linux/drivers/oprofile/oprofile_files.c
Robert Richter 37ca5eb341 oprofile: set values to default when creating oprofilefs
This patch restores default values for:

/dev/oprofile/cpu_buffer_size
/dev/oprofile/buffer_watershed
/dev/oprofile/buffer_size

when creating the oprofilefs:

 # opcontrol --deinit
 # opcontrol --init
 # cat /dev/oprofile/cpu_buffer_size
 8192
 # echo 5123 > /dev/oprofile/cpu_buffer_size
 # cat /dev/oprofile/cpu_buffer_size
 5123
 # opcontrol --deinit
 # opcontrol --init
 # cat /dev/oprofile/cpu_buffer_size
 8192
 # opcontrol --deinit

This sets the values in a defined state. Before, there was no way to
restore the defaults without rebooting the system or reloading the
module.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:10 +01:00

145 lines
3.4 KiB
C

/**
* @file oprofile_files.c
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
*/
#include <linux/fs.h>
#include <linux/oprofile.h>
#include "event_buffer.h"
#include "oprofile_stats.h"
#include "oprof.h"
#define FS_BUFFER_SIZE_DEFAULT 131072
#define FS_CPU_BUFFER_SIZE_DEFAULT 8192
#define FS_BUFFER_WATERSHED_DEFAULT 32768 /* FIXME: tune */
unsigned long fs_buffer_size;
unsigned long fs_cpu_buffer_size;
unsigned long fs_buffer_watershed;
static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(backtrace_depth, buf, count, offset);
}
static ssize_t depth_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval)
return retval;
retval = oprofile_set_backtrace(val);
if (retval)
return retval;
return count;
}
static const struct file_operations depth_fops = {
.read = depth_read,
.write = depth_write
};
static ssize_t pointer_size_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
}
static const struct file_operations pointer_size_fops = {
.read = pointer_size_read,
};
static ssize_t cpu_type_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
return oprofilefs_str_to_user(oprofile_ops.cpu_type, buf, count, offset);
}
static const struct file_operations cpu_type_fops = {
.read = cpu_type_read,
};
static ssize_t enable_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
}
static ssize_t enable_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval)
return retval;
if (val)
retval = oprofile_start();
else
oprofile_stop();
if (retval)
return retval;
return count;
}
static const struct file_operations enable_fops = {
.read = enable_read,
.write = enable_write,
};
static ssize_t dump_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
{
wake_up_buffer_waiter();
return count;
}
static const struct file_operations dump_fops = {
.write = dump_write,
};
void oprofile_create_files(struct super_block *sb, struct dentry *root)
{
/* reinitialize default values */
fs_buffer_size = FS_BUFFER_SIZE_DEFAULT;
fs_cpu_buffer_size = FS_CPU_BUFFER_SIZE_DEFAULT;
fs_buffer_watershed = FS_BUFFER_WATERSHED_DEFAULT;
oprofilefs_create_file(sb, root, "enable", &enable_fops);
oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
oprofilefs_create_ulong(sb, root, "buffer_size", &fs_buffer_size);
oprofilefs_create_ulong(sb, root, "buffer_watershed", &fs_buffer_watershed);
oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &fs_cpu_buffer_size);
oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
oprofile_create_stats_files(sb, root);
if (oprofile_ops.create_files)
oprofile_ops.create_files(sb, root);
}