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 | ||
0a987751 | 55 | event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry)); |
52f232cb SR |
56 | if (!event) |
57 | goto out; | |
58 | ||
59 | pc = preempt_count(); | |
60 | entry = ring_buffer_event_data(event); | |
61 | tracing_generic_entry_update(&entry->ent, flags, pc); | |
9f029e83 | 62 | entry->ent.type = TRACE_BRANCH; |
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 | ||
0a987751 | 77 | ring_buffer_unlock_commit(tr->buffer, event); |
52f232cb SR |
78 | |
79 | out: | |
80 | atomic_dec(&tr->data[cpu]->disabled); | |
a5e25883 | 81 | local_irq_restore(flags); |
52f232cb SR |
82 | } |
83 | ||
84 | static inline | |
9f029e83 | 85 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 86 | { |
9f029e83 | 87 | if (!branch_tracing_enabled) |
52f232cb SR |
88 | return; |
89 | ||
90 | probe_likely_condition(f, val, expect); | |
91 | } | |
92 | ||
9f029e83 | 93 | int enable_branch_tracing(struct trace_array *tr) |
52f232cb SR |
94 | { |
95 | int ret = 0; | |
96 | ||
9f029e83 SR |
97 | mutex_lock(&branch_tracing_mutex); |
98 | branch_tracer = tr; | |
52f232cb SR |
99 | /* |
100 | * Must be seen before enabling. The reader is a condition | |
101 | * where we do not need a matching rmb() | |
102 | */ | |
103 | smp_wmb(); | |
9f029e83 SR |
104 | branch_tracing_enabled++; |
105 | mutex_unlock(&branch_tracing_mutex); | |
52f232cb SR |
106 | |
107 | return ret; | |
108 | } | |
109 | ||
9f029e83 | 110 | void disable_branch_tracing(void) |
52f232cb | 111 | { |
9f029e83 | 112 | mutex_lock(&branch_tracing_mutex); |
52f232cb | 113 | |
9f029e83 | 114 | if (!branch_tracing_enabled) |
52f232cb SR |
115 | goto out_unlock; |
116 | ||
9f029e83 | 117 | branch_tracing_enabled--; |
52f232cb SR |
118 | |
119 | out_unlock: | |
9f029e83 | 120 | mutex_unlock(&branch_tracing_mutex); |
52f232cb | 121 | } |
80e5ea45 SR |
122 | |
123 | static void start_branch_trace(struct trace_array *tr) | |
124 | { | |
125 | enable_branch_tracing(tr); | |
126 | } | |
127 | ||
128 | static void stop_branch_trace(struct trace_array *tr) | |
129 | { | |
130 | disable_branch_tracing(); | |
131 | } | |
132 | ||
1c80025a | 133 | static int branch_trace_init(struct trace_array *tr) |
80e5ea45 | 134 | { |
f04109bf | 135 | tracing_reset_online_cpus(tr); |
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 | ||
e302cf3f | 162 | |
f633cef0 SR |
163 | static struct trace_event trace_branch_event = { |
164 | .type = TRACE_BRANCH, | |
165 | .trace = trace_branch_print, | |
166 | .latency_trace = trace_branch_print, | |
f633cef0 SR |
167 | }; |
168 | ||
002bb86d FW |
169 | static struct tracer branch_trace __read_mostly = |
170 | { | |
171 | .name = "branch", | |
172 | .init = branch_trace_init, | |
173 | .reset = branch_trace_reset, | |
174 | #ifdef CONFIG_FTRACE_SELFTEST | |
175 | .selftest = trace_selftest_startup_branch, | |
176 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
177 | }; | |
178 | ||
179 | __init static int init_branch_tracer(void) | |
180 | { | |
181 | int ret; | |
182 | ||
183 | ret = register_ftrace_event(&trace_branch_event); | |
184 | if (!ret) { | |
185 | printk(KERN_WARNING "Warning: could not register " | |
186 | "branch events\n"); | |
187 | return 1; | |
188 | } | |
189 | return register_tracer(&branch_trace); | |
190 | } | |
191 | device_initcall(init_branch_tracer); | |
192 | ||
52f232cb SR |
193 | #else |
194 | static inline | |
9f029e83 | 195 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
196 | { |
197 | } | |
2ed84eeb | 198 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 199 | |
9f029e83 | 200 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 201 | { |
52f232cb SR |
202 | /* |
203 | * I would love to have a trace point here instead, but the | |
204 | * trace point code is so inundated with unlikely and likely | |
205 | * conditions that the recursive nightmare that exists is too | |
206 | * much to try to get working. At least for now. | |
207 | */ | |
208 | trace_likely_condition(f, val, expect); | |
209 | ||
1f0d69a9 SR |
210 | /* FIXME: Make this atomic! */ |
211 | if (val == expect) | |
212 | f->correct++; | |
213 | else | |
214 | f->incorrect++; | |
215 | } | |
216 | EXPORT_SYMBOL(ftrace_likely_update); | |
217 | ||
e302cf3f FW |
218 | extern unsigned long __start_annotated_branch_profile[]; |
219 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 220 | |
e302cf3f | 221 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 222 | { |
e302cf3f FW |
223 | seq_printf(m, " correct incorrect %% "); |
224 | seq_printf(m, " Function " | |
225 | " File Line\n" | |
226 | " ------- --------- - " | |
227 | " -------- " | |
228 | " ---- ----\n"); | |
229 | return 0; | |
1f0d69a9 SR |
230 | } |
231 | ||
e302cf3f | 232 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 233 | { |
e302cf3f | 234 | long percent; |
1f0d69a9 | 235 | |
e302cf3f FW |
236 | if (p->correct) { |
237 | percent = p->incorrect * 100; | |
238 | percent /= p->correct + p->incorrect; | |
239 | } else | |
240 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 241 | |
e302cf3f | 242 | return percent; |
1f0d69a9 SR |
243 | } |
244 | ||
e302cf3f | 245 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 246 | { |
9f029e83 | 247 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 248 | const char *f; |
bac28bfe | 249 | long percent; |
1f0d69a9 | 250 | |
1f0d69a9 SR |
251 | /* Only print the file, not the path */ |
252 | f = p->file + strlen(p->file); | |
253 | while (f >= p->file && *f != '/') | |
254 | f--; | |
255 | f++; | |
256 | ||
2bcd521a SR |
257 | /* |
258 | * The miss is overlayed on correct, and hit on incorrect. | |
259 | */ | |
e302cf3f | 260 | percent = get_incorrect_percent(p); |
1f0d69a9 | 261 | |
bac28bfe SR |
262 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
263 | if (percent < 0) | |
264 | seq_printf(m, " X "); | |
265 | else | |
266 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
267 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
268 | return 0; | |
269 | } | |
270 | ||
e302cf3f FW |
271 | static void *annotated_branch_stat_start(void) |
272 | { | |
273 | return __start_annotated_branch_profile; | |
274 | } | |
1f0d69a9 | 275 | |
e302cf3f FW |
276 | static void * |
277 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 278 | { |
e302cf3f | 279 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 280 | |
e302cf3f | 281 | ++p; |
1f0d69a9 | 282 | |
e302cf3f FW |
283 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
284 | return NULL; | |
285 | ||
286 | return p; | |
1f0d69a9 SR |
287 | } |
288 | ||
e302cf3f FW |
289 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
290 | { | |
291 | struct ftrace_branch_data *a = p1; | |
292 | struct ftrace_branch_data *b = p2; | |
293 | ||
294 | long percent_a, percent_b; | |
295 | ||
296 | percent_a = get_incorrect_percent(a); | |
297 | percent_b = get_incorrect_percent(b); | |
298 | ||
299 | if (percent_a < percent_b) | |
300 | return -1; | |
301 | if (percent_a > percent_b) | |
302 | return 1; | |
303 | else | |
304 | return 0; | |
305 | } | |
1f0d69a9 | 306 | |
002bb86d FW |
307 | static struct tracer_stat annotated_branch_stats = { |
308 | .name = "branch_annotated", | |
309 | .stat_start = annotated_branch_stat_start, | |
310 | .stat_next = annotated_branch_stat_next, | |
311 | .stat_cmp = annotated_branch_stat_cmp, | |
312 | .stat_headers = annotated_branch_stat_headers, | |
313 | .stat_show = branch_stat_show | |
314 | }; | |
315 | ||
316 | __init static int init_annotated_branch_stats(void) | |
317 | { | |
318 | int ret; | |
319 | ||
320 | ret = register_stat_tracer(&annotated_branch_stats); | |
321 | if (!ret) { | |
322 | printk(KERN_WARNING "Warning: could not register " | |
323 | "annotated branches stats\n"); | |
324 | return 1; | |
325 | } | |
326 | return 0; | |
327 | } | |
328 | fs_initcall(init_annotated_branch_stats); | |
329 | ||
2bcd521a | 330 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 331 | |
e302cf3f FW |
332 | extern unsigned long __start_branch_profile[]; |
333 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 334 | |
e302cf3f FW |
335 | static int all_branch_stat_headers(struct seq_file *m) |
336 | { | |
337 | seq_printf(m, " miss hit %% "); | |
338 | seq_printf(m, " Function " | |
339 | " File Line\n" | |
340 | " ------- --------- - " | |
341 | " -------- " | |
342 | " ---- ----\n"); | |
343 | return 0; | |
344 | } | |
1f0d69a9 | 345 | |
e302cf3f | 346 | static void *all_branch_stat_start(void) |
1f0d69a9 | 347 | { |
e302cf3f FW |
348 | return __start_branch_profile; |
349 | } | |
350 | ||
351 | static void * | |
352 | all_branch_stat_next(void *v, int idx) | |
353 | { | |
354 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 355 | |
e302cf3f | 356 | ++p; |
1f0d69a9 | 357 | |
e302cf3f FW |
358 | if ((void *)p >= (void *)__stop_branch_profile) |
359 | return NULL; | |
1f0d69a9 | 360 | |
e302cf3f FW |
361 | return p; |
362 | } | |
2bcd521a | 363 | |
002bb86d FW |
364 | static struct tracer_stat all_branch_stats = { |
365 | .name = "branch_all", | |
034939b6 FW |
366 | .stat_start = all_branch_stat_start, |
367 | .stat_next = all_branch_stat_next, | |
368 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 369 | .stat_show = branch_stat_show |
034939b6 | 370 | }; |
e302cf3f | 371 | |
002bb86d | 372 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 373 | { |
e302cf3f | 374 | int ret; |
002bb86d FW |
375 | |
376 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 377 | if (!ret) { |
002bb86d FW |
378 | printk(KERN_WARNING "Warning: could not register " |
379 | "all branches stats\n"); | |
e302cf3f FW |
380 | return 1; |
381 | } | |
002bb86d | 382 | return 0; |
e302cf3f | 383 | } |
002bb86d FW |
384 | fs_initcall(all_annotated_branch_stats); |
385 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |