134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/* CacheFiles statistics
|
|
*
|
|
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public Licence
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the Licence, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/seq_file.h>
|
|
#include "internal.h"
|
|
|
|
atomic_t cachefiles_lookup_histogram[HZ];
|
|
atomic_t cachefiles_mkdir_histogram[HZ];
|
|
atomic_t cachefiles_create_histogram[HZ];
|
|
|
|
/*
|
|
* display the latency histogram
|
|
*/
|
|
static int cachefiles_histogram_show(struct seq_file *m, void *v)
|
|
{
|
|
unsigned long index;
|
|
unsigned x, y, z, t;
|
|
|
|
switch ((unsigned long) v) {
|
|
case 1:
|
|
seq_puts(m, "JIFS SECS LOOKUPS MKDIRS CREATES\n");
|
|
return 0;
|
|
case 2:
|
|
seq_puts(m, "===== ===== ========= ========= =========\n");
|
|
return 0;
|
|
default:
|
|
index = (unsigned long) v - 3;
|
|
x = atomic_read(&cachefiles_lookup_histogram[index]);
|
|
y = atomic_read(&cachefiles_mkdir_histogram[index]);
|
|
z = atomic_read(&cachefiles_create_histogram[index]);
|
|
if (x == 0 && y == 0 && z == 0)
|
|
return 0;
|
|
|
|
t = (index * 1000) / HZ;
|
|
|
|
seq_printf(m, "%4lu 0.%03u %9u %9u %9u\n", index, t, x, y, z);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* set up the iterator to start reading from the first line
|
|
*/
|
|
static void *cachefiles_histogram_start(struct seq_file *m, loff_t *_pos)
|
|
{
|
|
if ((unsigned long long)*_pos >= HZ + 2)
|
|
return NULL;
|
|
if (*_pos == 0)
|
|
*_pos = 1;
|
|
return (void *)(unsigned long) *_pos;
|
|
}
|
|
|
|
/*
|
|
* move to the next line
|
|
*/
|
|
static void *cachefiles_histogram_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
return (unsigned long long)*pos > HZ + 2 ?
|
|
NULL : (void *)(unsigned long) *pos;
|
|
}
|
|
|
|
/*
|
|
* clean up after reading
|
|
*/
|
|
static void cachefiles_histogram_stop(struct seq_file *m, void *v)
|
|
{
|
|
}
|
|
|
|
static const struct seq_operations cachefiles_histogram_ops = {
|
|
.start = cachefiles_histogram_start,
|
|
.stop = cachefiles_histogram_stop,
|
|
.next = cachefiles_histogram_next,
|
|
.show = cachefiles_histogram_show,
|
|
};
|
|
|
|
/*
|
|
* open "/proc/fs/cachefiles/XXX" which provide statistics summaries
|
|
*/
|
|
static int cachefiles_histogram_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &cachefiles_histogram_ops);
|
|
}
|
|
|
|
static const struct file_operations cachefiles_histogram_fops = {
|
|
.open = cachefiles_histogram_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
/*
|
|
* initialise the /proc/fs/cachefiles/ directory
|
|
*/
|
|
int __init cachefiles_proc_init(void)
|
|
{
|
|
_enter("");
|
|
|
|
if (!proc_mkdir("fs/cachefiles", NULL))
|
|
goto error_dir;
|
|
|
|
if (!proc_create("fs/cachefiles/histogram", S_IFREG | 0444, NULL,
|
|
&cachefiles_histogram_fops))
|
|
goto error_histogram;
|
|
|
|
_leave(" = 0");
|
|
return 0;
|
|
|
|
error_histogram:
|
|
remove_proc_entry("fs/cachefiles", NULL);
|
|
error_dir:
|
|
_leave(" = -ENOMEM");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* clean up the /proc/fs/cachefiles/ directory
|
|
*/
|
|
void cachefiles_proc_cleanup(void)
|
|
{
|
|
remove_proc_entry("fs/cachefiles/histogram", NULL);
|
|
remove_proc_entry("fs/cachefiles", NULL);
|
|
}
|