Operating system experiment 11: read / write the specified location information of the disk (just complete the reading)

Experiment 11: read / write the specified location information of the disk (just complete the reading) 1, Experimental purpose (1) Knowledge of Disk Physics. (2) Master the API for disk operation provided by Windows system. (3) Read / write the specified sector according to the entered sector number. 2, Experimental preparation knowledge: intro ...

Posted by floR on Wed, 25 May 2022 06:36:39 +0300

File related system calls in Linux Environment

System call: System calls are some functions provided by the operating system for programmers to call. These calls have been encapsulated in the form of C functions, but they are not part of standard C. General applications run in user mode (using 0 to 3G memory), and system calls work in kernel mode (using 3 to 4G memory). The commonly used ...

Posted by ghostdog74 on Sat, 14 May 2022 06:43:50 +0300

Linux kernel: file system and super block

catalogue Part I: file system module template 5 groups of system calls Hard coded SFS superblock and root inode Bare bone # SFS module is running Part II: file system on block device Real SFS on block device Part III: running file system In actual SFS operation Implementation behind running note   Part I: file system module templat ...

Posted by jackie11 on Fri, 13 May 2022 17:34:41 +0300

Linux - basic file system management disk partition

File system management Disk structure Logical structure of disk The size of each sector is fixed, 512Byte. A sector is also the smallest storage unit of a disk The size of the hard disk is the number of Heads used × Cylinders × sector number × The size of each sector is calculated according to the formula & ...

Posted by mdl on Wed, 11 May 2022 08:22:59 +0300

operating system in vernacular

Last time we talked about fork ing the process, copying most of the things, and then assigning values ​​to the personalized things. They point to different linear address spaces, but point to the same physical address space. copy-on-write The fork function only copies the page table, not the physical address space. In this way, if there is on ...

Posted by grim1208 on Thu, 28 Apr 2022 09:09:32 +0300

C language - process management

Basic concepts of process A process is an execution process of a program with certain functions about a data set. The Linux system supports multiple processes at the same time. A priority is set in the security information in each process attribute. The system determines the size of the time slice obtained by each process from the CPU acco ...

Posted by nevillejones on Tue, 26 Apr 2022 14:58:10 +0300

XV6 learning lab cow: copy on write fork

Code in github Come on. In general, if the COW mechanism is understood, the completion of this experiment is not very complicated. This experiment is to complete the COW (copy on write) fork. In the original XV6, the fork function was implemented by directly copying a complete copy of the address space of the process. However, copying the entir ...

Posted by voitek on Tue, 26 Apr 2022 13:53:35 +0300

XV6 learning (12) Lab lock: Parallelism/locking

Code in github upper This experiment is to optimize the lock inside XV6, reduce lock contention and improve the performance of the system. Memory allocator (moderate) The first experiment is to improve the memory page allocator of XV6 kernel, and the improved strategy is also discussed in the previous chapter. XV6 originally used a linked list ...

Posted by moon 111 on Mon, 25 Apr 2022 00:08:30 +0300

Familiar with Linux command, necessary for operation and maintenance engineer

Developers are exposed to Linux every day, especially after using Mac. They work in the command line environment with black background every day I don't have a good memory. I can't remember many useful linux commands very well. Now I'll summarize them gradually for later viewing. basic operation Linux shutdown, restart # Shut down shutdown ...

Posted by Muppet9010 on Sun, 24 Apr 2022 12:29:13 +0300

Five PV operations

1, Questions on the throne 1.1 production and consumer issues Note: don't set semaphores rigidly! Not necessarily empty, full, mutex. Analyze the relationship between processes. If P1 and P2 access a resource mutually exclusive, or if there is an i + + operation (need to be wrapped), there must be a mutually exclusive semaphore mutex; Because ...

Posted by ramesh_iridium on Sun, 17 Apr 2022 02:54:33 +0300