diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-07 01:15:42 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-07 01:15:42 -0500 |
commit | a2e5790d841658485d642196dbb0927303d6c22f (patch) | |
tree | b3d28c9bcb7da6880806146fd22a88a7ee7f733e /lib/find_bit_benchmark.c | |
parent | ab2d92ad881da11331280aedf612d82e61cb6d41 (diff) | |
parent | 60c3e026d73ccabb075fb70ba02f8512ab40cf2c (diff) |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- kasan updates
- procfs
- lib/bitmap updates
- other lib/ updates
- checkpatch tweaks
- rapidio
- ubsan
- pipe fixes and cleanups
- lots of other misc bits
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
Documentation/sysctl/user.txt: fix typo
MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns
MAINTAINERS: update various PALM patterns
MAINTAINERS: update "ARM/OXNAS platform support" patterns
MAINTAINERS: update Cortina/Gemini patterns
MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern
MAINTAINERS: remove ANDROID ION pattern
mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors
mm: docs: fix parameter names mismatch
mm: docs: fixup punctuation
pipe: read buffer limits atomically
pipe: simplify round_pipe_size()
pipe: reject F_SETPIPE_SZ with size over UINT_MAX
pipe: fix off-by-one error when checking buffer limits
pipe: actually allow root to exceed the pipe buffer limits
pipe, sysctl: remove pipe_proc_fn()
pipe, sysctl: drop 'min' parameter from pipe-max-size converter
kasan: rework Kconfig settings
crash_dump: is_kdump_kernel can be boolean
kernel/mutex: mutex_is_locked can be boolean
...
Diffstat (limited to 'lib/find_bit_benchmark.c')
-rw-r--r-- | lib/find_bit_benchmark.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c new file mode 100644 index 000000000000..5985a25e6cbc --- /dev/null +++ b/lib/find_bit_benchmark.c | |||
@@ -0,0 +1,162 @@ | |||
1 | /* | ||
2 | * Test for find_*_bit functions. | ||
3 | * | ||
4 | * Copyright (c) 2017 Cavium. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of version 2 of the GNU General Public | ||
8 | * License as published by the Free Software Foundation. | ||
9 | * | ||
10 | * This program is distributed in the hope that it will be useful, but | ||
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
13 | * General Public License for more details. | ||
14 | */ | ||
15 | |||
16 | /* | ||
17 | * find_bit functions are widely used in kernel, so the successful boot | ||
18 | * is good enough test for correctness. | ||
19 | * | ||
20 | * This test is focused on performance of traversing bitmaps. Two typical | ||
21 | * scenarios are reproduced: | ||
22 | * - randomly filled bitmap with approximately equal number of set and | ||
23 | * cleared bits; | ||
24 | * - sparse bitmap with few set bits at random positions. | ||
25 | */ | ||
26 | |||
27 | #include <linux/bitops.h> | ||
28 | #include <linux/kernel.h> | ||
29 | #include <linux/list.h> | ||
30 | #include <linux/module.h> | ||
31 | #include <linux/printk.h> | ||
32 | #include <linux/random.h> | ||
33 | |||
34 | #define BITMAP_LEN (4096UL * 8 * 10) | ||
35 | #define SPARSE 500 | ||
36 | |||
37 | static DECLARE_BITMAP(bitmap, BITMAP_LEN) __initdata; | ||
38 | static DECLARE_BITMAP(bitmap2, BITMAP_LEN) __initdata; | ||
39 | |||
40 | /* | ||
41 | * This is Schlemiel the Painter's algorithm. It should be called after | ||
42 | * all other tests for the same bitmap because it sets all bits of bitmap to 1. | ||
43 | */ | ||
44 | static int __init test_find_first_bit(void *bitmap, unsigned long len) | ||
45 | { | ||
46 | unsigned long i, cnt; | ||
47 | ktime_t time; | ||
48 | |||
49 | time = ktime_get(); | ||
50 | for (cnt = i = 0; i < len; cnt++) { | ||
51 | i = find_first_bit(bitmap, len); | ||
52 | __clear_bit(i, bitmap); | ||
53 | } | ||
54 | time = ktime_get() - time; | ||
55 | pr_err("find_first_bit: %18llu ns, %6ld iterations\n", time, cnt); | ||
56 | |||
57 | return 0; | ||
58 | } | ||
59 | |||
60 | static int __init test_find_next_bit(const void *bitmap, unsigned long len) | ||
61 | { | ||
62 | unsigned long i, cnt; | ||
63 | ktime_t time; | ||
64 | |||
65 | time = ktime_get(); | ||
66 | for (cnt = i = 0; i < BITMAP_LEN; cnt++) | ||
67 | i = find_next_bit(bitmap, BITMAP_LEN, i) + 1; | ||
68 | time = ktime_get() - time; | ||
69 | pr_err("find_next_bit: %18llu ns, %6ld iterations\n", time, cnt); | ||
70 | |||
71 | return 0; | ||
72 | } | ||
73 | |||
74 | static int __init test_find_next_zero_bit(const void *bitmap, unsigned long len) | ||
75 | { | ||
76 | unsigned long i, cnt; | ||
77 | ktime_t time; | ||
78 | |||
79 | time = ktime_get(); | ||
80 | for (cnt = i = 0; i < BITMAP_LEN; cnt++) | ||
81 | i = find_next_zero_bit(bitmap, len, i) + 1; | ||
82 | time = ktime_get() - time; | ||
83 | pr_err("find_next_zero_bit: %18llu ns, %6ld iterations\n", time, cnt); | ||
84 | |||
85 | return 0; | ||
86 | } | ||
87 | |||
88 | static int __init test_find_last_bit(const void *bitmap, unsigned long len) | ||
89 | { | ||
90 | unsigned long l, cnt = 0; | ||
91 | ktime_t time; | ||
92 | |||
93 | time = ktime_get(); | ||
94 | do { | ||
95 | cnt++; | ||
96 | l = find_last_bit(bitmap, len); | ||
97 | if (l >= len) | ||
98 | break; | ||
99 | len = l; | ||
100 | } while (len); | ||
101 | time = ktime_get() - time; | ||
102 | pr_err("find_last_bit: %18llu ns, %6ld iterations\n", time, cnt); | ||
103 | |||
104 | return 0; | ||
105 | } | ||
106 | |||
107 | static int __init test_find_next_and_bit(const void *bitmap, | ||
108 | const void *bitmap2, unsigned long len) | ||
109 | { | ||
110 | unsigned long i, cnt; | ||
111 | cycles_t cycles; | ||
112 | |||
113 | cycles = get_cycles(); | ||
114 | for (cnt = i = 0; i < BITMAP_LEN; cnt++) | ||
115 | i = find_next_and_bit(bitmap, bitmap2, BITMAP_LEN, i+1); | ||
116 | cycles = get_cycles() - cycles; | ||
117 | pr_err("find_next_and_bit:\t\t%llu cycles, %ld iterations\n", | ||
118 | (u64)cycles, cnt); | ||
119 | |||
120 | return 0; | ||
121 | } | ||
122 | |||
123 | static int __init find_bit_test(void) | ||
124 | { | ||
125 | unsigned long nbits = BITMAP_LEN / SPARSE; | ||
126 | |||
127 | pr_err("\nStart testing find_bit() with random-filled bitmap\n"); | ||
128 | |||
129 | get_random_bytes(bitmap, sizeof(bitmap)); | ||
130 | get_random_bytes(bitmap2, sizeof(bitmap2)); | ||
131 | |||
132 | test_find_next_bit(bitmap, BITMAP_LEN); | ||
133 | test_find_next_zero_bit(bitmap, BITMAP_LEN); | ||
134 | test_find_last_bit(bitmap, BITMAP_LEN); | ||
135 | test_find_first_bit(bitmap, BITMAP_LEN); | ||
136 | test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN); | ||
137 | |||
138 | pr_err("\nStart testing find_bit() with sparse bitmap\n"); | ||
139 | |||
140 | bitmap_zero(bitmap, BITMAP_LEN); | ||
141 | bitmap_zero(bitmap2, BITMAP_LEN); | ||
142 | |||
143 | while (nbits--) { | ||
144 | __set_bit(prandom_u32() % BITMAP_LEN, bitmap); | ||
145 | __set_bit(prandom_u32() % BITMAP_LEN, bitmap2); | ||
146 | } | ||
147 | |||
148 | test_find_next_bit(bitmap, BITMAP_LEN); | ||
149 | test_find_next_zero_bit(bitmap, BITMAP_LEN); | ||
150 | test_find_last_bit(bitmap, BITMAP_LEN); | ||
151 | test_find_first_bit(bitmap, BITMAP_LEN); | ||
152 | test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN); | ||
153 | |||
154 | /* | ||
155 | * Everything is OK. Return error just to let user run benchmark | ||
156 | * again without annoying rmmod. | ||
157 | */ | ||
158 | return -EINVAL; | ||
159 | } | ||
160 | module_init(find_bit_test); | ||
161 | |||
162 | MODULE_LICENSE("GPL"); | ||