Memory AllocationBefore implementing a memory allocator, let's define the memory regions to be managed by the allocator . = ALIGN(4); . += 128 * 1024; /* 128KB */ __stack_top = .; . = ALIGN(4096); __free_ram = .; . += 64 * 1024 * 1024; /* 64MB */ __free_ram_end = .;} This adds two new symbols,  __free_ram and __free_ram_end. This defines a memory area after the stack space. ..

3.7 Resource ServicesAll systems have limits imposed by their hardware architecture and configuration to ensure reasonable operation and to keep users from accidentally (or maliciously) creating resource shortages. (오오.. 모든 시스템은 한계를 가진다 by 안정성)At a minimum, the hardware limits must be imposed on processes that run on the system. It is usually desirable to limit processes further, below these har..

3.5 Memory-Management ServicesThe memory organization and layout associated with a FreeBSD process is shown in Figure 3.3. Each process begins execution with three memory segments: text, data, and stack. The data segment is divided into initialized data and uninitialized data (also known as bss). The text is read-only and is normally shared by all processes executing the file, whereas the data a..

2.6 Memory ManagementEach process has its own private address space. The address space is initially divided into three logical segments: text, data, and stack. The text segment is read-only and contains the machine instructions of a program. The data and stack segments are both readable and writable. The data segment contains the initialized and uninitialized data portions of a program, whereas ..

9. main memory - memory management 목표 – provide a convenient abstraction for programming (인터페이스) - Batch programming – program이 직접 physical address를 사용한다. - process 하나만 있던 시절에는 상관 없었음 -> multiple process – 메모리 관리의 필요성 발생 - 문제점 1) multiple process 2) 메인 메모리보다 큰 프로세스 (ex) 게임) -> Virtual memory 등장 : process 내부에서는 virtual, logical address 사용, 실제 RAM의 주소는 physical address - secondary storage, memory를..