4 * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
6 #include <linux/kallsyms.h>
7 #include <linux/seq_file.h>
8 #include <linux/spinlock.h>
9 #include <linux/irqflags.h>
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>
16 #include <asm/local.h>
19 #include "trace_stat.h"
20 #include "trace_output.h"
22 #ifdef CONFIG_BRANCH_TRACER
24 static struct tracer branch_trace;
25 static int branch_tracing_enabled __read_mostly;
26 static DEFINE_MUTEX(branch_tracing_mutex);
28 static struct trace_array *branch_tracer;
31 probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
33 struct ftrace_event_call *call = &event_branch;
34 struct trace_array *tr = branch_tracer;
35 struct ring_buffer_event *event;
36 struct trace_branch *entry;
37 struct ring_buffer *buffer;
43 * I would love to save just the ftrace_likely_data pointer, but
44 * this code can also be used by modules. Ugly things can happen
45 * if the module is unloaded, and then we go and read the
46 * pointer. This is slower, but much safer.
52 local_irq_save(flags);
53 cpu = raw_smp_processor_id();
54 if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
59 event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
60 sizeof(*entry), flags, pc);
64 entry = ring_buffer_event_data(event);
66 /* Strip off the path, only save the file */
67 p = f->file + strlen(f->file);
68 while (p >= f->file && *p != '/')
72 strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
73 strncpy(entry->file, p, TRACE_FILE_SIZE);
74 entry->func[TRACE_FUNC_SIZE] = 0;
75 entry->file[TRACE_FILE_SIZE] = 0;
76 entry->line = f->line;
77 entry->correct = val == expect;
79 if (!filter_check_discard(call, entry, buffer, event))
80 ring_buffer_unlock_commit(buffer, event);
83 atomic_dec(&tr->data[cpu]->disabled);
84 local_irq_restore(flags);
88 void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
90 if (!branch_tracing_enabled)
93 probe_likely_condition(f, val, expect);
96 int enable_branch_tracing(struct trace_array *tr)
98 mutex_lock(&branch_tracing_mutex);
101 * Must be seen before enabling. The reader is a condition
102 * where we do not need a matching rmb()
105 branch_tracing_enabled++;
106 mutex_unlock(&branch_tracing_mutex);
111 void disable_branch_tracing(void)
113 mutex_lock(&branch_tracing_mutex);
115 if (!branch_tracing_enabled)
118 branch_tracing_enabled--;
121 mutex_unlock(&branch_tracing_mutex);
124 static void start_branch_trace(struct trace_array *tr)
126 enable_branch_tracing(tr);
129 static void stop_branch_trace(struct trace_array *tr)
131 disable_branch_tracing();
134 static int branch_trace_init(struct trace_array *tr)
136 start_branch_trace(tr);
140 static void branch_trace_reset(struct trace_array *tr)
142 stop_branch_trace(tr);
145 static enum print_line_t trace_branch_print(struct trace_iterator *iter,
148 struct trace_branch *field;
150 trace_assign_type(field, iter->ent);
152 if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n",
153 field->correct ? " ok " : " MISS ",
157 return TRACE_TYPE_PARTIAL_LINE;
159 return TRACE_TYPE_HANDLED;
162 static void branch_print_header(struct seq_file *s)
164 seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT"
165 " FUNC:FILE:LINE\n");
166 seq_puts(s, "# | | | | | "
170 static struct trace_event trace_branch_event = {
171 .type = TRACE_BRANCH,
172 .trace = trace_branch_print,
175 static struct tracer branch_trace __read_mostly =
178 .init = branch_trace_init,
179 .reset = branch_trace_reset,
180 #ifdef CONFIG_FTRACE_SELFTEST
181 .selftest = trace_selftest_startup_branch,
182 #endif /* CONFIG_FTRACE_SELFTEST */
183 .print_header = branch_print_header,
186 __init static int init_branch_tracer(void)
190 ret = register_ftrace_event(&trace_branch_event);
192 printk(KERN_WARNING "Warning: could not register "
196 return register_tracer(&branch_trace);
198 device_initcall(init_branch_tracer);
202 void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
205 #endif /* CONFIG_BRANCH_TRACER */
207 void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
210 * I would love to have a trace point here instead, but the
211 * trace point code is so inundated with unlikely and likely
212 * conditions that the recursive nightmare that exists is too
213 * much to try to get working. At least for now.
215 trace_likely_condition(f, val, expect);
217 /* FIXME: Make this atomic! */
223 EXPORT_SYMBOL(ftrace_likely_update);
225 extern unsigned long __start_annotated_branch_profile[];
226 extern unsigned long __stop_annotated_branch_profile[];
228 static int annotated_branch_stat_headers(struct seq_file *m)
230 seq_printf(m, " correct incorrect %% ");
231 seq_printf(m, " Function "
233 " ------- --------- - "
239 static inline long get_incorrect_percent(struct ftrace_branch_data *p)
244 percent = p->incorrect * 100;
245 percent /= p->correct + p->incorrect;
247 percent = p->incorrect ? 100 : -1;
252 static int branch_stat_show(struct seq_file *m, void *v)
254 struct ftrace_branch_data *p = v;
258 /* Only print the file, not the path */
259 f = p->file + strlen(p->file);
260 while (f >= p->file && *f != '/')
265 * The miss is overlayed on correct, and hit on incorrect.
267 percent = get_incorrect_percent(p);
269 seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect);
271 seq_printf(m, " X ");
273 seq_printf(m, "%3ld ", percent);
274 seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
278 static void *annotated_branch_stat_start(struct tracer_stat *trace)
280 return __start_annotated_branch_profile;
284 annotated_branch_stat_next(void *v, int idx)
286 struct ftrace_branch_data *p = v;
290 if ((void *)p >= (void *)__stop_annotated_branch_profile)
296 static int annotated_branch_stat_cmp(void *p1, void *p2)
298 struct ftrace_branch_data *a = p1;
299 struct ftrace_branch_data *b = p2;
301 long percent_a, percent_b;
303 percent_a = get_incorrect_percent(a);
304 percent_b = get_incorrect_percent(b);
306 if (percent_a < percent_b)
308 if (percent_a > percent_b)
311 if (a->incorrect < b->incorrect)
313 if (a->incorrect > b->incorrect)
317 * Since the above shows worse (incorrect) cases
318 * first, we continue that by showing best (correct)
321 if (a->correct > b->correct)
323 if (a->correct < b->correct)
329 static struct tracer_stat annotated_branch_stats = {
330 .name = "branch_annotated",
331 .stat_start = annotated_branch_stat_start,
332 .stat_next = annotated_branch_stat_next,
333 .stat_cmp = annotated_branch_stat_cmp,
334 .stat_headers = annotated_branch_stat_headers,
335 .stat_show = branch_stat_show
338 __init static int init_annotated_branch_stats(void)
342 ret = register_stat_tracer(&annotated_branch_stats);
344 printk(KERN_WARNING "Warning: could not register "
345 "annotated branches stats\n");
350 fs_initcall(init_annotated_branch_stats);
352 #ifdef CONFIG_PROFILE_ALL_BRANCHES
354 extern unsigned long __start_branch_profile[];
355 extern unsigned long __stop_branch_profile[];
357 static int all_branch_stat_headers(struct seq_file *m)
359 seq_printf(m, " miss hit %% ");
360 seq_printf(m, " Function "
362 " ------- --------- - "
368 static void *all_branch_stat_start(struct tracer_stat *trace)
370 return __start_branch_profile;
374 all_branch_stat_next(void *v, int idx)
376 struct ftrace_branch_data *p = v;
380 if ((void *)p >= (void *)__stop_branch_profile)
386 static struct tracer_stat all_branch_stats = {
387 .name = "branch_all",
388 .stat_start = all_branch_stat_start,
389 .stat_next = all_branch_stat_next,
390 .stat_headers = all_branch_stat_headers,
391 .stat_show = branch_stat_show
394 __init static int all_annotated_branch_stats(void)
398 ret = register_stat_tracer(&all_branch_stats);
400 printk(KERN_WARNING "Warning: could not register "
401 "all branches stats\n");
406 fs_initcall(all_annotated_branch_stats);
407 #endif /* CONFIG_PROFILE_ALL_BRANCHES */