0; |
e302cf3f | 378 | } |
002bb86d FW |
379 | fs_initcall(all_annotated_branch_stats); |
380 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |