[mirror_ubuntu-jammy-kernel.git] / fs / fscache / histogram.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache latency histogram
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#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)
{
}

const struct seq_operations fscache_histogram_ops = {
	.start		= fscache_histogram_start,
	.stop		= fscache_histogram_stop,
	.next		= fscache_histogram_next,
	.show		= fscache_histogram_show,
};
Commit	Line	Data
b4d0d230	1	// SPDX-License-Identifier: GPL-2.0-or-later
7394daa8 DH	2	/* FS-Cache latency histogram
	3	*
	4	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
7394daa8 DH	6	*/
	7
	8	#define FSCACHE_DEBUG_LEVEL THREAD
	9	#include <linux/module.h>
	10	#include <linux/proc_fs.h>
	11	#include <linux/seq_file.h>
	12	#include "internal.h"
	13
	14	atomic_t fscache_obj_instantiate_histogram[HZ];
	15	atomic_t fscache_objs_histogram[HZ];
	16	atomic_t fscache_ops_histogram[HZ];
	17	atomic_t fscache_retrieval_delay_histogram[HZ];
	18	atomic_t fscache_retrieval_histogram[HZ];
	19
	20	/*
	21	* display the time-taken histogram
	22	*/
	23	static int fscache_histogram_show(struct seq_file m, void v)
	24	{
	25	unsigned long index;
	26	unsigned n[5], t;
	27
	28	switch ((unsigned long) v) {
	29	case 1:
3185a88c	30	seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS\n");
7394daa8 DH	31	return 0;
7394daa8 DH	32	case 2:
3185a88c	33	seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
7394daa8 DH	34	return 0;
	35	default:
	36	index = (unsigned long) v - 3;
	37	n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
	38	n[1] = atomic_read(&fscache_ops_histogram[index]);
	39	n[2] = atomic_read(&fscache_objs_histogram[index]);
	40	n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
	41	n[4] = atomic_read(&fscache_retrieval_histogram[index]);
	42	if (!(n[0] \| n[1] \| n[2] \| n[3] \| n[4]))
	43	return 0;
	44
	45	t = (index * 1000) / HZ;
	46
	47	seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
	48	index, t, n[0], n[1], n[2], n[3], n[4]);
	49	return 0;
	50	}
	51	}
	52
	53	/*
	54	* set up the iterator to start reading from the first line
	55	*/
	56	static void fscache_histogram_start(struct seq_file m, loff_t *_pos)
	57	{
	58	if ((unsigned long long)*_pos >= HZ + 2)
	59	return NULL;
	60	if (*_pos == 0)
	61	*_pos = 1;
	62	return (void )(unsigned long) _pos;
	63	}
	64
	65	/*
	66	* move to the next line
	67	*/
	68	static void fscache_histogram_next(struct seq_file m, void v, loff_t pos)
	69	{
	70	(*pos)++;
	71	return (unsigned long long)*pos > HZ + 2 ?
	72	NULL : (void )(unsigned long) pos;
	73	}
	74
	75	/*
	76	* clean up after reading
	77	*/
	78	static void fscache_histogram_stop(struct seq_file m, void v)
	79	{
	80	}
	81
fddda2b7	82	const struct seq_operations fscache_histogram_ops = {
7394daa8 DH	83	.start = fscache_histogram_start,
	84	.stop = fscache_histogram_stop,
	85	.next = fscache_histogram_next,
	86	.show = fscache_histogram_show,
	87	};