The munlock() function shall unlock those whole pages containing any part of the address space of the process starting at address addr and continuing for len bytes, regardless of how many times mlock() has been called by the process for any of the pages in the specified range The implementation may require that addr be a multiple of {PAGESIZE} If any of the pages in the range specified to a call to munlock() are also mapped into the address spaces of other processes, any locks established on those pages by another process are unaffected by the call of this process to munlock() If any of the pages in the range specified by a call to munlock() are also mapped into other portions of the address space of the calling process outside the range specified, any locks established on those pages via the other mappings are also unaffected by this call Upon successful return from munlock(), pages in the specified range shall be unlocked with respect to the address space of the process Memory residency of unlocked pages is unspecified Upon successful completion, the munlock() function shall return a value of zero Upon unsuccessful completion, no change is made to any locks in the address space of the process Upon unsuccessful completion, the function shall return a value of -1 The munlock() function shall set errno = ENOMEM if some or all of the address range specified by the addr and len arguments does not correspond to valid mapped pages in the address space of the process The munlock() function may set errno = EINVAL if the addr argument is not a multiple of {PAGESIZE}