linux/fs/fscache/histogram.c
Thomas Gleixner b4d0d230cc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 114 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:27:11 +02:00

88 lines
2.2 KiB
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,
};