cpu | 易学教程

What are traps?

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问题 There are many different types of traps listed in processor datasheets, e.g. BusFault, MemManage Fault, Usage Fault and Address Error. What is their purpose? How can they be utilized in fault handling? 回答1: Traps are essentially subroutine calls that are forced by the processor when it detects something unusual in your stream of instructions. (Some processors make them into interrupts, but that's mostly just pushing more context onto the stack; this gets more interesting if the trap includes

How to catch the L3-cache hits and misses by perf tool in Linux

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问题 Is there any way to catch the L3-cache hits and misses by perf tool in Linux. According to the output of perf list cache , L1 and LLC cache are supported. According to the definition of perf_evsel__hw_cache array in perf's source code: const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX] [PERF_EVSEL__MAX_ALIASES] = { { "L1-dcache", "l1-d", "l1d", "L1-data", }, { "L1-icache", "l1-i", "l1i", "L1-instruction", }, { "LLC", "L2", }, { "dTLB", "d-tlb", "Data-TLB", }, { "iTLB", "i-tlb",

how to make Java use all CPU power on a machine?

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I sometimes write code in Java, and I noticed that sometimes it uses more than 100% CPU on a multicore machine. I am now running some code on a multicore machine that has 33 CPUs (Amazon's EC2), and I want to make my Java process use all CPUs available, so that it will have very high utilization of the machine. Is that possible, or is it left up to Java to decide when to use more than 100% CPU? I do not wish to change the code to use multithreading. Without using multiple threads or processes (or something other than the one process running), you won't be able to achieve n*100% usage on a n

I am trying to get an unique CPU ID

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I am using the code below to get a unique CPU ID, i found various samples on the web using this. However. By chance I happen to own 2 Asus Laptops. One is a quad core i5 the other an heavy duty i7 octocore both are 64 bit machines.. To my big surprise they both produce the same "unique" CPU ID ???. So this code isnt working for me, are there other methods to get unique CPU ids or do i do something wrong here. What I hope to get is a number that specific for each CPU that is made string cpuID = string.Empty; ManagementClass mc = new ManagementClass("win32_processor"); ManagementObjectCollection

Using Java to retrieve the CPU Usage for Window's Processes

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I am looking for a Java solution to finding the CPU usage for a running process in Windows. After looking around the web, there seems to be little information on a solution in Java. Keep in mind, I am not looking to find the CPU usage for the JVM, but any process running in Windows at the time. I am able to retrieve the memory usage in Java by using the exec("tasklist.exe ... ") to retrieve and parse process information. Although there is an aggregate CPU cycle timer for each process, I do not see a CPU usage column. Any help would be greatly appreciated. Also, if possible, I would like to

What is socket, core, threads, CPU? [closed]

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问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . I am currently volunteering to learn about linux servers and also I am interested in learning about cluster computing techniques. In this lab, they have a small cluster with one head node and two compute nodes. When I tried the lscpu command on head node, compute node1,node2. Click the link to view the details.

python process takes 100% CPU

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问题 I am trying to run python application and execute actions based on specified interval. Below code is consuming constantly 100% of CPU. def action_print(): print "hello there" interval = 5 next_run = 0 while True: while next_run > time.time(): pass next_run = time.time() + interval action_print() I would like to avoid putting process to sleep as there will be more actions to execute at various intervals. please advise 回答1: If you know when the next run will be, you can simply use time.sleep:

Get CPU temperature in python on windows

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Basically i want to read the cpu temperature in python. Please explain in layman's terms as i have never done this on windows before nor have i had to work with wmi. This is what I have at the moment: import wmi w = wmi.WMI(namespace="root\wmi") temperature_info = w.MSAcpi_ThermalZoneTemperature()[0] print temperature_info.CurrentTemperature (i got this code from this thread: Accessing CPU temperature in python ) however, on running the script, i get this error: Traceback (most recent call last): File "C:\Users\Ryan\Desktop\SerialSystemMonitor", line 4, in <module> temperature_info = w.MSAcpi

Node.js CPU load balancing

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问题 I created test with JMeter to test performance of Ghost blogging platform. Ghost written in Node.js and was installed in cloud server with 1Gb RAM, 1 CPU. I noticed after 400 concurrent users JMeter getting errors. Till 400 concurrent users load is normal. I decide increase CPU and added 1 CPU. But errors reproduced and added 2 CPUs, totally 4 CPUs. The problem is occuring after 400 concurrent users. I don't understand why 1 CPU can handle 400 users and the same results with 4 CPUs. During

To set the affinity of CPUs using C#

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问题 I have created a window application in C#.Now I want to set the CPU affinity for this application.I may have 2 processors,4 processors,8 processors or may be more than 8 processors. I want to set the cpu affinity using input from interface. How can i achieve this? How can it is possible to set the affinity using Environment.ProcessorCount? 回答1: Try this: Process.GetCurrentProcess().ProcessorAffinity = (System.IntPtr)2; Here's more about it. ProcessorAffinity represents each processor as a bit