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; |
a7603ff4 | 35 | struct trace_array_cpu *data; |
52f232cb | 36 | struct ring_buffer_event *event; |
9f029e83 | 37 | struct trace_branch *entry; |
8f6e8a31 | 38 | struct ring_buffer *buffer; |
0a987751 | 39 | unsigned long flags; |
52f232cb SR |
40 | int cpu, pc; |
41 | const char *p; | |
42 | ||
43 | /* | |
44 | * I would love to save just the ftrace_likely_data pointer, but | |
45 | * this code can also be used by modules. Ugly things can happen | |
46 | * if the module is unloaded, and then we go and read the | |
47 | * pointer. This is slower, but much safer. | |
48 | */ | |
49 | ||
50 | if (unlikely(!tr)) | |
51 | return; | |
52 | ||
a5e25883 | 53 | local_irq_save(flags); |
52f232cb | 54 | cpu = raw_smp_processor_id(); |
153e8ed9 | 55 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
a7603ff4 | 56 | if (atomic_inc_return(&data->disabled) != 1) |
52f232cb SR |
57 | goto out; |
58 | ||
51a763dd | 59 | pc = preempt_count(); |
153e8ed9 | 60 | buffer = tr->trace_buffer.buffer; |
8f6e8a31 | 61 | event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH, |
51a763dd | 62 | sizeof(*entry), flags, pc); |
52f232cb SR |
63 | if (!event) |
64 | goto out; | |
65 | ||
52f232cb | 66 | entry = ring_buffer_event_data(event); |
52f232cb SR |
67 | |
68 | /* Strip off the path, only save the file */ | |
69 | p = f->file + strlen(f->file); | |
70 | while (p >= f->file && *p != '/') | |
71 | p--; | |
72 | p++; | |
73 | ||
74 | strncpy(entry->func, f->func, TRACE_FUNC_SIZE); | |
75 | strncpy(entry->file, p, TRACE_FILE_SIZE); | |
76 | entry->func[TRACE_FUNC_SIZE] = 0; | |
77 | entry->file[TRACE_FILE_SIZE] = 0; | |
78 | entry->line = f->line; | |
79 | entry->correct = val == expect; | |
80 | ||
f306cc82 | 81 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 82 | __buffer_unlock_commit(buffer, event); |
52f232cb SR |
83 | |
84 | out: | |
a7603ff4 | 85 | atomic_dec(&data->disabled); |
a5e25883 | 86 | local_irq_restore(flags); |
52f232cb SR |
87 | } |
88 | ||
89 | static inline | |
9f029e83 | 90 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb | 91 | { |
9f029e83 | 92 | if (!branch_tracing_enabled) |
52f232cb SR |
93 | return; |
94 | ||
95 | probe_likely_condition(f, val, expect); | |
96 | } | |
97 | ||
9f029e83 | 98 | int enable_branch_tracing(struct trace_array *tr) |
52f232cb | 99 | { |
9f029e83 SR |
100 | mutex_lock(&branch_tracing_mutex); |
101 | branch_tracer = tr; | |
52f232cb SR |
102 | /* |
103 | * Must be seen before enabling. The reader is a condition | |
104 | * where we do not need a matching rmb() | |
105 | */ | |
106 | smp_wmb(); | |
9f029e83 SR |
107 | branch_tracing_enabled++; |
108 | mutex_unlock(&branch_tracing_mutex); | |
52f232cb | 109 | |
f54fc98a | 110 | return 0; |
52f232cb SR |
111 | } |
112 | ||
9f029e83 | 113 | void disable_branch_tracing(void) |
52f232cb | 114 | { |
9f029e83 | 115 | mutex_lock(&branch_tracing_mutex); |
52f232cb | 116 | |
9f029e83 | 117 | if (!branch_tracing_enabled) |
52f232cb SR |
118 | goto out_unlock; |
119 | ||
9f029e83 | 120 | branch_tracing_enabled--; |
52f232cb SR |
121 | |
122 | out_unlock: | |
9f029e83 | 123 | mutex_unlock(&branch_tracing_mutex); |
52f232cb | 124 | } |
80e5ea45 SR |
125 | |
126 | static void start_branch_trace(struct trace_array *tr) | |
127 | { | |
128 | enable_branch_tracing(tr); | |
129 | } | |
130 | ||
131 | static void stop_branch_trace(struct trace_array *tr) | |
132 | { | |
133 | disable_branch_tracing(); | |
134 | } | |
135 | ||
1c80025a | 136 | static int branch_trace_init(struct trace_array *tr) |
80e5ea45 | 137 | { |
80e5ea45 | 138 | start_branch_trace(tr); |
1c80025a | 139 | return 0; |
80e5ea45 SR |
140 | } |
141 | ||
142 | static void branch_trace_reset(struct trace_array *tr) | |
143 | { | |
144 | stop_branch_trace(tr); | |
145 | } | |
146 | ||
ae7462b4 | 147 | static enum print_line_t trace_branch_print(struct trace_iterator *iter, |
a9a57763 | 148 | int flags, struct trace_event *event) |
f633cef0 SR |
149 | { |
150 | struct trace_branch *field; | |
151 | ||
2c9b238e | 152 | trace_assign_type(field, iter->ent); |
f633cef0 | 153 | |
2c9b238e | 154 | if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n", |
f633cef0 SR |
155 | field->correct ? " ok " : " MISS ", |
156 | field->func, | |
157 | field->file, | |
158 | field->line)) | |
159 | return TRACE_TYPE_PARTIAL_LINE; | |
160 | ||
d9793bd8 | 161 | return TRACE_TYPE_HANDLED; |
f633cef0 SR |
162 | } |
163 | ||
557055be Z |
164 | static void branch_print_header(struct seq_file *s) |
165 | { | |
166 | seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT" | |
167 | " FUNC:FILE:LINE\n"); | |
168 | seq_puts(s, "# | | | | | " | |
169 | " |\n"); | |
170 | } | |
e302cf3f | 171 | |
a9a57763 SR |
172 | static struct trace_event_functions trace_branch_funcs = { |
173 | .trace = trace_branch_print, | |
174 | }; | |
175 | ||
f633cef0 | 176 | static struct trace_event trace_branch_event = { |
ef18012b | 177 | .type = TRACE_BRANCH, |
a9a57763 | 178 | .funcs = &trace_branch_funcs, |
f633cef0 SR |
179 | }; |
180 | ||
002bb86d FW |
181 | static struct tracer branch_trace __read_mostly = |
182 | { | |
183 | .name = "branch", | |
184 | .init = branch_trace_init, | |
185 | .reset = branch_trace_reset, | |
186 | #ifdef CONFIG_FTRACE_SELFTEST | |
187 | .selftest = trace_selftest_startup_branch, | |
188 | #endif /* CONFIG_FTRACE_SELFTEST */ | |
557055be | 189 | .print_header = branch_print_header, |
002bb86d FW |
190 | }; |
191 | ||
192 | __init static int init_branch_tracer(void) | |
193 | { | |
194 | int ret; | |
195 | ||
196 | ret = register_ftrace_event(&trace_branch_event); | |
197 | if (!ret) { | |
198 | printk(KERN_WARNING "Warning: could not register " | |
199 | "branch events\n"); | |
200 | return 1; | |
201 | } | |
202 | return register_tracer(&branch_trace); | |
203 | } | |
6f415672 | 204 | core_initcall(init_branch_tracer); |
002bb86d | 205 | |
52f232cb SR |
206 | #else |
207 | static inline | |
9f029e83 | 208 | void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) |
52f232cb SR |
209 | { |
210 | } | |
2ed84eeb | 211 | #endif /* CONFIG_BRANCH_TRACER */ |
52f232cb | 212 | |
9f029e83 | 213 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) |
1f0d69a9 | 214 | { |
52f232cb SR |
215 | /* |
216 | * I would love to have a trace point here instead, but the | |
217 | * trace point code is so inundated with unlikely and likely | |
218 | * conditions that the recursive nightmare that exists is too | |
219 | * much to try to get working. At least for now. | |
220 | */ | |
221 | trace_likely_condition(f, val, expect); | |
222 | ||
1f0d69a9 SR |
223 | /* FIXME: Make this atomic! */ |
224 | if (val == expect) | |
225 | f->correct++; | |
226 | else | |
227 | f->incorrect++; | |
228 | } | |
229 | EXPORT_SYMBOL(ftrace_likely_update); | |
230 | ||
e302cf3f FW |
231 | extern unsigned long __start_annotated_branch_profile[]; |
232 | extern unsigned long __stop_annotated_branch_profile[]; | |
1f0d69a9 | 233 | |
e302cf3f | 234 | static int annotated_branch_stat_headers(struct seq_file *m) |
1f0d69a9 | 235 | { |
e302cf3f FW |
236 | seq_printf(m, " correct incorrect %% "); |
237 | seq_printf(m, " Function " | |
238 | " File Line\n" | |
239 | " ------- --------- - " | |
240 | " -------- " | |
241 | " ---- ----\n"); | |
242 | return 0; | |
1f0d69a9 SR |
243 | } |
244 | ||
e302cf3f | 245 | static inline long get_incorrect_percent(struct ftrace_branch_data *p) |
1f0d69a9 | 246 | { |
e302cf3f | 247 | long percent; |
1f0d69a9 | 248 | |
e302cf3f FW |
249 | if (p->correct) { |
250 | percent = p->incorrect * 100; | |
251 | percent /= p->correct + p->incorrect; | |
252 | } else | |
253 | percent = p->incorrect ? 100 : -1; | |
1f0d69a9 | 254 | |
e302cf3f | 255 | return percent; |
1f0d69a9 SR |
256 | } |
257 | ||
e302cf3f | 258 | static int branch_stat_show(struct seq_file *m, void *v) |
1f0d69a9 | 259 | { |
9f029e83 | 260 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 261 | const char *f; |
bac28bfe | 262 | long percent; |
1f0d69a9 | 263 | |
1f0d69a9 SR |
264 | /* Only print the file, not the path */ |
265 | f = p->file + strlen(p->file); | |
266 | while (f >= p->file && *f != '/') | |
267 | f--; | |
268 | f++; | |
269 | ||
2bcd521a SR |
270 | /* |
271 | * The miss is overlayed on correct, and hit on incorrect. | |
272 | */ | |
e302cf3f | 273 | percent = get_incorrect_percent(p); |
1f0d69a9 | 274 | |
bac28bfe SR |
275 | seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect); |
276 | if (percent < 0) | |
277 | seq_printf(m, " X "); | |
278 | else | |
279 | seq_printf(m, "%3ld ", percent); | |
1f0d69a9 SR |
280 | seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line); |
281 | return 0; | |
282 | } | |
283 | ||
42548008 | 284 | static void *annotated_branch_stat_start(struct tracer_stat *trace) |
e302cf3f FW |
285 | { |
286 | return __start_annotated_branch_profile; | |
287 | } | |
1f0d69a9 | 288 | |
e302cf3f FW |
289 | static void * |
290 | annotated_branch_stat_next(void *v, int idx) | |
1f0d69a9 | 291 | { |
e302cf3f | 292 | struct ftrace_branch_data *p = v; |
1f0d69a9 | 293 | |
e302cf3f | 294 | ++p; |
1f0d69a9 | 295 | |
e302cf3f FW |
296 | if ((void *)p >= (void *)__stop_annotated_branch_profile) |
297 | return NULL; | |
298 | ||
299 | return p; | |
1f0d69a9 SR |
300 | } |
301 | ||
e302cf3f FW |
302 | static int annotated_branch_stat_cmp(void *p1, void *p2) |
303 | { | |
304 | struct ftrace_branch_data *a = p1; | |
305 | struct ftrace_branch_data *b = p2; | |
306 | ||
307 | long percent_a, percent_b; | |
308 | ||
309 | percent_a = get_incorrect_percent(a); | |
310 | percent_b = get_incorrect_percent(b); | |
311 | ||
312 | if (percent_a < percent_b) | |
313 | return -1; | |
314 | if (percent_a > percent_b) | |
315 | return 1; | |
ede55c9d SR |
316 | |
317 | if (a->incorrect < b->incorrect) | |
318 | return -1; | |
319 | if (a->incorrect > b->incorrect) | |
320 | return 1; | |
321 | ||
322 | /* | |
323 | * Since the above shows worse (incorrect) cases | |
324 | * first, we continue that by showing best (correct) | |
325 | * cases last. | |
326 | */ | |
327 | if (a->correct > b->correct) | |
328 | return -1; | |
329 | if (a->correct < b->correct) | |
330 | return 1; | |
331 | ||
332 | return 0; | |
e302cf3f | 333 | } |
1f0d69a9 | 334 | |
002bb86d FW |
335 | static struct tracer_stat annotated_branch_stats = { |
336 | .name = "branch_annotated", | |
337 | .stat_start = annotated_branch_stat_start, | |
338 | .stat_next = annotated_branch_stat_next, | |
339 | .stat_cmp = annotated_branch_stat_cmp, | |
340 | .stat_headers = annotated_branch_stat_headers, | |
341 | .stat_show = branch_stat_show | |
342 | }; | |
343 | ||
344 | __init static int init_annotated_branch_stats(void) | |
345 | { | |
346 | int ret; | |
347 | ||
348 | ret = register_stat_tracer(&annotated_branch_stats); | |
349 | if (!ret) { | |
350 | printk(KERN_WARNING "Warning: could not register " | |
351 | "annotated branches stats\n"); | |
352 | return 1; | |
353 | } | |
354 | return 0; | |
355 | } | |
356 | fs_initcall(init_annotated_branch_stats); | |
357 | ||
2bcd521a | 358 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
2bcd521a | 359 | |
e302cf3f FW |
360 | extern unsigned long __start_branch_profile[]; |
361 | extern unsigned long __stop_branch_profile[]; | |
1f0d69a9 | 362 | |
e302cf3f FW |
363 | static int all_branch_stat_headers(struct seq_file *m) |
364 | { | |
365 | seq_printf(m, " miss hit %% "); | |
366 | seq_printf(m, " Function " | |
367 | " File Line\n" | |
368 | " ------- --------- - " | |
369 | " -------- " | |
370 | " ---- ----\n"); | |
371 | return 0; | |
372 | } | |
1f0d69a9 | 373 | |
42548008 | 374 | static void *all_branch_stat_start(struct tracer_stat *trace) |
1f0d69a9 | 375 | { |
e302cf3f FW |
376 | return __start_branch_profile; |
377 | } | |
378 | ||
379 | static void * | |
380 | all_branch_stat_next(void *v, int idx) | |
381 | { | |
382 | struct ftrace_branch_data *p = v; | |
1f0d69a9 | 383 | |
e302cf3f | 384 | ++p; |
1f0d69a9 | 385 | |
e302cf3f FW |
386 | if ((void *)p >= (void *)__stop_branch_profile) |
387 | return NULL; | |
1f0d69a9 | 388 | |
e302cf3f FW |
389 | return p; |
390 | } | |
2bcd521a | 391 | |
002bb86d FW |
392 | static struct tracer_stat all_branch_stats = { |
393 | .name = "branch_all", | |
034939b6 FW |
394 | .stat_start = all_branch_stat_start, |
395 | .stat_next = all_branch_stat_next, | |
396 | .stat_headers = all_branch_stat_headers, | |
002bb86d | 397 | .stat_show = branch_stat_show |
034939b6 | 398 | }; |
e302cf3f | 399 | |
002bb86d | 400 | __init static int all_annotated_branch_stats(void) |
e302cf3f | 401 | { |
e302cf3f | 402 | int ret; |
002bb86d FW |
403 | |
404 | ret = register_stat_tracer(&all_branch_stats); | |
e302cf3f | 405 | if (!ret) { |
002bb86d FW |
406 | printk(KERN_WARNING "Warning: could not register " |
407 | "all branches stats\n"); | |
e302cf3f FW |
408 | return 1; |
409 | } | |
002bb86d | 410 | return 0; |
e302cf3f | 411 | } |
002bb86d FW |
412 | fs_initcall(all_annotated_branch_stats); |
413 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |