Memory management
Memory management is the act of managing computer memory. In its simpler forms, this involves providing ways to allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system.
Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the effectively available amount of RAM using disk swapping. The quality of the virtual memory manager can have a big impact on overall system performance.
Memory management systems on multi-tasking operating systems usually deal with the following issues.
ProtectionMain article: Memory protection
Processes should not be able to reference the memory for another process without permission. This is called memory protection, and prevents malicious or malfunctioning code in one program from interfering with the operation of other running programs.
SharingMain article: Shared memory
Even though the memory for different processes is normally protected from each other, different processes sometimes need to be able to share information and therefore access the same part of memory. Shared memory is one of the fastest techniques for Inter-process communication.
Logical organizationPrograms
are often organized in modules. Some of these modules could be shared between different programs, some are read only and some contain data that can be modified. The memory management is responsible for handling this logical organization that is different from the physical linear address space. One way to arrange this organization is segmentation.
Physical OrganizationMemory
is usually divided into fast primary storage and slow secondary storage. Memory management in the operating system handles moving information between these two levels of memory.
Memory management is the act of managing computer memory. In its simpler forms, this involves providing ways to allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system.
Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the effectively available amount of RAM using disk swapping. The quality of the virtual memory manager can have a big impact on overall system performance.
Memory management systems on multi-tasking operating systems usually deal with the following issues.
ProtectionMain article: Memory protection
Processes should not be able to reference the memory for another process without permission. This is called memory protection, and prevents malicious or malfunctioning code in one program from interfering with the operation of other running programs.
SharingMain article: Shared memory
Even though the memory for different processes is normally protected from each other, different processes sometimes need to be able to share information and therefore access the same part of memory. Shared memory is one of the fastest techniques for Inter-process communication.
Logical organizationPrograms
are often organized in modules. Some of these modules could be shared between different programs, some are read only and some contain data that can be modified. The memory management is responsible for handling this logical organization that is different from the physical linear address space. One way to arrange this organization is segmentation.
Physical OrganizationMemory
is usually divided into fast primary storage and slow secondary storage. Memory management in the operating system handles moving information between these two levels of memory.
No comments:
Post a Comment