close( fileDescriptor ); } return outError; } void ProcessFile(const char * inPathName) { size_t dataLength; void * dataPtr; char *appendStr = " append_key2"; int appendSize = (int)strlen(appendStr); if( MapFile
第二次机会法基于近似最佳置换算法(Approximate LRU Algorithm),它通过给每个页面分配一个位(也称为访问位或R位),用于标记页面是否被访问过。算法按顺序扫描页面,如果某个页面的位为0(即未被访问过),则将该页面置换出去;如果位为1(即已被访问过),则将位清零,并将页面移到链表的尾部,以给该页面一个新的机会...
Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2 --- Physical volumes --- PV Name /dev/mapper/mpatha PV UUID g60zN0-3sYn-qPbd-7y0M-dGfZ-hVs7-763Ywo PV Status allocatable Total PE / Free PE 74 / 74 PV Name /dev/mapper/mpathb PV UUID 5Uh...
4、虚拟文件系统VFS linux支持的所有文件系统称为逻辑文件系统,而linux在传统的逻辑文件系统的基础上增加料一个蓄念文件系统( Vitual File System ,VFS) 的接口层。 虚拟文件系统(VFS) 位于文件系统的最上层,管理各种逻辑文件系统,并可以屏蔽各种逻辑文件系统之间的差异,提供统一文件和设备的访问接口。 5、文件的逻辑...
This article provides guidance to troubleshoot Linux virtual machine (VM) boot issues caused by filesystem errors. Symptoms You can't connect to an Azure Linux virtual machine (VM) by using the Secure Shell Protocol (SSH), or the VM Agent status in theAzure portalisn'tReady. When...
blk_start_plug(&plug);while(nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || //active file也要被回收nr[LRU_INACTIVE_FILE]) { unsignedlongnr_anon, nr_file, percentage; unsignedlongnr_scanned; for_each_evictable_lru(lru) {if(nr[lru]) { ...
using a mechanism of array-based linked list to improve the searching and allocation algorithm in the memory pool, making the time complexity stable at O(1),and avoid the degradation of allocation and query performance when aquired memory mem number is too large in the traditional mem pool. ...
nullarbor:~ # echo 'file svcsock.c line 1603 +p' > 1. 在调试过程中,合理地在关键代码处插入 printk 输出调试信息是非常有效的方法。比如,在一个网络设备驱动程序中,当我们怀疑数据包的接收处理过程存在问题时,可以在接收函数的关键步骤处插入 printk 语句,输出数据包的相关信息,如数据包的长度、源地址、...
*/ do { tid = this_cpu_read(s->cpu_slab->tid); c = raw_cpu_ptr(s->cpu_slab); } while (IS_ENABLED(CONFIG_PREEMPT) && unlikely(tid != READ_ONCE(c->tid))); /* * Irqless object alloc/free algorithm used here depends on sequence * of fetching cpu_slab's data. tid should ...
The best approach to designing your own elevator algorithm, of course, is to sort by physical disk block. As discussed earlier, each file is broken up into logical blocks, which are the smallest allocation units of a filesystem. The size of a logical block is filesystem-dependent; each log...