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| author | Konstantin Khlebnikov <koct9i@gmail.com> | 2016-02-02 16:57:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-03 08:28:43 -0800 |
| commit | 30bdbb78009e67767983085e302bec6d97afc679 (patch) | |
| tree | 8d4084215738d98a6eed66cd7e971e9cca5f279a /mm | |
| parent | d977d56ce5b3e8842236f2f9e7483d4914c9592e (diff) | |
| download | op-kernel-dev-30bdbb78009e67767983085e302bec6d97afc679.zip op-kernel-dev-30bdbb78009e67767983085e302bec6d97afc679.tar.gz | |
mm: polish virtual memory accounting
* add VM_STACK as alias for VM_GROWSUP/DOWN depending on architecture
* always account VMAs with flag VM_STACK as stack (as it was before)
* cleanup classifying helpers
* update comments and documentation
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/internal.h | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/mm/internal.h b/mm/internal.h index 6e97630..a38a21e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -216,20 +216,35 @@ static inline bool is_cow_mapping(vm_flags_t flags) return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; } +/* + * These three helpers classifies VMAs for virtual memory accounting. + */ + +/* + * Executable code area - executable, not writable, not stack + */ static inline bool is_exec_mapping(vm_flags_t flags) { - return (flags & (VM_EXEC | VM_WRITE)) == VM_EXEC; + return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; } +/* + * Stack area - atomatically grows in one direction + * + * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: + * do_mmap() forbids all other combinations. + */ static inline bool is_stack_mapping(vm_flags_t flags) { - return (flags & (VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN))) != 0; + return (flags & VM_STACK) == VM_STACK; } +/* + * Data area - private, writable, not stack + */ static inline bool is_data_mapping(vm_flags_t flags) { - return (flags & ((VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN)) | - VM_WRITE | VM_SHARED)) == VM_WRITE; + return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; } /* mm/util.c */ |
