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286 lines
5.0 KiB
286 lines
5.0 KiB
/** |
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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 <[email protected]> |
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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 <linux/workqueue.h> |
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#include <linux/time.h> |
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#include <linux/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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#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX |
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static void switch_worker(struct work_struct *work); |
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static DECLARE_DELAYED_WORK(switch_work, switch_worker); |
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static void start_switch_worker(void) |
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{ |
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if (oprofile_ops.switch_events) |
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schedule_delayed_work(&switch_work, oprofile_time_slice); |
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} |
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static void stop_switch_worker(void) |
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{ |
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cancel_delayed_work_sync(&switch_work); |
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} |
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static void switch_worker(struct work_struct *work) |
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{ |
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if (oprofile_ops.switch_events()) |
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return; |
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atomic_inc(&oprofile_stats.multiplex_counter); |
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start_switch_worker(); |
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} |
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/* User inputs in ms, converts to jiffies */ |
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int oprofile_set_timeout(unsigned long val_msec) |
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{ |
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int err = 0; |
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unsigned long time_slice; |
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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.switch_events) { |
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err = -EINVAL; |
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goto out; |
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} |
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time_slice = msecs_to_jiffies(val_msec); |
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if (time_slice == MAX_JIFFY_OFFSET) { |
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err = -EINVAL; |
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goto out; |
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} |
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oprofile_time_slice = time_slice; |
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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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#else |
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static inline void start_switch_worker(void) { } |
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static inline void stop_switch_worker(void) { } |
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#endif |
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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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start_switch_worker(); |
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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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stop_switch_worker(); |
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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_ulong(unsigned long *addr, unsigned long val) |
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{ |
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int err = -EBUSY; |
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mutex_lock(&start_mutex); |
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if (!oprofile_started) { |
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*addr = val; |
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err = 0; |
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} |
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mutex_unlock(&start_mutex); |
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return err; |
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} |
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static int timer_mode; |
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static int __init oprofile_init(void) |
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{ |
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int err; |
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/* always init architecture to setup backtrace support */ |
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timer_mode = 0; |
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err = oprofile_arch_init(&oprofile_ops); |
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if (!err) { |
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if (!timer && !oprofilefs_register()) |
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return 0; |
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oprofile_arch_exit(); |
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} |
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/* setup timer mode: */ |
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timer_mode = 1; |
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/* no nmi timer mode if oprofile.timer is set */ |
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if (timer || op_nmi_timer_init(&oprofile_ops)) { |
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err = oprofile_timer_init(&oprofile_ops); |
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if (err) |
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return err; |
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} |
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return oprofilefs_register(); |
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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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if (!timer_mode) |
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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 <[email protected]>"); |
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MODULE_DESCRIPTION("OProfile system profiler");
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