diff options
Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r-- | drivers/oprofile/oprof.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c new file mode 100644 index 000000000000..b3f1cd6a24c1 --- /dev/null +++ b/drivers/oprofile/oprof.c @@ -0,0 +1,188 @@ +/** + * @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"); |