102 lines
2.2 KiB
C
102 lines
2.2 KiB
C
/*
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* trace context switch
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*
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* Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
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*
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*/
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <trace/events/sched.h>
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#include "trace.h"
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static int sched_ref;
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static DEFINE_MUTEX(sched_register_mutex);
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static void
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probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *next)
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{
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if (unlikely(!sched_ref))
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return;
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tracing_record_cmdline(prev);
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tracing_record_cmdline(next);
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}
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static void
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probe_sched_wakeup(void *ignore, struct task_struct *wakee)
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{
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if (unlikely(!sched_ref))
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return;
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tracing_record_cmdline(current);
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}
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static int tracing_sched_register(void)
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{
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int ret;
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ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);
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if (ret) {
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pr_info("wakeup trace: Couldn't activate tracepoint"
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" probe to kernel_sched_wakeup\n");
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return ret;
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}
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ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
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if (ret) {
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pr_info("wakeup trace: Couldn't activate tracepoint"
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" probe to kernel_sched_wakeup_new\n");
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goto fail_deprobe;
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}
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ret = register_trace_sched_switch(probe_sched_switch, NULL);
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if (ret) {
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pr_info("sched trace: Couldn't activate tracepoint"
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" probe to kernel_sched_switch\n");
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goto fail_deprobe_wake_new;
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}
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return ret;
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fail_deprobe_wake_new:
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unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
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fail_deprobe:
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unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
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return ret;
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}
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static void tracing_sched_unregister(void)
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{
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unregister_trace_sched_switch(probe_sched_switch, NULL);
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unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
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unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
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}
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static void tracing_start_sched_switch(void)
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{
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mutex_lock(&sched_register_mutex);
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if (!(sched_ref++))
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tracing_sched_register();
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mutex_unlock(&sched_register_mutex);
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}
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static void tracing_stop_sched_switch(void)
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{
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mutex_lock(&sched_register_mutex);
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if (!(--sched_ref))
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tracing_sched_unregister();
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mutex_unlock(&sched_register_mutex);
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}
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void tracing_start_cmdline_record(void)
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{
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tracing_start_sched_switch();
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}
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void tracing_stop_cmdline_record(void)
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{
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tracing_stop_sched_switch();
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}
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