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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; |
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 | }; |