projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| b4d0d230 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 9ae326a6 DH |
2 | /* CacheFiles statistics |
| 3 | * | |
| 4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
| 5 | * Written by David Howells ([email protected]) | |
| 9ae326a6 DH |
6 | */ |
| 7 | ||
| 8 | #include <linux/module.h> | |
| 9 | #include <linux/proc_fs.h> | |
| 10 | #include <linux/seq_file.h> | |
| 11 | #include "internal.h" | |
| 12 | ||
| 13 | atomic_t cachefiles_lookup_histogram[HZ]; | |
| 14 | atomic_t cachefiles_mkdir_histogram[HZ]; | |
| 15 | atomic_t cachefiles_create_histogram[HZ]; | |
| 16 | ||
| 17 | /* | |
| 18 | * display the latency histogram | |
| 19 | */ | |
| 20 | static int cachefiles_histogram_show(struct seq_file *m, void *v) | |
| 21 | { | |
| 22 | unsigned long index; | |
| 23 | unsigned x, y, z, t; | |
| 24 | ||
| 25 | switch ((unsigned long) v) { | |
| 26 | case 1: | |
| 27 | seq_puts(m, "JIFS SECS LOOKUPS MKDIRS CREATES\n"); | |
| 28 | return 0; | |
| 29 | case 2: | |
| 30 | seq_puts(m, "===== ===== ========= ========= =========\n"); | |
| 31 | return 0; | |
| 32 | default: | |
| 33 | index = (unsigned long) v - 3; | |
| 34 | x = atomic_read(&cachefiles_lookup_histogram[index]); | |
| 35 | y = atomic_read(&cachefiles_mkdir_histogram[index]); | |
| 36 | z = atomic_read(&cachefiles_create_histogram[index]); | |
| 37 | if (x == 0 && y == 0 && z == 0) | |
| 38 | return 0; | |
| 39 | ||
| 40 | t = (index * 1000) / HZ; | |
| 41 | ||
| 42 | seq_printf(m, "%4lu 0.%03u %9u %9u %9u\n", index, t, x, y, z); | |
| 43 | return 0; | |
| 44 | } | |
| 45 | } | |
| 46 | ||
| 47 | /* | |
| 48 | * set up the iterator to start reading from the first line | |
| 49 | */ | |
| 50 | static void *cachefiles_histogram_start(struct seq_file *m, loff_t *_pos) | |
| 51 | { | |
| 52 | if ((unsigned long long)*_pos >= HZ + 2) | |
| 53 | return NULL; | |
| 54 | if (*_pos == 0) | |
| 55 | *_pos = 1; | |
| 56 | return (void *)(unsigned long) *_pos; | |
| 57 | } | |
| 58 | ||
| 59 | /* | |
| 60 | * move to the next line | |
| 61 | */ | |
| 62 | static void *cachefiles_histogram_next(struct seq_file *m, void *v, loff_t *pos) | |
| 63 | { | |
| 64 | (*pos)++; | |
| 65 | return (unsigned long long)*pos > HZ + 2 ? | |
| 66 | NULL : (void *)(unsigned long) *pos; | |
| 67 | } | |
| 68 | ||
| 69 | /* | |
| 70 | * clean up after reading | |
| 71 | */ | |
| 72 | static void cachefiles_histogram_stop(struct seq_file *m, void *v) | |
| 73 | { | |
| 74 | } | |
| 75 | ||
| 76 | static const struct seq_operations cachefiles_histogram_ops = { | |
| 77 | .start = cachefiles_histogram_start, | |
| 78 | .stop = cachefiles_histogram_stop, | |
| 79 | .next = cachefiles_histogram_next, | |
| 80 | .show = cachefiles_histogram_show, | |
| 81 | }; | |
| 82 | ||
| 9ae326a6 DH |
83 | /* |
| 84 | * initialise the /proc/fs/cachefiles/ directory | |
| 85 | */ | |
| 86 | int __init cachefiles_proc_init(void) | |
| 87 | { | |
| 88 | _enter(""); | |
| 89 | ||
| 90 | if (!proc_mkdir("fs/cachefiles", NULL)) | |
| 91 | goto error_dir; | |
| 92 | ||
| fddda2b7 CH |
93 | if (!proc_create_seq("fs/cachefiles/histogram", S_IFREG | 0444, NULL, |
| 94 | &cachefiles_histogram_ops)) | |
| 9ae326a6 DH |
95 | goto error_histogram; |
| 96 | ||
| 97 | _leave(" = 0"); | |
| 98 | return 0; | |
| 99 | ||
| 100 | error_histogram: | |
| 101 | remove_proc_entry("fs/cachefiles", NULL); | |
| 102 | error_dir: | |
| 103 | _leave(" = -ENOMEM"); | |
| 104 | return -ENOMEM; | |
| 105 | } | |
| 106 | ||
| 107 | /* | |
| 108 | * clean up the /proc/fs/cachefiles/ directory | |
| 109 | */ | |
| 110 | void cachefiles_proc_cleanup(void) | |
| 111 | { | |
| 112 | remove_proc_entry("fs/cachefiles/histogram", NULL); | |
| 113 | remove_proc_entry("fs/cachefiles", NULL); | |
| 114 | } |