| 摘要 |
PURPOSE:To clearly distinguish the run away of a program from the shortage of a main memory and to improve reliability by providing a means to judge whether a page fault address is the same as the value of a stack pointer or not. CONSTITUTION:When a fault address A is smaller than a stack extension boundary B, it is regarded as invalid address access caused by the run away of the program, and when the fault address A is larger than the stack extension boundary B, the fault address A is subtracted from a leading address C of a stack, and capacity to be extended is obtained. Next, the existence of the free area of physical space 2 for the obtained capacity is checked, and when the free area equivalent to the number of pages for an extension request exists, the free area is secured. When no free area exists, the fault address A is compared with the value of a stack pointer SP, and while the fault address A is judged as an invalid address at the time of noncoincidence, a waiting state is kept until the free area is given to the main memory at the time of coincidence. Thus, the run away of the program and the shortage of the main memory can be clearly distinguished, and the reliability of the processing can be widely improved. |
