diff options
Diffstat (limited to 'drivers/oprofile/oprof.c')
| -rw-r--r-- | drivers/oprofile/oprof.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c new file mode 100644 index 000000000..ed2c3ec07 --- /dev/null +++ b/drivers/oprofile/oprof.c @@ -0,0 +1,286 @@ +/** + * @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 <linux/workqueue.h> +#include <linux/time.h> +#include <linux/mutex.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 oprofile_backtrace_depth; +static unsigned long is_setup; +static DEFINE_MUTEX(start_mutex); + +/* 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; + + mutex_lock(&start_mutex); + + 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 (oprofile_ops.sync_start) { + int sync_ret = oprofile_ops.sync_start(); + switch (sync_ret) { + case 0: + goto post_sync; + case 1: + goto do_generic; + case -1: + goto out3; + default: + goto out3; + } + } +do_generic: + if ((err = sync_start())) + goto out3; + +post_sync: + is_setup = 1; + mutex_unlock(&start_mutex); + return 0; + +out3: + if (oprofile_ops.shutdown) + oprofile_ops.shutdown(); +out2: + free_event_buffer(); +out1: + free_cpu_buffers(); +out: + mutex_unlock(&start_mutex); + return err; +} + +#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX + +static void switch_worker(struct work_struct *work); +static DECLARE_DELAYED_WORK(switch_work, switch_worker); + +static void start_switch_worker(void) +{ + if (oprofile_ops.switch_events) + schedule_delayed_work(&switch_work, oprofile_time_slice); +} + +static void stop_switch_worker(void) +{ + cancel_delayed_work_sync(&switch_work); +} + +static void switch_worker(struct work_struct *work) +{ + if (oprofile_ops.switch_events()) + return; + + atomic_inc(&oprofile_stats.multiplex_counter); + start_switch_worker(); +} + +/* User inputs in ms, converts to jiffies */ +int oprofile_set_timeout(unsigned long val_msec) +{ + int err = 0; + unsigned long time_slice; + + mutex_lock(&start_mutex); + + if (oprofile_started) { + err = -EBUSY; + goto out; + } + + if (!oprofile_ops.switch_events) { + err = -EINVAL; + goto out; + } + + time_slice = msecs_to_jiffies(val_msec); + if (time_slice == MAX_JIFFY_OFFSET) { + err = -EINVAL; + goto out; + } + + oprofile_time_slice = time_slice; + +out: + mutex_unlock(&start_mutex); + return err; + +} + +#else + +static inline void start_switch_worker(void) { } +static inline void stop_switch_worker(void) { } + +#endif + +/* Actually start profiling (echo 1>/dev/oprofile/enable) */ +int oprofile_start(void) +{ + int err = -EINVAL; + + mutex_lock(&start_mutex); + + if (!is_setup) + goto out; + + err = 0; + + if (oprofile_started) + goto out; + + oprofile_reset_stats(); + + if ((err = oprofile_ops.start())) + goto out; + + start_switch_worker(); + + oprofile_started = 1; +out: + mutex_unlock(&start_mutex); + return err; +} + + +/* echo 0>/dev/oprofile/enable */ +void oprofile_stop(void) +{ + mutex_lock(&start_mutex); + if (!oprofile_started) + goto out; + oprofile_ops.stop(); + oprofile_started = 0; + + stop_switch_worker(); + + /* wake up the daemon to read what remains */ + wake_up_buffer_waiter(); +out: + mutex_unlock(&start_mutex); +} + + +void oprofile_shutdown(void) +{ + mutex_lock(&start_mutex); + if (oprofile_ops.sync_stop) { + int sync_ret = oprofile_ops.sync_stop(); + switch (sync_ret) { + case 0: + goto post_sync; + case 1: + goto do_generic; + default: + goto post_sync; + } + } +do_generic: + sync_stop(); +post_sync: + if (oprofile_ops.shutdown) + oprofile_ops.shutdown(); + is_setup = 0; + free_event_buffer(); + free_cpu_buffers(); + mutex_unlock(&start_mutex); +} + +int oprofile_set_ulong(unsigned long *addr, unsigned long val) +{ + int err = -EBUSY; + + mutex_lock(&start_mutex); + if (!oprofile_started) { + *addr = val; + err = 0; + } + mutex_unlock(&start_mutex); + + return err; +} + +static int timer_mode; + +static int __init oprofile_init(void) +{ + int err; + + /* always init architecture to setup backtrace support */ + timer_mode = 0; + err = oprofile_arch_init(&oprofile_ops); + if (!err) { + if (!timer && !oprofilefs_register()) + return 0; + oprofile_arch_exit(); + } + + /* setup timer mode: */ + timer_mode = 1; + /* no nmi timer mode if oprofile.timer is set */ + if (timer || op_nmi_timer_init(&oprofile_ops)) { + err = oprofile_timer_init(&oprofile_ops); + if (err) + return err; + } + + return oprofilefs_register(); +} + + +static void __exit oprofile_exit(void) +{ + oprofilefs_unregister(); + if (!timer_mode) + 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"); |