xref: /aosp_15_r20/external/ltp/testcases/kernel/controllers/memcg/memcontrol_common.h (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #ifndef MEMCONTROL_COMMON_H__
4 #define MEMCONTROL_COMMON_H__
5 
6 #include <stdlib.h>
7 #include <stdio.h>
8 
9 #include "tst_test.h"
10 
11 #define TMPDIR "mntdir"
12 #define MB(x) (x << 20)
13 
14 /*
15  * Checks if two given values differ by less than err% of their
16  * sum. An extra percent is added for every doubling of the page size
17  * to compensate for wastage in page sized allocations.
18  */
values_close(const ssize_t a,const ssize_t b,const ssize_t err)19 static inline int values_close(const ssize_t a,
20 			       const ssize_t b,
21 			       const ssize_t err)
22 {
23 	const size_t page_size = SAFE_SYSCONF(_SC_PAGESIZE);
24 	const ssize_t page_adjusted_err = ffs(page_size >> 13) + err;
25 
26 	return 100 * labs(a - b) <= (a + b) * page_adjusted_err;
27 }
28 
alloc_pagecache(const int fd,size_t size)29 static inline void alloc_pagecache(const int fd, size_t size)
30 {
31 	char buf[BUFSIZ];
32 	size_t i;
33 
34 	SAFE_LSEEK(fd, 0, SEEK_END);
35 
36 	for (i = 0; i < size; i += sizeof(buf))
37 		SAFE_WRITE(SAFE_WRITE_ALL, fd, buf, sizeof(buf));
38 }
39 
alloc_anon(const size_t size)40 static inline void alloc_anon(const size_t size)
41 {
42 	const size_t page_size = SAFE_SYSCONF(_SC_PAGESIZE);
43 	char *const buf = SAFE_MALLOC(size);
44 	size_t i;
45 
46 	for (i = 0; i < size; i += page_size)
47 		buf[i] = 0;
48 
49 	free(buf);
50 }
51 
52 #endif /* MEMCONTROL_COMMON_H__ */
53