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authorDavid S. Miller <davem@davemloft.net>2010-05-19 02:01:55 -0400
committerDavid S. Miller <davem@davemloft.net>2010-05-19 02:01:55 -0400
commit2ec8c6bb5d8f3a62a79f463525054bae1e3d4487 (patch)
treefa7f8400ac685fb52e96f64997c7c682fc2aa021 /kernel/trace/trace_irqsoff.c
parent7b39f90fabcf9e2af0cd79d0a60440d821e22b56 (diff)
parent537b60d17894b7c19a6060feae40299d7109d6e7 (diff)
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts: include/linux/mod_devicetable.h scripts/mod/file2alias.c
Diffstat (limited to 'kernel/trace/trace_irqsoff.c')
-rw-r--r--kernel/trace/trace_irqsoff.c271
1 files changed, 260 insertions, 11 deletions
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 2974bc7538c7..6fd486e0cef4 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -34,6 +34,9 @@ static int trace_type __read_mostly;
34 34
35static int save_lat_flag; 35static int save_lat_flag;
36 36
37static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
38static int start_irqsoff_tracer(struct trace_array *tr, int graph);
39
37#ifdef CONFIG_PREEMPT_TRACER 40#ifdef CONFIG_PREEMPT_TRACER
38static inline int 41static inline int
39preempt_trace(void) 42preempt_trace(void)
@@ -55,6 +58,23 @@ irq_trace(void)
55# define irq_trace() (0) 58# define irq_trace() (0)
56#endif 59#endif
57 60
61#define TRACE_DISPLAY_GRAPH 1
62
63static struct tracer_opt trace_opts[] = {
64#ifdef CONFIG_FUNCTION_GRAPH_TRACER
65 /* display latency trace as call graph */
66 { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) },
67#endif
68 { } /* Empty entry */
69};
70
71static struct tracer_flags tracer_flags = {
72 .val = 0,
73 .opts = trace_opts,
74};
75
76#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH)
77
58/* 78/*
59 * Sequence count - we record it when starting a measurement and 79 * Sequence count - we record it when starting a measurement and
60 * skip the latency if the sequence has changed - some other section 80 * skip the latency if the sequence has changed - some other section
@@ -108,6 +128,202 @@ static struct ftrace_ops trace_ops __read_mostly =
108}; 128};
109#endif /* CONFIG_FUNCTION_TRACER */ 129#endif /* CONFIG_FUNCTION_TRACER */
110 130
131#ifdef CONFIG_FUNCTION_GRAPH_TRACER
132static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
133{
134 int cpu;
135
136 if (!(bit & TRACE_DISPLAY_GRAPH))
137 return -EINVAL;
138
139 if (!(is_graph() ^ set))
140 return 0;
141
142 stop_irqsoff_tracer(irqsoff_trace, !set);
143
144 for_each_possible_cpu(cpu)
145 per_cpu(tracing_cpu, cpu) = 0;
146
147 tracing_max_latency = 0;
148 tracing_reset_online_cpus(irqsoff_trace);
149
150 return start_irqsoff_tracer(irqsoff_trace, set);
151}
152
153static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
154{
155 struct trace_array *tr = irqsoff_trace;
156 struct trace_array_cpu *data;
157 unsigned long flags;
158 long disabled;
159 int ret;
160 int cpu;
161 int pc;
162
163 cpu = raw_smp_processor_id();
164 if (likely(!per_cpu(tracing_cpu, cpu)))
165 return 0;
166
167 local_save_flags(flags);
168 /* slight chance to get a false positive on tracing_cpu */
169 if (!irqs_disabled_flags(flags))
170 return 0;
171
172 data = tr->data[cpu];
173 disabled = atomic_inc_return(&data->disabled);
174
175 if (likely(disabled == 1)) {
176 pc = preempt_count();
177 ret = __trace_graph_entry(tr, trace, flags, pc);
178 } else
179 ret = 0;
180
181 atomic_dec(&data->disabled);
182 return ret;
183}
184
185static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
186{
187 struct trace_array *tr = irqsoff_trace;
188 struct trace_array_cpu *data;
189 unsigned long flags;
190 long disabled;
191 int cpu;
192 int pc;
193
194 cpu = raw_smp_processor_id();
195 if (likely(!per_cpu(tracing_cpu, cpu)))
196 return;
197
198 local_save_flags(flags);
199 /* slight chance to get a false positive on tracing_cpu */
200 if (!irqs_disabled_flags(flags))
201 return;
202
203 data = tr->data[cpu];
204 disabled = atomic_inc_return(&data->disabled);
205
206 if (likely(disabled == 1)) {
207 pc = preempt_count();
208 __trace_graph_return(tr, trace, flags, pc);
209 }
210
211 atomic_dec(&data->disabled);
212}
213
214static void irqsoff_trace_open(struct trace_iterator *iter)
215{
216 if (is_graph())
217 graph_trace_open(iter);
218
219}
220
221static void irqsoff_trace_close(struct trace_iterator *iter)
222{
223 if (iter->private)
224 graph_trace_close(iter);
225}
226
227#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
228 TRACE_GRAPH_PRINT_PROC)
229
230static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
231{
232 u32 flags = GRAPH_TRACER_FLAGS;
233
234 if (trace_flags & TRACE_ITER_LATENCY_FMT)
235 flags |= TRACE_GRAPH_PRINT_DURATION;
236 else
237 flags |= TRACE_GRAPH_PRINT_ABS_TIME;
238
239 /*
240 * In graph mode call the graph tracer output function,
241 * otherwise go with the TRACE_FN event handler
242 */
243 if (is_graph())
244 return print_graph_function_flags(iter, flags);
245
246 return TRACE_TYPE_UNHANDLED;
247}
248
249static void irqsoff_print_header(struct seq_file *s)
250{
251 if (is_graph()) {
252 struct trace_iterator *iter = s->private;
253 u32 flags = GRAPH_TRACER_FLAGS;
254
255 if (trace_flags & TRACE_ITER_LATENCY_FMT) {
256 /* print nothing if the buffers are empty */
257 if (trace_empty(iter))
258 return;
259
260 print_trace_header(s, iter);
261 flags |= TRACE_GRAPH_PRINT_DURATION;
262 } else
263 flags |= TRACE_GRAPH_PRINT_ABS_TIME;
264
265 print_graph_headers_flags(s, flags);
266 } else
267 trace_default_header(s);
268}
269
270static void
271trace_graph_function(struct trace_array *tr,
272 unsigned long ip, unsigned long flags, int pc)
273{
274 u64 time = trace_clock_local();
275 struct ftrace_graph_ent ent = {
276 .func = ip,
277 .depth = 0,
278 };
279 struct ftrace_graph_ret ret = {
280 .func = ip,
281 .depth = 0,
282 .calltime = time,
283 .rettime = time,
284 };
285
286 __trace_graph_entry(tr, &ent, flags, pc);
287 __trace_graph_return(tr, &ret, flags, pc);
288}
289
290static void
291__trace_function(struct trace_array *tr,
292 unsigned long ip, unsigned long parent_ip,
293 unsigned long flags, int pc)
294{
295 if (!is_graph())
296 trace_function(tr, ip, parent_ip, flags, pc);
297 else {
298 trace_graph_function(tr, parent_ip, flags, pc);
299 trace_graph_function(tr, ip, flags, pc);
300 }
301}
302
303#else
304#define __trace_function trace_function
305
306static int irqsoff_set_flag(u32 old_flags, u32 bit, int set)
307{
308 return -EINVAL;
309}
310
311static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
312{
313 return -1;
314}
315
316static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
317{
318 return TRACE_TYPE_UNHANDLED;
319}
320
321static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
322static void irqsoff_print_header(struct seq_file *s) { }
323static void irqsoff_trace_open(struct trace_iterator *iter) { }
324static void irqsoff_trace_close(struct trace_iterator *iter) { }
325#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
326
111/* 327/*
112 * Should this new latency be reported/recorded? 328 * Should this new latency be reported/recorded?
113 */ 329 */
@@ -150,7 +366,7 @@ check_critical_timing(struct trace_array *tr,
150 if (!report_latency(delta)) 366 if (!report_latency(delta))
151 goto out_unlock; 367 goto out_unlock;
152 368
153 trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); 369 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
154 /* Skip 5 functions to get to the irq/preempt enable function */ 370 /* Skip 5 functions to get to the irq/preempt enable function */
155 __trace_stack(tr, flags, 5, pc); 371 __trace_stack(tr, flags, 5, pc);
156 372
@@ -172,7 +388,7 @@ out_unlock:
172out: 388out:
173 data->critical_sequence = max_sequence; 389 data->critical_sequence = max_sequence;
174 data->preempt_timestamp = ftrace_now(cpu); 390 data->preempt_timestamp = ftrace_now(cpu);
175 trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); 391 __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
176} 392}
177 393
178static inline void 394static inline void
@@ -204,7 +420,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
204 420
205 local_save_flags(flags); 421 local_save_flags(flags);
206 422
207 trace_function(tr, ip, parent_ip, flags, preempt_count()); 423 __trace_function(tr, ip, parent_ip, flags, preempt_count());
208 424
209 per_cpu(tracing_cpu, cpu) = 1; 425 per_cpu(tracing_cpu, cpu) = 1;
210 426
@@ -238,7 +454,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
238 atomic_inc(&data->disabled); 454 atomic_inc(&data->disabled);
239 455
240 local_save_flags(flags); 456 local_save_flags(flags);
241 trace_function(tr, ip, parent_ip, flags, preempt_count()); 457 __trace_function(tr, ip, parent_ip, flags, preempt_count());
242 check_critical_timing(tr, data, parent_ip ? : ip, cpu); 458 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
243 data->critical_start = 0; 459 data->critical_start = 0;
244 atomic_dec(&data->disabled); 460 atomic_dec(&data->disabled);
@@ -347,19 +563,32 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
347} 563}
348#endif /* CONFIG_PREEMPT_TRACER */ 564#endif /* CONFIG_PREEMPT_TRACER */
349 565
350static void start_irqsoff_tracer(struct trace_array *tr) 566static int start_irqsoff_tracer(struct trace_array *tr, int graph)
351{ 567{
352 register_ftrace_function(&trace_ops); 568 int ret = 0;
353 if (tracing_is_enabled()) 569
570 if (!graph)
571 ret = register_ftrace_function(&trace_ops);
572 else
573 ret = register_ftrace_graph(&irqsoff_graph_return,
574 &irqsoff_graph_entry);
575
576 if (!ret && tracing_is_enabled())
354 tracer_enabled = 1; 577 tracer_enabled = 1;
355 else 578 else
356 tracer_enabled = 0; 579 tracer_enabled = 0;
580
581 return ret;
357} 582}
358 583
359static void stop_irqsoff_tracer(struct trace_array *tr) 584static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
360{ 585{
361 tracer_enabled = 0; 586 tracer_enabled = 0;
362 unregister_ftrace_function(&trace_ops); 587
588 if (!graph)
589 unregister_ftrace_function(&trace_ops);
590 else
591 unregister_ftrace_graph();
363} 592}
364 593
365static void __irqsoff_tracer_init(struct trace_array *tr) 594static void __irqsoff_tracer_init(struct trace_array *tr)
@@ -372,12 +601,14 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
372 /* make sure that the tracer is visible */ 601 /* make sure that the tracer is visible */
373 smp_wmb(); 602 smp_wmb();
374 tracing_reset_online_cpus(tr); 603 tracing_reset_online_cpus(tr);
375 start_irqsoff_tracer(tr); 604
605 if (start_irqsoff_tracer(tr, is_graph()))
606 printk(KERN_ERR "failed to start irqsoff tracer\n");
376} 607}
377 608
378static void irqsoff_tracer_reset(struct trace_array *tr) 609static void irqsoff_tracer_reset(struct trace_array *tr)
379{ 610{
380 stop_irqsoff_tracer(tr); 611 stop_irqsoff_tracer(tr, is_graph());
381 612
382 if (!save_lat_flag) 613 if (!save_lat_flag)
383 trace_flags &= ~TRACE_ITER_LATENCY_FMT; 614 trace_flags &= ~TRACE_ITER_LATENCY_FMT;
@@ -409,9 +640,15 @@ static struct tracer irqsoff_tracer __read_mostly =
409 .start = irqsoff_tracer_start, 640 .start = irqsoff_tracer_start,
410 .stop = irqsoff_tracer_stop, 641 .stop = irqsoff_tracer_stop,
411 .print_max = 1, 642 .print_max = 1,
643 .print_header = irqsoff_print_header,
644 .print_line = irqsoff_print_line,
645 .flags = &tracer_flags,
646 .set_flag = irqsoff_set_flag,
412#ifdef CONFIG_FTRACE_SELFTEST 647#ifdef CONFIG_FTRACE_SELFTEST
413 .selftest = trace_selftest_startup_irqsoff, 648 .selftest = trace_selftest_startup_irqsoff,
414#endif 649#endif
650 .open = irqsoff_trace_open,
651 .close = irqsoff_trace_close,
415}; 652};
416# define register_irqsoff(trace) register_tracer(&trace) 653# define register_irqsoff(trace) register_tracer(&trace)
417#else 654#else
@@ -435,9 +672,15 @@ static struct tracer preemptoff_tracer __read_mostly =
435 .start = irqsoff_tracer_start, 672 .start = irqsoff_tracer_start,
436 .stop = irqsoff_tracer_stop, 673 .stop = irqsoff_tracer_stop,
437 .print_max = 1, 674 .print_max = 1,
675 .print_header = irqsoff_print_header,
676 .print_line = irqsoff_print_line,
677 .flags = &tracer_flags,
678 .set_flag = irqsoff_set_flag,
438#ifdef CONFIG_FTRACE_SELFTEST 679#ifdef CONFIG_FTRACE_SELFTEST
439 .selftest = trace_selftest_startup_preemptoff, 680 .selftest = trace_selftest_startup_preemptoff,
440#endif 681#endif
682 .open = irqsoff_trace_open,
683 .close = irqsoff_trace_close,
441}; 684};
442# define register_preemptoff(trace) register_tracer(&trace) 685# define register_preemptoff(trace) register_tracer(&trace)
443#else 686#else
@@ -463,9 +706,15 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
463 .start = irqsoff_tracer_start, 706 .start = irqsoff_tracer_start,
464 .stop = irqsoff_tracer_stop, 707 .stop = irqsoff_tracer_stop,
465 .print_max = 1, 708 .print_max = 1,
709 .print_header = irqsoff_print_header,
710 .print_line = irqsoff_print_line,
711 .flags = &tracer_flags,
712 .set_flag = irqsoff_set_flag,
466#ifdef CONFIG_FTRACE_SELFTEST 713#ifdef CONFIG_FTRACE_SELFTEST
467 .selftest = trace_selftest_startup_preemptirqsoff, 714 .selftest = trace_selftest_startup_preemptirqsoff,
468#endif 715#endif
716 .open = irqsoff_trace_open,
717 .close = irqsoff_trace_close,
469}; 718};
470 719
471# define register_preemptirqsoff(trace) register_tracer(&trace) 720# define register_preemptirqsoff(trace) register_tracer(&trace)