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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | /** * @file oprof.c * * @remark Copyright 2002 OProfile authors * @remark Read the file COPYING * * @author John Levon <levon@movementarian.org> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/oprofile.h> #include <linux/moduleparam.h> #include <asm/semaphore.h> #include "oprof.h" #include "event_buffer.h" #include "cpu_buffer.h" #include "buffer_sync.h" #include "oprofile_stats.h" struct oprofile_operations oprofile_ops; unsigned long oprofile_started; unsigned long backtrace_depth; static unsigned long is_setup; static DECLARE_MUTEX(start_sem); /* timer 0 - use performance monitoring hardware if available 1 - use the timer int mechanism regardless */ static int timer = 0; int oprofile_setup(void) { int err; down(&start_sem); if ((err = alloc_cpu_buffers())) goto out; if ((err = alloc_event_buffer())) goto out1; if (oprofile_ops.setup && (err = oprofile_ops.setup())) goto out2; /* Note even though this starts part of the * profiling overhead, it's necessary to prevent * us missing task deaths and eventually oopsing * when trying to process the event buffer. */ if ((err = sync_start())) goto out3; is_setup = 1; up(&start_sem); return 0; out3: if (oprofile_ops.shutdown) oprofile_ops.shutdown(); out2: free_event_buffer(); out1: free_cpu_buffers(); out: up(&start_sem); return err; } /* Actually start profiling (echo 1>/dev/oprofile/enable) */ int oprofile_start(void) { int err = -EINVAL; down(&start_sem); if (!is_setup) goto out; err = 0; if (oprofile_started) goto out; oprofile_reset_stats(); if ((err = oprofile_ops.start())) goto out; oprofile_started = 1; out: up(&start_sem); return err; } /* echo 0>/dev/oprofile/enable */ void oprofile_stop(void) { down(&start_sem); if (!oprofile_started) goto out; oprofile_ops.stop(); oprofile_started = 0; /* wake up the daemon to read what remains */ wake_up_buffer_waiter(); out: up(&start_sem); } void oprofile_shutdown(void) { down(&start_sem); sync_stop(); if (oprofile_ops.shutdown) oprofile_ops.shutdown(); is_setup = 0; free_event_buffer(); free_cpu_buffers(); up(&start_sem); } int oprofile_set_backtrace(unsigned long val) { int err = 0; down(&start_sem); if (oprofile_started) { err = -EBUSY; goto out; } if (!oprofile_ops.backtrace) { err = -EINVAL; goto out; } backtrace_depth = val; out: up(&start_sem); return err; } static int __init oprofile_init(void) { int err; err = oprofile_arch_init(&oprofile_ops); if (err < 0 || timer) { printk(KERN_INFO "oprofile: using timer interrupt.\n"); oprofile_timer_init(&oprofile_ops); } err = oprofilefs_register(); if (err) oprofile_arch_exit(); return err; } static void __exit oprofile_exit(void) { oprofilefs_unregister(); oprofile_arch_exit(); } module_init(oprofile_init); module_exit(oprofile_exit); module_param_named(timer, timer, int, 0644); MODULE_PARM_DESC(timer, "force use of timer interrupt"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("John Levon <levon@movementarian.org>"); MODULE_DESCRIPTION("OProfile system profiler"); |