[linux.git] / fs / fscache / histogram.c

/* FS-Cache latency histogram
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * 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 = {
	.open		= fscache_histogram_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
Commit	Line	Data
7394daa8 DH	1	/* FS-Cache latency histogram
	2	*
	3	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells ([email protected])
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#define FSCACHE_DEBUG_LEVEL THREAD
	13	#include <linux/module.h>
	14	#include <linux/proc_fs.h>
	15	#include <linux/seq_file.h>
	16	#include "internal.h"
	17
	18	atomic_t fscache_obj_instantiate_histogram[HZ];
	19	atomic_t fscache_objs_histogram[HZ];
	20	atomic_t fscache_ops_histogram[HZ];
	21	atomic_t fscache_retrieval_delay_histogram[HZ];
	22	atomic_t fscache_retrieval_histogram[HZ];
	23
	24	/*
	25	* display the time-taken histogram
	26	*/
	27	static int fscache_histogram_show(struct seq_file m, void v)
	28	{
	29	unsigned long index;
	30	unsigned n[5], t;
	31
	32	switch ((unsigned long) v) {
	33	case 1:
3185a88c	34	seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS\n");
7394daa8 DH	35	return 0;
7394daa8 DH	36	case 2:
3185a88c	37	seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
7394daa8 DH	38	return 0;
	39	default:
	40	index = (unsigned long) v - 3;
	41	n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
	42	n[1] = atomic_read(&fscache_ops_histogram[index]);
	43	n[2] = atomic_read(&fscache_objs_histogram[index]);
	44	n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
	45	n[4] = atomic_read(&fscache_retrieval_histogram[index]);
	46	if (!(n[0] \| n[1] \| n[2] \| n[3] \| n[4]))
	47	return 0;
	48
	49	t = (index * 1000) / HZ;
	50
	51	seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
	52	index, t, n[0], n[1], n[2], n[3], n[4]);
	53	return 0;
	54	}
	55	}
	56
	57	/*
	58	* set up the iterator to start reading from the first line
	59	*/
	60	static void fscache_histogram_start(struct seq_file m, loff_t *_pos)
	61	{
	62	if ((unsigned long long)*_pos >= HZ + 2)
	63	return NULL;
	64	if (*_pos == 0)
	65	*_pos = 1;
	66	return (void )(unsigned long) _pos;
	67	}
	68
	69	/*
	70	* move to the next line
	71	*/
	72	static void fscache_histogram_next(struct seq_file m, void v, loff_t pos)
	73	{
	74	(*pos)++;
	75	return (unsigned long long)*pos > HZ + 2 ?
	76	NULL : (void )(unsigned long) pos;
	77	}
	78
	79	/*
	80	* clean up after reading
	81	*/
	82	static void fscache_histogram_stop(struct seq_file m, void v)
	83	{
	84	}
	85
	86	static const struct seq_operations fscache_histogram_ops = {
	87	.start = fscache_histogram_start,
	88	.stop = fscache_histogram_stop,
	89	.next = fscache_histogram_next,
	90	.show = fscache_histogram_show,
	91	};
	92
	93	/*
	94	* open "/proc/fs/fscache/histogram" to provide latency data
	95	*/
	96	static int fscache_histogram_open(struct inode inode, struct file file)
	97	{
	98	return seq_open(file, &fscache_histogram_ops);
	99	}
	100
	101	const struct file_operations fscache_histogram_fops = {
7394daa8 DH	102	.open = fscache_histogram_open,
	103	.read = seq_read,
	104	.llseek = seq_lseek,
	105	.release = seq_release,
	106	};