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authorFrederic Weisbecker <fweisbec@gmail.com>2008-11-15 23:57:26 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-16 01:55:23 -0500
commit1c80025a49855b12fa09bb6db71820e3367b1369 (patch)
tree063fe72ed9bb3410c3293c83a7882cecc46e7410 /kernel
parente6e7a65aabdb696cf05a56cfd495c49a11fd4cde (diff)
tracing/ftrace: change the type of the init() callback
Impact: extend the ->init() method with the ability to fail This bring a way to know if the initialization of a tracer successed. A tracer must return 0 on success and a traditional error (ie: -ENOMEM) if it fails. If a tracer fails to init, it is free to print a detailed warn. The tracing api will not and switch to a new tracer will just return the error from the init callback. Note: this will be used for the return tracer. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c7
-rw-r--r--kernel/trace/trace.h3
-rw-r--r--kernel/trace/trace_boot.c3
-rw-r--r--kernel/trace/trace_branch.c3
-rw-r--r--kernel/trace/trace_functions.c3
-rw-r--r--kernel/trace/trace_functions_return.c3
-rw-r--r--kernel/trace/trace_irqsoff.c9
-rw-r--r--kernel/trace/trace_mmiotrace.c3
-rw-r--r--kernel/trace/trace_nop.c3
-rw-r--r--kernel/trace/trace_sched_switch.c3
-rw-r--r--kernel/trace/trace_sched_wakeup.c3
-rw-r--r--kernel/trace/trace_selftest.c66
-rw-r--r--kernel/trace/trace_sysprof.c3
13 files changed, 88 insertions, 24 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 80898f4870cc..396fda034e3f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2638,8 +2638,11 @@ static int tracing_set_tracer(char *buf)
2638 current_trace->reset(tr); 2638 current_trace->reset(tr);
2639 2639
2640 current_trace = t; 2640 current_trace = t;
2641 if (t->init) 2641 if (t->init) {
2642 t->init(tr); 2642 ret = t->init(tr);
2643 if (ret)
2644 goto out;
2645 }
2643 2646
2644 trace_branch_enable(tr); 2647 trace_branch_enable(tr);
2645 out: 2648 out:
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 790ea8c0e1f3..cdbd5cc22be8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -264,7 +264,8 @@ enum print_line_t {
264 */ 264 */
265struct tracer { 265struct tracer {
266 const char *name; 266 const char *name;
267 void (*init)(struct trace_array *tr); 267 /* Your tracer should raise a warning if init fails */
268 int (*init)(struct trace_array *tr);
268 void (*reset)(struct trace_array *tr); 269 void (*reset)(struct trace_array *tr);
269 void (*start)(struct trace_array *tr); 270 void (*start)(struct trace_array *tr);
270 void (*stop)(struct trace_array *tr); 271 void (*stop)(struct trace_array *tr);
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index cb333b7fd113..a4fa2c57e34e 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -47,7 +47,7 @@ static void reset_boot_trace(struct trace_array *tr)
47 tracing_reset(tr, cpu); 47 tracing_reset(tr, cpu);
48} 48}
49 49
50static void boot_trace_init(struct trace_array *tr) 50static int boot_trace_init(struct trace_array *tr)
51{ 51{
52 int cpu; 52 int cpu;
53 boot_trace = tr; 53 boot_trace = tr;
@@ -56,6 +56,7 @@ static void boot_trace_init(struct trace_array *tr)
56 tracing_reset(tr, cpu); 56 tracing_reset(tr, cpu);
57 57
58 tracing_sched_switch_assign_trace(tr); 58 tracing_sched_switch_assign_trace(tr);
59 return 0;
59} 60}
60 61
61static enum print_line_t 62static enum print_line_t
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 85265553918f..44bd39539d61 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -125,7 +125,7 @@ static void stop_branch_trace(struct trace_array *tr)
125 disable_branch_tracing(); 125 disable_branch_tracing();
126} 126}
127 127
128static void branch_trace_init(struct trace_array *tr) 128static int branch_trace_init(struct trace_array *tr)
129{ 129{
130 int cpu; 130 int cpu;
131 131
@@ -133,6 +133,7 @@ static void branch_trace_init(struct trace_array *tr)
133 tracing_reset(tr, cpu); 133 tracing_reset(tr, cpu);
134 134
135 start_branch_trace(tr); 135 start_branch_trace(tr);
136 return 0;
136} 137}
137 138
138static void branch_trace_reset(struct trace_array *tr) 139static void branch_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8693b7a0a5b2..e74f6d0a3216 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -42,9 +42,10 @@ static void stop_function_trace(struct trace_array *tr)
42 tracing_stop_cmdline_record(); 42 tracing_stop_cmdline_record();
43} 43}
44 44
45static void function_trace_init(struct trace_array *tr) 45static int function_trace_init(struct trace_array *tr)
46{ 46{
47 start_function_trace(tr); 47 start_function_trace(tr);
48 return 0;
48} 49}
49 50
50static void function_trace_reset(struct trace_array *tr) 51static void function_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c
index 7680b21537dd..61185f756a13 100644
--- a/kernel/trace/trace_functions_return.c
+++ b/kernel/trace/trace_functions_return.c
@@ -24,13 +24,14 @@ static void stop_return_trace(struct trace_array *tr)
24 unregister_ftrace_return(); 24 unregister_ftrace_return();
25} 25}
26 26
27static void return_trace_init(struct trace_array *tr) 27static int return_trace_init(struct trace_array *tr)
28{ 28{
29 int cpu; 29 int cpu;
30 for_each_online_cpu(cpu) 30 for_each_online_cpu(cpu)
31 tracing_reset(tr, cpu); 31 tracing_reset(tr, cpu);
32 32
33 start_return_trace(tr); 33 start_return_trace(tr);
34 return 0;
34} 35}
35 36
36static void return_trace_reset(struct trace_array *tr) 37static void return_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index d919d4eaa7cc..7c2e326bbc8b 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -416,11 +416,12 @@ static void irqsoff_tracer_close(struct trace_iterator *iter)
416} 416}
417 417
418#ifdef CONFIG_IRQSOFF_TRACER 418#ifdef CONFIG_IRQSOFF_TRACER
419static void irqsoff_tracer_init(struct trace_array *tr) 419static int irqsoff_tracer_init(struct trace_array *tr)
420{ 420{
421 trace_type = TRACER_IRQS_OFF; 421 trace_type = TRACER_IRQS_OFF;
422 422
423 __irqsoff_tracer_init(tr); 423 __irqsoff_tracer_init(tr);
424 return 0;
424} 425}
425static struct tracer irqsoff_tracer __read_mostly = 426static struct tracer irqsoff_tracer __read_mostly =
426{ 427{
@@ -442,11 +443,12 @@ static struct tracer irqsoff_tracer __read_mostly =
442#endif 443#endif
443 444
444#ifdef CONFIG_PREEMPT_TRACER 445#ifdef CONFIG_PREEMPT_TRACER
445static void preemptoff_tracer_init(struct trace_array *tr) 446static int preemptoff_tracer_init(struct trace_array *tr)
446{ 447{
447 trace_type = TRACER_PREEMPT_OFF; 448 trace_type = TRACER_PREEMPT_OFF;
448 449
449 __irqsoff_tracer_init(tr); 450 __irqsoff_tracer_init(tr);
451 return 0;
450} 452}
451 453
452static struct tracer preemptoff_tracer __read_mostly = 454static struct tracer preemptoff_tracer __read_mostly =
@@ -471,11 +473,12 @@ static struct tracer preemptoff_tracer __read_mostly =
471#if defined(CONFIG_IRQSOFF_TRACER) && \ 473#if defined(CONFIG_IRQSOFF_TRACER) && \
472 defined(CONFIG_PREEMPT_TRACER) 474 defined(CONFIG_PREEMPT_TRACER)
473 475
474static void preemptirqsoff_tracer_init(struct trace_array *tr) 476static int preemptirqsoff_tracer_init(struct trace_array *tr)
475{ 477{
476 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; 478 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
477 479
478 __irqsoff_tracer_init(tr); 480 __irqsoff_tracer_init(tr);
481 return 0;
479} 482}
480 483
481static struct tracer preemptirqsoff_tracer __read_mostly = 484static struct tracer preemptirqsoff_tracer __read_mostly =
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 51bcf370215e..433d650eda9f 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -30,13 +30,14 @@ static void mmio_reset_data(struct trace_array *tr)
30 tracing_reset(tr, cpu); 30 tracing_reset(tr, cpu);
31} 31}
32 32
33static void mmio_trace_init(struct trace_array *tr) 33static int mmio_trace_init(struct trace_array *tr)
34{ 34{
35 pr_debug("in %s\n", __func__); 35 pr_debug("in %s\n", __func__);
36 mmio_trace_array = tr; 36 mmio_trace_array = tr;
37 37
38 mmio_reset_data(tr); 38 mmio_reset_data(tr);
39 enable_mmiotrace(); 39 enable_mmiotrace();
40 return 0;
40} 41}
41 42
42static void mmio_trace_reset(struct trace_array *tr) 43static void mmio_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 2ef1d227e7d8..0e77415caed3 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -24,7 +24,7 @@ static void stop_nop_trace(struct trace_array *tr)
24 /* Nothing to do! */ 24 /* Nothing to do! */
25} 25}
26 26
27static void nop_trace_init(struct trace_array *tr) 27static int nop_trace_init(struct trace_array *tr)
28{ 28{
29 int cpu; 29 int cpu;
30 ctx_trace = tr; 30 ctx_trace = tr;
@@ -33,6 +33,7 @@ static void nop_trace_init(struct trace_array *tr)
33 tracing_reset(tr, cpu); 33 tracing_reset(tr, cpu);
34 34
35 start_nop_trace(tr); 35 start_nop_trace(tr);
36 return 0;
36} 37}
37 38
38static void nop_trace_reset(struct trace_array *tr) 39static void nop_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index be35bdfe2e38..863390557b44 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -206,10 +206,11 @@ static void stop_sched_trace(struct trace_array *tr)
206 tracing_stop_sched_switch_record(); 206 tracing_stop_sched_switch_record();
207} 207}
208 208
209static void sched_switch_trace_init(struct trace_array *tr) 209static int sched_switch_trace_init(struct trace_array *tr)
210{ 210{
211 ctx_trace = tr; 211 ctx_trace = tr;
212 start_sched_trace(tr); 212 start_sched_trace(tr);
213 return 0;
213} 214}
214 215
215static void sched_switch_trace_reset(struct trace_array *tr) 216static void sched_switch_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 983f2b1478c9..0067b49746c1 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -331,10 +331,11 @@ static void stop_wakeup_tracer(struct trace_array *tr)
331 unregister_trace_sched_wakeup(probe_wakeup); 331 unregister_trace_sched_wakeup(probe_wakeup);
332} 332}
333 333
334static void wakeup_tracer_init(struct trace_array *tr) 334static int wakeup_tracer_init(struct trace_array *tr)
335{ 335{
336 wakeup_trace = tr; 336 wakeup_trace = tr;
337 start_wakeup_tracer(tr); 337 start_wakeup_tracer(tr);
338 return 0;
338} 339}
339 340
340static void wakeup_tracer_reset(struct trace_array *tr) 341static void wakeup_tracer_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 5cb64ea061b5..88c8eb70f54a 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -71,6 +71,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
71 return ret; 71 return ret;
72} 72}
73 73
74static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
75{
76 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
77 trace->name, init_ret);
78}
74#ifdef CONFIG_FUNCTION_TRACER 79#ifdef CONFIG_FUNCTION_TRACER
75 80
76#ifdef CONFIG_DYNAMIC_FTRACE 81#ifdef CONFIG_DYNAMIC_FTRACE
@@ -111,7 +116,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
111 ftrace_set_filter(func_name, strlen(func_name), 1); 116 ftrace_set_filter(func_name, strlen(func_name), 1);
112 117
113 /* enable tracing */ 118 /* enable tracing */
114 trace->init(tr); 119 ret = trace->init(tr);
120 if (ret) {
121 warn_failed_init_tracer(trace, ret);
122 goto out;
123 }
115 124
116 /* Sleep for a 1/10 of a second */ 125 /* Sleep for a 1/10 of a second */
117 msleep(100); 126 msleep(100);
@@ -181,7 +190,12 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
181 ftrace_enabled = 1; 190 ftrace_enabled = 1;
182 tracer_enabled = 1; 191 tracer_enabled = 1;
183 192
184 trace->init(tr); 193 ret = trace->init(tr);
194 if (ret) {
195 warn_failed_init_tracer(trace, ret);
196 goto out;
197 }
198
185 /* Sleep for a 1/10 of a second */ 199 /* Sleep for a 1/10 of a second */
186 msleep(100); 200 msleep(100);
187 /* stop the tracing. */ 201 /* stop the tracing. */
@@ -223,7 +237,12 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
223 int ret; 237 int ret;
224 238
225 /* start the tracing */ 239 /* start the tracing */
226 trace->init(tr); 240 ret = trace->init(tr);
241 if (ret) {
242 warn_failed_init_tracer(trace, ret);
243 return ret;
244 }
245
227 /* reset the max latency */ 246 /* reset the max latency */
228 tracing_max_latency = 0; 247 tracing_max_latency = 0;
229 /* disable interrupts for a bit */ 248 /* disable interrupts for a bit */
@@ -272,7 +291,12 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
272 } 291 }
273 292
274 /* start the tracing */ 293 /* start the tracing */
275 trace->init(tr); 294 ret = trace->init(tr);
295 if (ret) {
296 warn_failed_init_tracer(trace, ret);
297 return ret;
298 }
299
276 /* reset the max latency */ 300 /* reset the max latency */
277 tracing_max_latency = 0; 301 tracing_max_latency = 0;
278 /* disable preemption for a bit */ 302 /* disable preemption for a bit */
@@ -321,7 +345,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
321 } 345 }
322 346
323 /* start the tracing */ 347 /* start the tracing */
324 trace->init(tr); 348 ret = trace->init(tr);
349 if (ret) {
350 warn_failed_init_tracer(trace, ret);
351 goto out;
352 }
325 353
326 /* reset the max latency */ 354 /* reset the max latency */
327 tracing_max_latency = 0; 355 tracing_max_latency = 0;
@@ -449,7 +477,12 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
449 wait_for_completion(&isrt); 477 wait_for_completion(&isrt);
450 478
451 /* start the tracing */ 479 /* start the tracing */
452 trace->init(tr); 480 ret = trace->init(tr);
481 if (ret) {
482 warn_failed_init_tracer(trace, ret);
483 return ret;
484 }
485
453 /* reset the max latency */ 486 /* reset the max latency */
454 tracing_max_latency = 0; 487 tracing_max_latency = 0;
455 488
@@ -505,7 +538,12 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
505 int ret; 538 int ret;
506 539
507 /* start the tracing */ 540 /* start the tracing */
508 trace->init(tr); 541 ret = trace->init(tr);
542 if (ret) {
543 warn_failed_init_tracer(trace, ret);
544 return ret;
545 }
546
509 /* Sleep for a 1/10 of a second */ 547 /* Sleep for a 1/10 of a second */
510 msleep(100); 548 msleep(100);
511 /* stop the tracing. */ 549 /* stop the tracing. */
@@ -532,7 +570,12 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
532 int ret; 570 int ret;
533 571
534 /* start the tracing */ 572 /* start the tracing */
535 trace->init(tr); 573 ret = trace->init(tr);
574 if (ret) {
575 warn_failed_init_tracer(trace, ret);
576 return 0;
577 }
578
536 /* Sleep for a 1/10 of a second */ 579 /* Sleep for a 1/10 of a second */
537 msleep(100); 580 msleep(100);
538 /* stop the tracing. */ 581 /* stop the tracing. */
@@ -554,7 +597,12 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
554 int ret; 597 int ret;
555 598
556 /* start the tracing */ 599 /* start the tracing */
557 trace->init(tr); 600 ret = trace->init(tr);
601 if (ret) {
602 warn_failed_init_tracer(trace, ret);
603 return ret;
604 }
605
558 /* Sleep for a 1/10 of a second */ 606 /* Sleep for a 1/10 of a second */
559 msleep(100); 607 msleep(100);
560 /* stop the tracing. */ 608 /* stop the tracing. */
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 05f753422aea..54960edb96d0 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -261,11 +261,12 @@ static void stop_stack_trace(struct trace_array *tr)
261 mutex_unlock(&sample_timer_lock); 261 mutex_unlock(&sample_timer_lock);
262} 262}
263 263
264static void stack_trace_init(struct trace_array *tr) 264static int stack_trace_init(struct trace_array *tr)
265{ 265{
266 sysprof_trace = tr; 266 sysprof_trace = tr;
267 267
268 start_stack_trace(tr); 268 start_stack_trace(tr);
269 return 0;
269} 270}
270 271
271static void stack_trace_reset(struct trace_array *tr) 272static void stack_trace_reset(struct trace_array *tr)