漫步量化

Overview理解access pointer vs. access memoryA slotted page has a fixed-size header that holds important information about the page and cells.[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-V2DpY0S7-1618197840390)(slotted%20page)]Slot in Computer Architectur..

OverheadOverhead is any combination of excess or indirect computation time, memory, bandwidth, or other resources that are required to perform a specific task.It is a special case of engineering overhead.Reclaim Wasted SpaceReclaim means retrieve o..

Overview访问指针和直接访问内存有何区别？C and C++ distinguish themselves from many other languages by permitting direct access to memory through the use of pointers.PointerPointer is an object in many programming languages that stores a memory address.Summaryp..

SectorThe smallest transfer unit of a spinning drive is a sector, so when some operation is performed, at least an entire sector can be read or written. Sector size typically range from 512 bytes to 4 Kb.FTLThe part of a flash memory controller resp..

Memory poolMemory pools (also called fixed-size blocks allocation) is the use of pools for memory management that allows dynamic memory allocation comparable to malloc or C++'s operator new.Many real-time operating systems use memory pools.PoolA po..

PageA page, memory page or virtual page is a fixed-length contigous block of virtual memory, described by a single entry in the page table.It is the smallest unit of data for memory mangement in a virtual memory OS.A page frame is the smallest fixed-l..

Dirve or diskFrom [2], the hard drive is where a computing device stores data for the long term.From techterms, a drive is a computer component used to store data. It may be a static device or may use removable media.Why are computer drives called “dr..

OverviewVectorized execution combines pipelining (avoidance of materialization of large intermediates) with the array-loops code patterns that make MonetDB fast.Vectorized primitives which typically perform a tight loop over arrays, are amenable to som..

cacheA CPU cache is a hardware used by the central processing unit (CPU) of a computer to reduce the average cost (time or energy) to access data from the main memory.Most CPUs have a hierarchy of multiple cache levels with separate instruction-specifi..

OverviewFrom ClickHouse, you can check if current CPU has support for SSE 4.2:$ grep -q sse4.2 /proc/cpuinfor && echo "SSE 4.2 supported" || echo "SSE 4.2 not supported"SSE4SSE4 (Streaming SIMD Extensions 4) is a SIMD CPU instruction set u..

OverviewFrom NumPy datetime64, there are many fundamental concepts.Datetimes are always stored based on POSIX time (though having a TAI mode which allows for accounting of leap-seconds is proposed), with an epoch of 1970-01-01T00:00:Z.ISO8601ISO ..

OverviewWSL docsThe Windows Subsytem for Linux lets developers run a GNU/Linux environment – including most command-line tools, utilities, and applications – directly on Windows, unmodified, without the overhead of a traditional virtual machine or du..

问题描述Window下使用VS Code,在terminal中select default shell ,选择WSL bash.此时,ternimal里是wsl,正常使用Linux命令,想要运行一个python文件有几种方案:ternimal里直接python file.py菜单栏-Terminal--Run Active File右键--Run Python File In Terminal(Ctrl+Shift+F10)1,2本质一样,可以正常运行.3此时调用的是Window路径,..

缘起《理解posixpath.py in Python》中提到，posixpath.py是针对POSIX系统的os.path源文件。From os.path, this is because different operating systems have different path name coventions.POSIX systemFrom wikipedia, POSIX(Portable Operating System Interface) is a family of st..

问题描述在Window启动terminal找不到WSL。出现：在配置文件列表中找不到你的默认配置文件-使用第一个配置文件。请进行检查以确保“defaultProfile"与你的某个配置文件的GUID相匹配。解决方案只找到refe1中提到了这个问题。注释掉source之后也不行，重启解决了。具体问题还没找到。ReferencesI cannot find the currect GUID in Windows Terminal for preview-4...

概念解析sambamount 命令 -t cifs -t drvfsSMBv3cifs-utilsmodprobe错误mount point does not exist.挂载之前，需要先建立挂载目录，即需要的 mkdir /mnt/xunknown filesystem type ‘cifs’.apt-get updateapt-get install cifs-utilsmount error: cifs filesystem not s..

问题在Windows上使用vscode debug 出现上述问题。本质是window cmd无法访问局域网内共享的文件夹。解决方案映射路径。计算机–右键—映射网络驱动器，将所需网络文件夹映射为本地磁盘。UNCUNC 路径不受支持。默认值设为 Windows 目录。将网络路径设置为vscode工作路径，会出现上述问题，需要解决unv路径支持问题。select default shell将cmd改为powershell，powershell支持跨平台操作。Refe..

Intel XeonIntel 至强系列处理器。Intel Xeon is a distinct product line from the similarly-named Intel Xeon Phi.From wikipedia, Xeon is a brand of x86 microprocessor designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server..