Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1 | /* |
| 2 | * trace context switch |
| 3 | * |
| 4 | * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com> |
| 5 | * |
| 6 | */ |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/fs.h> |
| 9 | #include <linux/debugfs.h> |
| 10 | #include <linux/kallsyms.h> |
| 11 | #include <linux/uaccess.h> |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 12 | #include <linux/ftrace.h> |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 13 | #include <trace/sched.h> |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 14 | |
| 15 | #include "trace.h" |
| 16 | |
| 17 | static struct trace_array *ctx_trace; |
| 18 | static int __read_mostly tracer_enabled; |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 19 | static int sched_ref; |
| 20 | static DEFINE_MUTEX(sched_register_mutex); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 21 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 22 | static void |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 23 | probe_sched_switch(struct rq *__rq, struct task_struct *prev, |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 24 | struct task_struct *next) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 25 | { |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 26 | struct trace_array_cpu *data; |
| 27 | unsigned long flags; |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 28 | int cpu; |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 29 | int pc; |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 30 | |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 31 | if (!sched_ref) |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 32 | return; |
| 33 | |
Steven Rostedt | 41bc814 | 2008-05-22 11:49:22 -0400 | [diff] [blame] | 34 | tracing_record_cmdline(prev); |
| 35 | tracing_record_cmdline(next); |
| 36 | |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 37 | if (!tracer_enabled) |
| 38 | return; |
| 39 | |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 40 | pc = preempt_count(); |
Steven Rostedt | 18cef37 | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 41 | local_irq_save(flags); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 42 | cpu = raw_smp_processor_id(); |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 43 | data = ctx_trace->data[cpu]; |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 44 | |
Steven Rostedt | 3ea2e6d | 2008-10-04 02:01:00 -0400 | [diff] [blame] | 45 | if (likely(!atomic_read(&data->disabled))) |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 46 | tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 47 | |
Steven Rostedt | 18cef37 | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 48 | local_irq_restore(flags); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 49 | } |
| 50 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 51 | static void |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 52 | probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 53 | { |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 54 | struct trace_array_cpu *data; |
| 55 | unsigned long flags; |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 56 | int cpu, pc; |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 57 | |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 58 | if (!likely(tracer_enabled)) |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 59 | return; |
| 60 | |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 61 | pc = preempt_count(); |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 62 | tracing_record_cmdline(current); |
Ingo Molnar | d9af56f | 2008-05-12 21:20:53 +0200 | [diff] [blame] | 63 | |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 64 | local_irq_save(flags); |
| 65 | cpu = raw_smp_processor_id(); |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 66 | data = ctx_trace->data[cpu]; |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 67 | |
Steven Rostedt | 3ea2e6d | 2008-10-04 02:01:00 -0400 | [diff] [blame] | 68 | if (likely(!atomic_read(&data->disabled))) |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 69 | tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, |
Steven Rostedt | 3869705 | 2008-10-01 13:14:09 -0400 | [diff] [blame] | 70 | flags, pc); |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 71 | |
Ingo Molnar | 5742279 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 72 | local_irq_restore(flags); |
| 73 | } |
| 74 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 75 | static void sched_switch_reset(struct trace_array *tr) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 76 | { |
| 77 | int cpu; |
| 78 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 79 | tr->time_start = ftrace_now(tr->cpu); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 80 | |
| 81 | for_each_online_cpu(cpu) |
Steven Rostedt | 3928a8a | 2008-09-29 23:02:41 -0400 | [diff] [blame] | 82 | tracing_reset(tr, cpu); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 83 | } |
| 84 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 85 | static int tracing_sched_register(void) |
| 86 | { |
| 87 | int ret; |
| 88 | |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 89 | ret = register_trace_sched_wakeup(probe_sched_wakeup); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 90 | if (ret) { |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 91 | pr_info("wakeup trace: Couldn't activate tracepoint" |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 92 | " probe to kernel_sched_wakeup\n"); |
| 93 | return ret; |
| 94 | } |
| 95 | |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 96 | ret = register_trace_sched_wakeup_new(probe_sched_wakeup); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 97 | if (ret) { |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 98 | pr_info("wakeup trace: Couldn't activate tracepoint" |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 99 | " probe to kernel_sched_wakeup_new\n"); |
| 100 | goto fail_deprobe; |
| 101 | } |
| 102 | |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 103 | ret = register_trace_sched_switch(probe_sched_switch); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 104 | if (ret) { |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 105 | pr_info("sched trace: Couldn't activate tracepoint" |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 106 | " probe to kernel_sched_schedule\n"); |
| 107 | goto fail_deprobe_wake_new; |
| 108 | } |
| 109 | |
| 110 | return ret; |
| 111 | fail_deprobe_wake_new: |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 112 | unregister_trace_sched_wakeup_new(probe_sched_wakeup); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 113 | fail_deprobe: |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 114 | unregister_trace_sched_wakeup(probe_sched_wakeup); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 115 | return ret; |
| 116 | } |
| 117 | |
| 118 | static void tracing_sched_unregister(void) |
| 119 | { |
Mathieu Desnoyers | b07c3f1 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 120 | unregister_trace_sched_switch(probe_sched_switch); |
| 121 | unregister_trace_sched_wakeup_new(probe_sched_wakeup); |
| 122 | unregister_trace_sched_wakeup(probe_sched_wakeup); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 123 | } |
| 124 | |
Ingo Molnar | f225293 | 2008-05-22 10:37:48 +0200 | [diff] [blame] | 125 | static void tracing_start_sched_switch(void) |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 126 | { |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 127 | mutex_lock(&sched_register_mutex); |
| 128 | if (!(sched_ref++)) { |
| 129 | tracer_enabled = 1; |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 130 | tracing_sched_register(); |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 131 | } |
| 132 | mutex_unlock(&sched_register_mutex); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 133 | } |
| 134 | |
Ingo Molnar | f225293 | 2008-05-22 10:37:48 +0200 | [diff] [blame] | 135 | static void tracing_stop_sched_switch(void) |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 136 | { |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 137 | mutex_lock(&sched_register_mutex); |
| 138 | if (!(--sched_ref)) { |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 139 | tracing_sched_unregister(); |
Frederic Weisbecker | efade6e | 2008-10-31 13:28:58 +0100 | [diff] [blame^] | 140 | tracer_enabled = 0; |
| 141 | } |
| 142 | mutex_unlock(&sched_register_mutex); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 143 | } |
| 144 | |
Steven Rostedt | 41bc814 | 2008-05-22 11:49:22 -0400 | [diff] [blame] | 145 | void tracing_start_cmdline_record(void) |
| 146 | { |
| 147 | tracing_start_sched_switch(); |
| 148 | } |
| 149 | |
| 150 | void tracing_stop_cmdline_record(void) |
| 151 | { |
| 152 | tracing_stop_sched_switch(); |
| 153 | } |
| 154 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 155 | static void start_sched_trace(struct trace_array *tr) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 156 | { |
| 157 | sched_switch_reset(tr); |
Steven Rostedt | 41bc814 | 2008-05-22 11:49:22 -0400 | [diff] [blame] | 158 | tracing_start_cmdline_record(); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 159 | } |
| 160 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 161 | static void stop_sched_trace(struct trace_array *tr) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 162 | { |
Steven Rostedt | 007c05d | 2008-07-10 20:58:09 -0400 | [diff] [blame] | 163 | tracing_stop_cmdline_record(); |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 164 | } |
| 165 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 166 | static void sched_switch_trace_init(struct trace_array *tr) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 167 | { |
| 168 | ctx_trace = tr; |
| 169 | |
| 170 | if (tr->ctrl) |
| 171 | start_sched_trace(tr); |
| 172 | } |
| 173 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 174 | static void sched_switch_trace_reset(struct trace_array *tr) |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 175 | { |
| 176 | if (tr->ctrl) |
| 177 | stop_sched_trace(tr); |
| 178 | } |
| 179 | |
| 180 | static void sched_switch_trace_ctrl_update(struct trace_array *tr) |
| 181 | { |
| 182 | /* When starting a new trace, reset the buffers */ |
| 183 | if (tr->ctrl) |
| 184 | start_sched_trace(tr); |
| 185 | else |
| 186 | stop_sched_trace(tr); |
| 187 | } |
| 188 | |
Frederic Weisbecker | d7ad44b | 2008-10-31 13:20:08 +0100 | [diff] [blame] | 189 | struct tracer sched_switch_trace __read_mostly = |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 190 | { |
| 191 | .name = "sched_switch", |
| 192 | .init = sched_switch_trace_init, |
| 193 | .reset = sched_switch_trace_reset, |
| 194 | .ctrl_update = sched_switch_trace_ctrl_update, |
Steven Rostedt | 60a1177 | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 195 | #ifdef CONFIG_FTRACE_SELFTEST |
| 196 | .selftest = trace_selftest_startup_sched_switch, |
| 197 | #endif |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 198 | }; |
| 199 | |
| 200 | __init static int init_sched_switch_trace(void) |
| 201 | { |
Steven Rostedt | 35e8e30 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 202 | return register_tracer(&sched_switch_trace); |
| 203 | } |
| 204 | device_initcall(init_sched_switch_trace); |