int mlockall (
int munlockall (void);
The mlockall function causes all of the pages mapped by the process's address space to be memory resident until unlocked by a call to the munlockall function, until the process exits, or until the process calls exec. MCL_CURRENT locks all of the pages currently mapped into the process's address space. MCL_FUTURE locks all of the pages that become mapped into the process's address space in the future, when those mappings are established. You can specify MCL_CURRENT and then subsequently specify MCL_FUTURE to lock both current and future address space.
The munlockall function unlocks all currently mapped pages of the process's address space. Any pages that become mapped into a process's address space after a call to munlockall are not locked unless otherwise specified by a subsequent call to mlockall. Pages locked or mapped into another process's address space are unaffected by this process's call to the munlockall function.
Locking the process's pages into memory also makes the process unswappable. When the pages are unlocked, the process is made swappable.
A lock is not inherited across a fork. All memory locks established on an address by this process are removed if an address range associated with the lock is unmapped with a call to the munmap function.
You must have superuser privileges to call the mlockall function.
On a successful call to the mlockall function, a value of 0 is returned and memory is locked. On an unsuccessful call, a value of -1 is returned, no memory is locked, and errno is set to indicate that an error occurred.
On a successful call to the munlockall function, a value of 0 is returned and memory is unlocked. On an unsuccessful call, a value of -1 is returned and errno is set to indicate that an error occurred.
The mlockall and munlockall functions fail under the following conditions:
If any of the following conditions occur, the mlockall function will fail:
Functions: exec(2), _exit(2), fork(2), munmap(2) delim off