108 lines
2.8 KiB
C
Executable File
108 lines
2.8 KiB
C
Executable File
/* FS-Cache latency histogram
|
|
*
|
|
* Copyright (C) 2008 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.
|
|
*/
|
|
|
|
#define FSCACHE_DEBUG_LEVEL THREAD
|
|
#include <linux/module.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/seq_file.h>
|
|
#include "internal.h"
|
|
|
|
atomic_t fscache_obj_instantiate_histogram[HZ];
|
|
atomic_t fscache_objs_histogram[HZ];
|
|
atomic_t fscache_ops_histogram[HZ];
|
|
atomic_t fscache_retrieval_delay_histogram[HZ];
|
|
atomic_t fscache_retrieval_histogram[HZ];
|
|
|
|
/*
|
|
* display the time-taken histogram
|
|
*/
|
|
static int fscache_histogram_show(struct seq_file *m, void *v)
|
|
{
|
|
unsigned long index;
|
|
unsigned n[5], t;
|
|
|
|
switch ((unsigned long) v) {
|
|
case 1:
|
|
seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS\n");
|
|
return 0;
|
|
case 2:
|
|
seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
|
|
return 0;
|
|
default:
|
|
index = (unsigned long) v - 3;
|
|
n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
|
|
n[1] = atomic_read(&fscache_ops_histogram[index]);
|
|
n[2] = atomic_read(&fscache_objs_histogram[index]);
|
|
n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
|
|
n[4] = atomic_read(&fscache_retrieval_histogram[index]);
|
|
if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
|
|
return 0;
|
|
|
|
t = (index * 1000) / HZ;
|
|
|
|
seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
|
|
index, t, n[0], n[1], n[2], n[3], n[4]);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* set up the iterator to start reading from the first line
|
|
*/
|
|
static void *fscache_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 *fscache_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 fscache_histogram_stop(struct seq_file *m, void *v)
|
|
{
|
|
}
|
|
|
|
static const struct seq_operations fscache_histogram_ops = {
|
|
.start = fscache_histogram_start,
|
|
.stop = fscache_histogram_stop,
|
|
.next = fscache_histogram_next,
|
|
.show = fscache_histogram_show,
|
|
};
|
|
|
|
/*
|
|
* open "/proc/fs/fscache/histogram" to provide latency data
|
|
*/
|
|
static int fscache_histogram_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &fscache_histogram_ops);
|
|
}
|
|
|
|
const struct file_operations fscache_histogram_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = fscache_histogram_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|