Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1#ifndef _LINUX_MMAN_H
2#define _LINUX_MMAN_H
3
4#include <asm/mman.h>
5
6#define MREMAP_MAYMOVE 1
7#define MREMAP_FIXED 2
8
9#define OVERCOMMIT_GUESS 0
10#define OVERCOMMIT_ALWAYS 1
11#define OVERCOMMIT_NEVER 2
12
13#ifdef __KERNEL__
14#include <linux/mm.h>
15
16#include <asm/atomic.h>
17
18extern int sysctl_overcommit_memory;
19extern int sysctl_overcommit_ratio;
20extern atomic_t vm_committed_space;
21
22#ifdef CONFIG_SMP
23extern void vm_acct_memory(long pages);
24#else
25static inline void vm_acct_memory(long pages)
26{
27 atomic_add(pages, &vm_committed_space);
28}
29#endif
30
31static inline void vm_unacct_memory(long pages)
32{
33 vm_acct_memory(-pages);
34}
35
36/*
37 * Optimisation macro. It is equivalent to:
38 * (x & bit1) ? bit2 : 0
39 * but this version is faster.
40 * ("bit1" and "bit2" must be single bits)
41 */
42#define _calc_vm_trans(x, bit1, bit2) \
43 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
44 : ((x) & (bit1)) / ((bit1) / (bit2)))
45
46/*
47 * Combine the mmap "prot" argument into "vm_flags" used internally.
48 */
49static inline unsigned long
50calc_vm_prot_bits(unsigned long prot)
51{
52 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
53 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
54 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC );
55}
56
57/*
58 * Combine the mmap "flags" argument into "vm_flags" used internally.
59 */
60static inline unsigned long
61calc_vm_flag_bits(unsigned long flags)
62{
63 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
64 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
65 _calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) |
66 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
67}
68#endif /* __KERNEL__ */
69#endif /* _LINUX_MMAN_H */