| | 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/kallsyms.h> |
| | 9 | #include <linux/uaccess.h> |
| | 10 | #include <linux/ftrace.h> |
| | 11 | #include <trace/events/sched.h> |
| | 12 | |
| | 13 | #include "trace.h" |
| | 14 | |
| | 15 | static int sched_ref; |
| | 16 | static DEFINE_MUTEX(sched_register_mutex); |
| | 17 | |
| | 18 | static void |
| | 19 | probe_sched_switch(void *ignore, bool preempt, |
| | 20 | struct task_struct *prev, struct task_struct *next) |
| | 21 | { |
| | 22 | if (unlikely(!sched_ref)) |
| | 23 | return; |
| | 24 | |
| | 25 | tracing_record_cmdline(prev); |
| | 26 | tracing_record_cmdline(next); |
| | 27 | } |
| | 28 | |
| | 29 | static void |
| | 30 | probe_sched_wakeup(void *ignore, struct task_struct *wakee) |
| | 31 | { |
| | 32 | if (unlikely(!sched_ref)) |
| | 33 | return; |
| | 34 | |
| | 35 | tracing_record_cmdline(current); |
| | 36 | } |
| | 37 | |
| | 38 | static int tracing_sched_register(void) |
| | 39 | { |
| | 40 | int ret; |
| | 41 | |
| | 42 | ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL); |
| | 43 | if (ret) { |
| | 44 | pr_info("wakeup trace: Couldn't activate tracepoint" |
| | 45 | " probe to kernel_sched_wakeup\n"); |
| | 46 | return ret; |
| | 47 | } |
| | 48 | |
| | 49 | ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
| | 50 | if (ret) { |
| | 51 | pr_info("wakeup trace: Couldn't activate tracepoint" |
| | 52 | " probe to kernel_sched_wakeup_new\n"); |
| | 53 | goto fail_deprobe; |
| | 54 | } |
| | 55 | |
| | 56 | ret = register_trace_sched_switch(probe_sched_switch, NULL); |
| | 57 | if (ret) { |
| | 58 | pr_info("sched trace: Couldn't activate tracepoint" |
| | 59 | " probe to kernel_sched_switch\n"); |
| | 60 | goto fail_deprobe_wake_new; |
| | 61 | } |
| | 62 | |
| | 63 | return ret; |
| | 64 | fail_deprobe_wake_new: |
| | 65 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
| | 66 | fail_deprobe: |
| | 67 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); |
| | 68 | return ret; |
| | 69 | } |
| | 70 | |
| | 71 | static void tracing_sched_unregister(void) |
| | 72 | { |
| | 73 | unregister_trace_sched_switch(probe_sched_switch, NULL); |
| | 74 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
| | 75 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); |
| | 76 | } |
| | 77 | |
| | 78 | static void tracing_start_sched_switch(void) |
| | 79 | { |
| | 80 | mutex_lock(&sched_register_mutex); |
| | 81 | if (!(sched_ref++)) |
| | 82 | tracing_sched_register(); |
| | 83 | mutex_unlock(&sched_register_mutex); |
| | 84 | } |
| | 85 | |
| | 86 | static void tracing_stop_sched_switch(void) |
| | 87 | { |
| | 88 | mutex_lock(&sched_register_mutex); |
| | 89 | if (!(--sched_ref)) |
| | 90 | tracing_sched_unregister(); |
| | 91 | mutex_unlock(&sched_register_mutex); |
| | 92 | } |
| | 93 | |
| | 94 | void tracing_start_cmdline_record(void) |
| | 95 | { |
| | 96 | tracing_start_sched_switch(); |
| | 97 | } |
| | 98 | |
| | 99 | void tracing_stop_cmdline_record(void) |
| | 100 | { |
| | 101 | tracing_stop_sched_switch(); |
| | 102 | } |
projects / linux-2.6-block.git / blame_incremental