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; |
0a987751 | 37 | unsigned long flags; |
52f232cb SR |
38 | int cpu, pc; |
39 | const char *p; | |
40 | ||
41 | /* | |
42 | * I would love to save just the ftrace_likely_data pointer, but | |
43 | * this code can also be used by modules. Ugly things can happen | |
44 | * if the module is unloaded, and then we go and read the | |
45 | * pointer. This is slower, but much safer. | |
46 | */ | |
47 | ||
48 | if (unlikely(!tr)) | |
49 | return; | |
50 | ||
a5e25883 | 51 | local_irq_save(flags); |
52f232cb SR |
52 | cpu = raw_smp_processor_id(); |
53 | if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) | |
54 | goto out; | |
55 | ||
51a763dd | 56 | pc = preempt_count(); |
c8647b28 | 57 | event = trace_buffer_lock_reserve(tr->buffer, TRACE_BRANCH, |
51a763dd | 58 | sizeof(*entry), flags, pc); |
52f232cb SR |
59 | if (!event) |
60 | goto out; | |
61 | ||
52f232cb | 62 | entry = ring_buffer_event_data(event); |
52f232cb SR |
63 | |
64 | /* Strip off the path, only save the file */ | |
65 | p = f->file + strlen(f->file); | |
66 | while (p >= f->file && *p != '/') | |
67 | p--; | |
68 | p++; | |
69 | ||
70 | strncpy(entry->func, f->func, TRACE_FUNC_SIZE); | |
71 | strncpy(entry->file, p, TRACE_FILE_SIZE); | |
72 | entry->func[TRACE_FUNC_SIZE] = 0; | |
73 | entry->file[TRACE_FILE_SIZE] = 0; | |
74 | entry->line = f->line; | |
75 | entry->correct = val == expect; | |
76 | ||
eb02ce01 TZ |
77 | if (!filter_check_discard(call, entry, tr->buffer, event)) |
78 | ring_buffer_unlock_commit(tr->buffer, event); | |
52f232cb SR |
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 | 95 | { |
9f029e83 SR |
96 | mutex_lock(&branch_tracing_mutex); |
97 | branch_tracer = tr; | |
52f232cb SR |
98 | /* |
99 | * Must be seen before enabling. The reader is a condition | |
100 | * where we do not need a matching rmb() | |
101 | */ | |
102 | smp_wmb(); | |
9f029e83 SR |
103 | branch_tracing_enabled++; |
104 | mutex_unlock(&branch_tracing_mutex); | |
52f232cb | 105 | |
f54fc98a | 106 | return 0; |
52f232cb SR |
107 | } |
108 | ||
9f029e83 | 109 | void disable_branch_tracing(void) |
52f232cb | 110 | { |
9f029e83 | 111 | mutex_lock(&branch_tracing_mutex); |
52f232cb | 112 | |
9f029e83 | 113 | if (!branch_tracing_enabled) |
52f232cb SR |
114 | goto out_unlock; |
115 | ||
9f029e83 | 116 | branch_tracing_enabled--; |
52f232cb SR |
117 | |
118 | out_unlock: | |
9f029e83 | 119 | mutex_unlock(&branch_tracing_mutex); |
52f232cb | 120 | } |
80e5ea45 SR |
121 | |
122 | static void start_branch_trace(struct trace_array *tr) | |
123 | { | |
124 | enable_branch_tracing(tr); | |
125 | } | |
126 | ||
127 | static void stop_branch_trace(struct trace_array *tr) | |
128 | { | |
129 | disable_branch_tracing(); | |
130 | } | |
131 | ||
1c80025a | 132 | static int branch_trace_init(struct trace_array *tr) |
80e5ea45 | 133 | { |
80e5ea45 | 134 | start_branch_trace(tr); |
1c80025a | 135 | return 0; |
80e5ea45 SR |
136 | } |
137 | ||
138 | static void branch_trace_reset(struct trace_array *tr) | |
139 | { | |
140 | stop_branch_trace(tr); | |
141 | } | |
142 | ||
ae7462b4 ACM |
143 | static enum print_line_t trace_branch_print(struct trace_iterator *iter, |
144 | int flags) | |
f633cef0 SR |
145 | { |
146 | struct trace_branch *field; | |
147 | ||
2c9b238e | 148 | trace_assign_type(field, iter->ent); |
f633cef0 | 149 | |
2c9b238e | 150 | if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n", |
f633cef0 SR |
151 | field->correct ? " ok " : " MISS ", |
152 | field->func, | |
153 | field->file, | |
154 | field->line)) | |
155 | return TRACE_TYPE_PARTIAL_LINE; | |
156 | ||
d9793bd8 | 157 | return TRACE_TYPE_HANDLED; |
f633cef0 SR |
158 | } |
159 | ||
557055be Z |
160 | static void branch_print_header(struct seq_file *s) |
161 | { | |
162 | seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT" | |
163 | " FUNC:FILE:LINE\n"); | |
164 | seq_puts(s, "# | | | | | " | |
165 | " |\n"); | |
166 | } | |
e302cf3f | 167 | |
f633cef0 | 168 | static struct trace_event trace_branch_event = { |
ef18012b | 169 | .type = TRACE_BRANCH, |
f633cef0 | 170 | .trace = trace_branch_print, |
f633cef0 SR |
171 | }; |
172 | ||
002bb86d FW |
173 | static struct tracer branch_trace __read_mostly = |
174 | { | |
175 | .name = "branch", | |
176 | .init = branch_trace_init, | |
177 | .reset = branch_trace_reset, | |
178 | #ifdef CONFIG_FTRACE_SELFTEST | |
179 | .selftest = trace_selftest_startup_branch, | |
180 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
557055be | 181 | .print_header = branch_print_header, |
002bb86d FW |
182 | }; |
183 | ||
184 | __init static int init_branch_tracer(void) | |
185 | { | |
186 | int ret; | |
187 | ||
188 | ret = register_ftrace_event(&trace_branch_event); | |
189 | if (!ret) { | |
190 | printk(KERN_WARNING "Warning: could not register " | |
191 | "branch events\n"); | |
192 | return 1; | |
193 | } | |
194 | return register_tracer(&branch_trace); | |
195 | } | |
196 | device_initcall(init_branch_tracer); | |
197 | ||
52f232cb SR |
198 | #else |
199 | static inline | |
9f029e83 | 200 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
201 | { |
202 | } | |
2ed84eeb | 203 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 204 | |
9f029e83 | 205 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 206 | { |
52f232cb SR |
207 | /* |
208 | * I would love to have a trace point here instead, but the | |
209 | * trace point code is so inundated with unlikely and likely | |
210 | * conditions that the recursive nightmare that exists is too | |
211 | * much to try to get working. At least for now. | |
212 | */ | |
213 | trace_likely_condition(f, val, expect); | |
214 | ||
1f0d69a9 SR |
215 | /* FIXME: Make this atomic! */ |
216 | if (val == expect) | |
217 | f->correct++; | |
218 | else | |
219 | f->incorrect++; | |
220 | } | |
221 | EXPORT_SYMBOL(ftrace_likely_update); | |
222 | ||
e302cf3f FW |
223 | extern unsigned long __start_annotated_branch_profile[]; |
224 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 225 | |
e302cf3f | 226 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 227 | { |
e302cf3f FW |
228 | seq_printf(m, " correct incorrect %% "); |
229 | seq_printf(m, " Function " | |
230 | " File Line\n" | |
231 | " ------- --------- - " | |
232 | " -------- " | |
233 | " ---- ----\n"); | |
234 | return 0; | |
1f0d69a9 SR |
235 | } |
236 | ||
e302cf3f | 237 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 238 | { |
e302cf3f | 239 | long percent; |
1f0d69a9 | 240 | |
e302cf3f FW |
241 | if (p->correct) { |
242 | percent = p->incorrect * 100; | |
243 | percent /= p->correct + p->incorrect; | |
244 | } else | |
245 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 246 | |
e302cf3f | 247 | return percent; |
1f0d69a9 SR |
248 | } |
249 | ||
e302cf3f | 250 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 251 | { |
9f029e83 | 252 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 253 | const char *f; |
bac28bfe | 254 | long percent; |
1f0d69a9 | 255 | |
1f0d69a9 SR |
256 | /* Only print the file, not the path */ |
257 | f = p->file + strlen(p->file); | |
258 | while (f >= p->file && *f != '/') | |
259 | f--; | |
260 | f++; | |
261 | ||
2bcd521a SR |
262 | /* |
263 | * The miss is overlayed on correct, and hit on incorrect. | |
264 | */ | |
e302cf3f | 265 | percent = get_incorrect_percent(p); |
1f0d69a9 | 266 | |
bac28bfe SR |
267 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
268 | if (percent < 0) | |
269 | seq_printf(m, " X "); | |
270 | else | |
271 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
272 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
273 | return 0; | |
274 | } | |
275 | ||
42548008 | 276 | static void *annotated_branch_stat_start(struct tracer_stat *trace) |
e302cf3f FW |
277 | { |
278 | return __start_annotated_branch_profile; | |
279 | } | |
1f0d69a9 | 280 | |
e302cf3f FW |
281 | static void * |
282 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 283 | { |
e302cf3f | 284 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 285 | |
e302cf3f | 286 | ++p; |
1f0d69a9 | 287 | |
e302cf3f FW |
288 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
289 | return NULL; | |
290 | ||
291 | return p; | |
1f0d69a9 SR |
292 | } |
293 | ||
e302cf3f FW |
294 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
295 | { | |
296 | struct ftrace_branch_data *a = p1; | |
297 | struct ftrace_branch_data *b = p2; | |
298 | ||
299 | long percent_a, percent_b; | |
300 | ||
301 | percent_a = get_incorrect_percent(a); | |
302 | percent_b = get_incorrect_percent(b); | |
303 | ||
304 | if (percent_a < percent_b) | |
305 | return -1; | |
306 | if (percent_a > percent_b) | |
307 | return 1; | |
308 | else | |
309 | return 0; | |
310 | } | |
1f0d69a9 | 311 | |
002bb86d FW |
312 | static struct tracer_stat annotated_branch_stats = { |
313 | .name = "branch_annotated", | |
314 | .stat_start = annotated_branch_stat_start, | |
315 | .stat_next = annotated_branch_stat_next, | |
316 | .stat_cmp = annotated_branch_stat_cmp, | |
317 | .stat_headers = annotated_branch_stat_headers, | |
318 | .stat_show = branch_stat_show | |
319 | }; | |
320 | ||
321 | __init static int init_annotated_branch_stats(void) | |
322 | { | |
323 | int ret; | |
324 | ||
325 | ret = register_stat_tracer(&annotated_branch_stats); | |
326 | if (!ret) { | |
327 | printk(KERN_WARNING "Warning: could not register " | |
328 | "annotated branches stats\n"); | |
329 | return 1; | |
330 | } | |
331 | return 0; | |
332 | } | |
333 | fs_initcall(init_annotated_branch_stats); | |
334 | ||
2bcd521a | 335 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 336 | |
e302cf3f FW |
337 | extern unsigned long __start_branch_profile[]; |
338 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 339 | |
e302cf3f FW |
340 | static int all_branch_stat_headers(struct seq_file *m) |
341 | { | |
342 | seq_printf(m, " miss hit %% "); | |
343 | seq_printf(m, " Function " | |
344 | " File Line\n" | |
345 | " ------- --------- - " | |
346 | " -------- " | |
347 | " ---- ----\n"); | |
348 | return 0; | |
349 | } | |
1f0d69a9 | 350 | |
42548008 | 351 | static void *all_branch_stat_start(struct tracer_stat *trace) |
1f0d69a9 | 352 | { |
e302cf3f FW |
353 | return __start_branch_profile; |
354 | } | |
355 | ||
356 | static void * | |
357 | all_branch_stat_next(void *v, int idx) | |
358 | { | |
359 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 360 | |
e302cf3f | 361 | ++p; |
1f0d69a9 | 362 | |
e302cf3f FW |
363 | if ((void *)p >= (void *)__stop_branch_profile) |
364 | return NULL; | |
1f0d69a9 | 365 | |
e302cf3f FW |
366 | return p; |
367 | } | |
2bcd521a | 368 | |
002bb86d FW |
369 | static struct tracer_stat all_branch_stats = { |
370 | .name = "branch_all", | |
034939b6 FW |
371 | .stat_start = all_branch_stat_start, |
372 | .stat_next = all_branch_stat_next, | |
373 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 374 | .stat_show = branch_stat_show |
034939b6 | 375 | }; |
e302cf3f | 376 | |
002bb86d | 377 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 378 | { |
e302cf3f | 379 | int ret; |
002bb86d FW |
380 | |
381 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 382 | if (!ret) { |
002bb86d FW |
383 | printk(KERN_WARNING "Warning: could not register " |
384 | "all branches stats\n"); | |
e302cf3f FW |
385 | return 1; |
386 | } | |
002bb86d | 387 | return 0; |
e302cf3f | 388 | } |
002bb86d FW |
389 | fs_initcall(all_annotated_branch_stats); |
390 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |