1. IntroductionThere are two clocks of hardware clock and system clock in Linux. The hardware clock is the clock device on the motherboard, which is usually the clock that can be set on the BIOS screen. This time there is battery-powered maintenance on the motherboard, if the motherboard battery is exhausted, if the power outage, restore to the factory settings. The system clock refers to the clock in the k
Introduction: PAPI is a set of local interfaces for accessing the processor hardware performance counters, and using this interface to monitor the hardware execution characteristics of the Java program will help to discover the root cause of the program performance problem on the hardware layer of the computer system. This paper introduces the important concept o
In a computer, system resources include the interrupt request (IRQ) line, direct memory storage (DMA) channel, input/output (I/O) Port, and memory address. When the same system resources are allocated to two or more devices, a hardware conflict will occur and conflicting hardware devices will not work properly. The following methods can help you solve hardware co
If you develop a performance-intensive 3D game, you ' re always looking for ways to give users richer graphics, higher frame Rates, and better responsiveness. You also want to conserve the user's battery and keep the device from getting too warm during play. To the optimize of these areas, consider taking advantage of the hardware scaler that's available on almost AL L Android devices in the market today. How does it works and why do you should use i
In H.264 decoder, the implementation of cabac hardware accelerator H.264 has two kinds of entropy encoding solutions: one is context-based adaptive variable-length encoding developed from the variable-length encoding solution, and the other
One is context-based adaptive binary arithmetic code cabac developed from arithmetic coding. Compared with cavlc, cabac can save about 7% of the bitstream, but increase the computing speed by 10%.
. When decoding h
Hardware interruptions frequently consume CPU resources. If there is a way to allocate a large number of hardware interruptions to different CPUs (cores) under multi-core CPU conditions) processing clearly balances performance well. Currently, multiple CPUs, multiple NICs, and multiple hard disks are not supported on the server. If the NIC can be interrupted, one CPU (core) is exclusive) if the disk IO inte
Most software-only firewalls are based on the PC architecture and may adopt optimized OS as their operating platforms. The features are as follows: good scalability, adaptability, easy upgrade, and far lower cost than the hardware-based firewall. Most hardware-based firewalls use ASIC, and do not require OS support. They feature fast speed, good stability, and higher security factor than software firewalls,
On a computer, system resources include interrupt request (IRQ) lines, Direct memory storage (DMA) channels, input/output (I/O) ports, and memory addresses. A hardware conflict occurs when the same system resource is assigned to two or more devices, and the conflicting hardware devices will not function properly. The following methods can help you resolve hardware
minutes, 15 minutes in process queue flat Process quantity #如果每个cpu (can be calculated as CPU Core) The current number of active processes is not greater than 3, the system performance is good #如果每个cpu当前的活动进程书不大于4, indicating acceptable #如果每个cpu当前的活动进程书大于5, indicating a serious problemIf the CPU is dual-core, 0.00/2= is the average number of processes requested3, the level of the logEmerg emergency-System not availableAlert must take immediate actionCrit Fatal conditionError conditionWarn warni
, unsigned long N)Operating I/O memorySteps:1. Application2. Mapping3. Visit4. ReleaseRequest I/O memoryThe core functions are:Struct Resource *request_mem_region (unsigned long start, unsigned long len, char *name)This function applies a memory area that starts at start and is len bytes in length. If successful, returns non-null,Otherwise, NULL is returned, all existing in the I/O that are already in use/proc/iomem listed in theMapping I/O memoryBefore accessing IO memory, you must map the phys
above output as an example, the meaning of the expression is:The second hard drive interface (b), the second partition (2), the capacity is 75G, with 75G, usable is 0, so the utilization is 100%, is mounted to the root partition directory (/).The following is an explanation of the relevant commands:DF-HL Viewing disk space remainingDf-h viewing the partition size for each root pathDu-sh [directory Name] Returns the size of the directoryDU-SM [Folder] Returns the total number of M in this folder
; } cout"-----------------------------------------------"Endl; WSACleanup (); }voidGetsysinfo () {system_info sysInfo; //The structure contains information about the current computer: The architecture of the computer, the type of the central processing Unit, the number of central processors in the system, the size of the page, and other information. Osversioninfoex osvi; GetSystemInfo (sysInfo); Osvi.dwosversioninfosize=sizeof(OSVI); if(GetVersionEx (LPOSVERSIONINFOW) osvi)) {printf ("Operating
One: View CPUMore/proc/cpuinfo | grep "model name"grep "model name"/proc/cpuinfoIf you feel the need to see more comfortablegrep "model Name"/proc/cpuinfo | Cut-f2-d:Two: View memorygrep memtotal/proc/meminfogrep Memtotal/proc/meminfo | Cut-f2-d:Free-m |grep "Mem" | awk ' {print $} 'Three: Check whether the CPU is 32-bit or 64-bitGetconf Long_bitFour: Viewing the default languageEcho $LANG $LANGUAGEV: View kernel versionUname-rUname-aVI: View current timeDateSeven: View hard disks and partitions
1. View Kernel version#uname-ALinux mailserver2 2.6.32-279.el6.x86_64 #1 SMP Fri June 12:19:21 UTC + x86_64 x86_64 x86_64 gnu/linux#uname-R2.6.32-279.el6.x86_642. View Linux release software version#cat/etc/issueCentOS Release 6.3 (Final)Kernel \ r on an \m# Cat/etc/redhat-releaseCentOS Release 6.3 (Final)3. View partition information#fdisk-L4. View disk Information#df-HFile system capacity has been used with available percent mount points/DEV/MD122P3 20G 4.7G 14G 26%/Tmpfs 7.8G 272K 7.8G 1%/DEV
Restart Network ServiceXV: View the system hairstyle versionMethod 1For Linux systems, there are hundreds of distributions. For release version number View methodTake CentOS for example. Input lsb_release-a can beThis command applies to all Linux, including Redhat, SuSE, Debian, and other distributionsMethod 2If, for example, this command is notYou can view Cat/etc/xxx-release xx as the release name. such as centos-releaseMethod 3.You can also view the release version number by viewing the /etc
Device
The code of the device within Linux
IDE Hard Drive
/DEV/HD[A-D]
SCSI HDD
/DEV/SD[A-P]
U disk
/DEV/SD[A-P] (same as SCSI HDD)
CDROM
/dev/cdrom
Floppy disk Machine
/DEV/FD[0-1]
Printer
/DEV/LP[0-2]
Mouse
/dev/mouse
Tape drive
/dev/ht0 (IDE) or/dev/st0 (SCSI interface)
Card
/DEV/ETH[0-N]
Linux Miscellaneous (a
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