217 lines
3.6 KiB
C
217 lines
3.6 KiB
C
/**
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* @file oprof.c
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*
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* @remark Copyright 2002 OProfile authors
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* @remark Read the file COPYING
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*
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* @author John Levon <levon@movementarian.org>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/oprofile.h>
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#include <linux/moduleparam.h>
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#include <asm/mutex.h>
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#include "oprof.h"
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#include "event_buffer.h"
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#include "cpu_buffer.h"
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#include "buffer_sync.h"
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#include "oprofile_stats.h"
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struct oprofile_operations oprofile_ops;
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unsigned long oprofile_started;
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unsigned long oprofile_backtrace_depth;
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static unsigned long is_setup;
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static DEFINE_MUTEX(start_mutex);
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/* timer
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0 - use performance monitoring hardware if available
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1 - use the timer int mechanism regardless
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*/
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static int timer = 0;
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int oprofile_setup(void)
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{
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int err;
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mutex_lock(&start_mutex);
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if ((err = alloc_cpu_buffers()))
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goto out;
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if ((err = alloc_event_buffer()))
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goto out1;
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if (oprofile_ops.setup && (err = oprofile_ops.setup()))
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goto out2;
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/* Note even though this starts part of the
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* profiling overhead, it's necessary to prevent
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* us missing task deaths and eventually oopsing
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* when trying to process the event buffer.
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*/
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if (oprofile_ops.sync_start) {
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int sync_ret = oprofile_ops.sync_start();
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switch (sync_ret) {
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case 0:
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goto post_sync;
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case 1:
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goto do_generic;
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case -1:
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goto out3;
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default:
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goto out3;
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}
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}
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do_generic:
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if ((err = sync_start()))
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goto out3;
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post_sync:
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is_setup = 1;
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mutex_unlock(&start_mutex);
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return 0;
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out3:
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if (oprofile_ops.shutdown)
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oprofile_ops.shutdown();
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out2:
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free_event_buffer();
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out1:
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free_cpu_buffers();
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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/* Actually start profiling (echo 1>/dev/oprofile/enable) */
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int oprofile_start(void)
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{
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int err = -EINVAL;
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mutex_lock(&start_mutex);
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if (!is_setup)
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goto out;
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err = 0;
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if (oprofile_started)
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goto out;
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oprofile_reset_stats();
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if ((err = oprofile_ops.start()))
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goto out;
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oprofile_started = 1;
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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/* echo 0>/dev/oprofile/enable */
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void oprofile_stop(void)
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{
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mutex_lock(&start_mutex);
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if (!oprofile_started)
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goto out;
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oprofile_ops.stop();
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oprofile_started = 0;
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/* wake up the daemon to read what remains */
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wake_up_buffer_waiter();
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out:
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mutex_unlock(&start_mutex);
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}
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void oprofile_shutdown(void)
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{
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mutex_lock(&start_mutex);
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if (oprofile_ops.sync_stop) {
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int sync_ret = oprofile_ops.sync_stop();
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switch (sync_ret) {
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case 0:
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goto post_sync;
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case 1:
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goto do_generic;
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default:
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goto post_sync;
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}
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}
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do_generic:
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sync_stop();
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post_sync:
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if (oprofile_ops.shutdown)
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oprofile_ops.shutdown();
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is_setup = 0;
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free_event_buffer();
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free_cpu_buffers();
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mutex_unlock(&start_mutex);
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}
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int oprofile_set_backtrace(unsigned long val)
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{
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int err = 0;
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mutex_lock(&start_mutex);
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if (oprofile_started) {
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err = -EBUSY;
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goto out;
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}
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if (!oprofile_ops.backtrace) {
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err = -EINVAL;
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goto out;
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}
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oprofile_backtrace_depth = val;
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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static int __init oprofile_init(void)
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{
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int err;
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err = oprofile_arch_init(&oprofile_ops);
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if (err < 0 || timer) {
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printk(KERN_INFO "oprofile: using timer interrupt.\n");
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oprofile_timer_init(&oprofile_ops);
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}
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err = oprofilefs_register();
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if (err)
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oprofile_arch_exit();
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return err;
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}
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static void __exit oprofile_exit(void)
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{
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oprofilefs_unregister();
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oprofile_arch_exit();
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}
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module_init(oprofile_init);
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module_exit(oprofile_exit);
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module_param_named(timer, timer, int, 0644);
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MODULE_PARM_DESC(timer, "force use of timer interrupt");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("John Levon <levon@movementarian.org>");
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MODULE_DESCRIPTION("OProfile system profiler");
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