- * mlock: don't page populate if page has PROT_NONE permission.
- * munlock: the pages always do munlock althrough
- * its has PROT_NONE permission.
+ * mlock: don't page populate if vma has PROT_NONE permission.
+ * munlock: always do munlock although the vma has PROT_NONE
+ * permission, or SIGKILL is pending.