linux/drivers/oprofile/oprofile_files.c
Jason Yeh 1a960b402a Oprofile Multiplexing Patch
This patch introduces multiplexing support for the Oprofile kernel
module. It basically adds a new function pointer in oprofile_operator
allowing each architecture to supply its callback to switch between
different sets of event when the timer expires. Userspace tools can
modify the time slice through /dev/oprofile/time_slice.

It also modifies the number of counters exposed to the userspace through
/dev/oprofile. For example, the number of counters for AMD CPUs are
changed to 32 and multiplexed in the sets of 4.

Signed-off-by: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 11:48:16 +02:00

171 lines
3.9 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 <linux/jiffies.h>
#include "event_buffer.h"
#include "oprofile_stats.h"
#include "oprof.h"
unsigned long fs_buffer_size = 131072;
unsigned long fs_cpu_buffer_size = 8192;
unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
static ssize_t timeout_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(jiffies_to_msecs(timeout_jiffies),
buf, count, offset);
}
static ssize_t timeout_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_timeout(val);
if (retval)
return retval;
return count;
}
static const struct file_operations timeout_fops = {
.read = timeout_read,
.write = timeout_write,
};
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)
{
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);
oprofilefs_create_file(sb, root, "timeout_ms", &timeout_fops);
oprofile_create_stats_files(sb, root);
if (oprofile_ops.create_files)
oprofile_ops.create_files(sb, root);
}