linux-master/lib/find_bit_benchmark.c

14  * - randomly filled bitmap with approximately equal number of set and
16  * - sparse bitmap with few set bits at random positions.
29 static DECLARE_BITMAP(bitmap, BITMAP_LEN) __initdata;
34  * all other tests for the same bitmap because it sets all bits of bitmap to 1.
36 static int __init test_find_first_bit(void *bitmap, unsigned long len)
43 		i = find_first_bit(bitmap, len);
44 		__clear_bit(i, bitmap);
52 static int __init test_find_first_and_bit(void *bitmap, const void *bitmap2, unsigned long len)
58 	bitmap_copy(cp, bitmap, BITMAP_LEN);
71 static int __init test_find_next_bit(const void *bitmap, unsigned long len)
78 		i = find_next_bit(bitmap, BITMAP_LEN, i) + 1;
85 static int __init test_find_next_zero_bit(const void *bitmap, unsigned long len)
92 		i = find_next_zero_bit(bitmap, len, i) + 1;
99 static int __init test_find_last_bit(const void *bitmap, unsigned long len)
107 		l = find_last_bit(bitmap, len);
118 static int __init test_find_nth_bit(const unsigned long *bitmap, unsigned long len)
120 	unsigned long l, n, w = bitmap_weight(bitmap, len);
125 		l = find_nth_bit(bitmap, len, n);
134 static int __init test_find_next_and_bit(const void *bitmap,
142 		i = find_next_and_bit(bitmap, bitmap2, BITMAP_LEN, i + 1);
153 	pr_err("\nStart testing find_bit() with random-filled bitmap\n");
155 	get_random_bytes(bitmap, sizeof(bitmap));
158 	test_find_next_bit(bitmap, BITMAP_LEN);
159 	test_find_next_zero_bit(bitmap, BITMAP_LEN);
160 	test_find_last_bit(bitmap, BITMAP_LEN);
161 	test_find_nth_bit(bitmap, BITMAP_LEN / 10);
165 	 * traverse only part of bitmap to avoid soft lockup.
167 	test_find_first_bit(bitmap, BITMAP_LEN / 10);
168 	test_find_first_and_bit(bitmap, bitmap2, BITMAP_LEN / 2);
169 	test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
171 	pr_err("\nStart testing find_bit() with sparse bitmap\n");
173 	bitmap_zero(bitmap, BITMAP_LEN);
177 		__set_bit(get_random_u32_below(BITMAP_LEN), bitmap);
181 	test_find_next_bit(bitmap, BITMAP_LEN);
182 	test_find_next_zero_bit(bitmap, BITMAP_LEN);
183 	test_find_last_bit(bitmap, BITMAP_LEN);
184 	test_find_nth_bit(bitmap, BITMAP_LEN);
185 	test_find_first_bit(bitmap, BITMAP_LEN);
186 	test_find_first_and_bit(bitmap, bitmap2, BITMAP_LEN);
187 	test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);