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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | /* 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 = {
.owner = THIS_MODULE,
.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);
}
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