📜  固定分区和可变分区的区别

📅  最后修改于: 2021-09-15 01:07:24             🧑  作者: Mango

1. 固定分区:
具有固定分区的多道编程是一种连续的内存管理技术,其中主内存被分成固定大小的分区,这些分区可以是相等或不等的。每当我们必须分配进程内存时,就会找到一个足够大以容纳进程的空闲分区。然后将内存分配给进程。如果没有可用空间,则进程在队列中等待分配内存。它是最古老的内存管理技术之一,易于实现。

2. 可变分区:
具有可变分区的多道程序是一种连续的内存管理技术,其中主内存不划分为多个分区,并且进程会被分配一块足够大的空闲内存以供其容纳。剩下的空间被认为是可以被其他进程进一步使用的空闲空间。它还提供了压缩的概念。在压缩中,空闲空间和未分配给进程的空间组合在一起,形成单个大内存空间。

固定分区和可变分区的区别:

S.NO. Fixed partitioning Variable partitioning
1. In multi-programming with fixed partitioning the main memory is divided into fixed sized partitions. In multi-programming with variable partitioning the main memory is not divided into fixed sized partitions.
2. Only one process can be placed in a partition. In variable partitioning, the process is allocated a chunk of free memory.
3. It does not utilize the main memory effectively. It utilizes the main memory effictively.
4. There is presence of internal fragmentation and external fragmentation. There is external fragmentation.
5. Degree of multi-programming is less. Degree of multi-programming is higher.
6. It is more easier to implement. It is less easier to implement.
7. There is limitation on size of process. There is no limitation on size of process.