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Questions tagged [affinity]

Anything related to processor affinity, also known as CPU pinning. The processor affinity is a propriety of a process or a thread in an OS on multi-processor or multi-core systems that influences the OS' scheduling algorithm, binding the execution of that process (or thread) to a specific processor (or core). DO NOT use this tag as a synonym for [affinetransform] tag.

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how to set CPU affinity of a program?

I have a program written in C#, I am using VSTS 2008 + .Net 3.5 + Windows Vista Enterprise x86 to develop a Windows Forms application. My current computer is dual-core CPU, I want to set CPU affinity of my program to run on a specific CPU and free…
George2
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setting cpu affinity for linux kernel, not process

I am having a hard time finding information about how to set cpu affinity for linux kernel (with all of its loaded modules), NOT for a specific process. This is because I want the kernel to run on CPU 0 all the time to handle I/O stuff, and not do…
Nulik
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Why would one CPU core run slower than the others?

I was benchmarking a large scientific application, and found it would sometimes run 10% slower given the same inputs. After much searching, I found the the slowdown only occurred when it was running on core #2 of my quad core CPU (specifically, an…
Edi H
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How to set processor affinity from Batch File for Windows XP?

I've got a dual processor machine and I would like to launch an executable via a batch file on both processors. For example: (1) Launch Notepad.exe on Processor 1, and (2) Simultaneously, Notepad.exe on Processor 2 Currently, I'm using the…
JustADude
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What could cause my program to not use all cores after a while?

I have written a program that captures and displays video from three video cards. For every frame I spawn a thread that compresses the frame to Jpeg and then puts it in queue for writing to disk. I also have other threads that read from these files…
Nioreh
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How to start a thread on a specific core?

I have a quad core CPU, and lets say I always want to start a Thread on the second core. Is that possible in C#?
Rosmarine Popcorn
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Is sched_getcpu() reliable on Linux?

I'm trying to debug some performance issues with pthreads on Linux and I think sched_getcpu() may be lying to me. It reports a constant CPU for each thread, whereas profiling experiments seem to suggest the threads are actually migrating from one…
Paul R
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OpenMP: splitting loop based on NUMA

I am running the following loop using, say, 8 OpenMP threads: float* data; int n; #pragma omp parallel for schedule(dynamic, 1) default(none) shared(data, n) for ( int i = 0; i < n; ++i ) { DO SOMETHING WITH data[i] } Due to NUMA, I'd like to…
user2052436
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Obtaining thread Core affinity in C++ 11 through pthreads

I'm trying to set core affinity (Thread #1 goes on first core, Thread #2 goes on second core, ...) while using std::thread in C++ 11. I've already searched around various topics and on the internet and it seems C++ 11 API doesn't provide such low…
Cob013
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Pin processor CPU Isolation on Windows

In linux where I work mostly, we use a technique called CPU isolation, that effectively locks a process on to a processor and also prevents the processor from running anything else. Our kernel guys did some magic to handle the interrupts. In…
user805547
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Set processor affinity for MATLAB engine (Windows 7)

I'm developing an application in c++. One of the components of the application uses Matlab (via the Matlab engine) for data processing. At the same time, a data acquisition system is streaming data to disk. Occasionally, during periods of intensive…
tmpearce
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Using Pearson correlation in sklearn FeatureAgglomeration

I have a pandas dataframe with 100 rows and 10,000 features. I want to fit hierarchical clustering on my data by using pearson correlation as the affinity argument in sklearn.cluster.FeatureAgglomeration. I've tried two ways to make it work so…
Bruce Kent
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ixgbe: setting the number of RX/TX queues

I want to set the number of RX/TX queues used by an Intel 10G NIC. Let me explain why: I am using an Intel 10G NIC of type X520, on a Dell R720 system. I am using ixgbe version 3.6.7-k. The kernel in Ubuntu 3.2.0-59. I am running my network…
Ofir Hermesh
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Disable hyperthreading vs. changing ProcessorAffinity?

I have noticed that several of my multi-threaded calculations run faster if I disable hyper-threading in the BIOS. I have also learnt that I can programmatically disable the (logical) CPU:s by modifying the processor affinity for the current…
Anders Gustafsson
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How to prevent inheriting CPU affinity by child forked process?

I have a server process that forks many child processes. The server process has affinity to a CPU core, but I don't want that affinity to be inherited by child process (rather OS should handle where to run these processes). Is there a way to delink…
user424060
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