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 trace_array *tr = branch_tracer;
34 struct ring_buffer_event *event;
35 struct trace_branch *entry;
36 unsigned long flags, irq_flags;
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.
50 local_irq_save(flags);
51 cpu = raw_smp_processor_id();
52 if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
55 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
61 entry = ring_buffer_event_data(event);
62 tracing_generic_entry_update(&entry->ent, flags, pc);
63 entry->ent.type = TRACE_BRANCH;
65 /* Strip off the path, only save the file */
66 p = f->file + strlen(f->file);
67 while (p >= f->file && *p != '/')
71 strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
72 strncpy(entry->file, p, TRACE_FILE_SIZE);
73 entry->func[TRACE_FUNC_SIZE] = 0;
74 entry->file[TRACE_FILE_SIZE] = 0;
75 entry->line = f->line;
76 entry->correct = val == expect;
78 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
81 atomic_dec(&tr->data[cpu]->disabled);
82 local_irq_restore(flags);
86 void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
88 if (!branch_tracing_enabled)
91 probe_likely_condition(f, val, expect);
94 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 tracing_reset_online_cpus(tr);
137 start_branch_trace(tr);
141 static void branch_trace_reset(struct trace_array *tr)
143 stop_branch_trace(tr);
147 trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
149 struct print_entry *field;
151 trace_assign_type(field, entry);
153 if (seq_print_ip_sym(s, field->ip, flags))
156 if (trace_seq_printf(s, ": %s", field->buf))
160 return TRACE_TYPE_PARTIAL_LINE;
164 trace_branch_print(struct trace_seq *s, struct trace_entry *entry, int flags)
166 struct trace_branch *field;
168 trace_assign_type(field, entry);
170 if (trace_seq_printf(s, "[%s] %s:%s:%d\n",
171 field->correct ? " ok " : " MISS ",
175 return TRACE_TYPE_PARTIAL_LINE;
181 static struct trace_event trace_branch_event = {
182 .type = TRACE_BRANCH,
183 .trace = trace_branch_print,
184 .latency_trace = trace_branch_print,
185 .raw = trace_nop_print,
186 .hex = trace_nop_print,
187 .binary = trace_nop_print,
190 static struct tracer branch_trace __read_mostly =
193 .init = branch_trace_init,
194 .reset = branch_trace_reset,
195 #ifdef CONFIG_FTRACE_SELFTEST
196 .selftest = trace_selftest_startup_branch,
197 #endif /* CONFIG_FTRACE_SELFTEST */
200 __init static int init_branch_tracer(void)
204 ret = register_ftrace_event(&trace_branch_event);
206 printk(KERN_WARNING "Warning: could not register "
210 return register_tracer(&branch_trace);
212 device_initcall(init_branch_tracer);
216 void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
219 #endif /* CONFIG_BRANCH_TRACER */
221 void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
224 * I would love to have a trace point here instead, but the
225 * trace point code is so inundated with unlikely and likely
226 * conditions that the recursive nightmare that exists is too
227 * much to try to get working. At least for now.
229 trace_likely_condition(f, val, expect);
231 /* FIXME: Make this atomic! */
237 EXPORT_SYMBOL(ftrace_likely_update);
239 extern unsigned long __start_annotated_branch_profile[];
240 extern unsigned long __stop_annotated_branch_profile[];
242 static int annotated_branch_stat_headers(struct seq_file *m)
244 seq_printf(m, " correct incorrect %% ");
245 seq_printf(m, " Function "
247 " ------- --------- - "
253 static inline long get_incorrect_percent(struct ftrace_branch_data *p)
258 percent = p->incorrect * 100;
259 percent /= p->correct + p->incorrect;
261 percent = p->incorrect ? 100 : -1;
266 static int branch_stat_show(struct seq_file *m, void *v)
268 struct ftrace_branch_data *p = v;
272 /* Only print the file, not the path */
273 f = p->file + strlen(p->file);
274 while (f >= p->file && *f != '/')
279 * The miss is overlayed on correct, and hit on incorrect.
281 percent = get_incorrect_percent(p);
283 seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect);
285 seq_printf(m, " X ");
287 seq_printf(m, "%3ld ", percent);
288 seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
292 static void *annotated_branch_stat_start(void)
294 return __start_annotated_branch_profile;
298 annotated_branch_stat_next(void *v, int idx)
300 struct ftrace_branch_data *p = v;
304 if ((void *)p >= (void *)__stop_annotated_branch_profile)
310 static int annotated_branch_stat_cmp(void *p1, void *p2)
312 struct ftrace_branch_data *a = p1;
313 struct ftrace_branch_data *b = p2;
315 long percent_a, percent_b;
317 percent_a = get_incorrect_percent(a);
318 percent_b = get_incorrect_percent(b);
320 if (percent_a < percent_b)
322 if (percent_a > percent_b)
328 static struct tracer_stat annotated_branch_stats = {
329 .name = "branch_annotated",
330 .stat_start = annotated_branch_stat_start,
331 .stat_next = annotated_branch_stat_next,
332 .stat_cmp = annotated_branch_stat_cmp,
333 .stat_headers = annotated_branch_stat_headers,
334 .stat_show = branch_stat_show
337 __init static int init_annotated_branch_stats(void)
341 ret = register_stat_tracer(&annotated_branch_stats);
343 printk(KERN_WARNING "Warning: could not register "
344 "annotated branches stats\n");
349 fs_initcall(init_annotated_branch_stats);
351 #ifdef CONFIG_PROFILE_ALL_BRANCHES
353 extern unsigned long __start_branch_profile[];
354 extern unsigned long __stop_branch_profile[];
356 static int all_branch_stat_headers(struct seq_file *m)
358 seq_printf(m, " miss hit %% ");
359 seq_printf(m, " Function "
361 " ------- --------- - "
367 static void *all_branch_stat_start(void)
369 return __start_branch_profile;
373 all_branch_stat_next(void *v, int idx)
375 struct ftrace_branch_data *p = v;
379 if ((void *)p >= (void *)__stop_branch_profile)
385 static struct tracer_stat all_branch_stats = {
386 .name = "branch_all",
387 .stat_start = all_branch_stat_start,
388 .stat_next = all_branch_stat_next,
389 .stat_headers = all_branch_stat_headers,
390 .stat_show = branch_stat_show
393 __init static int all_annotated_branch_stats(void)
397 ret = register_stat_tracer(&all_branch_stats);
399 printk(KERN_WARNING "Warning: could not register "
400 "all branches stats\n");
405 fs_initcall(all_annotated_branch_stats);
406 #endif /* CONFIG_PROFILE_ALL_BRANCHES */