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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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Setting CPU affinity using taskset

I am using the taskset tool to set CPU affinity for one of my programs. How do I set the affinity on a single CPU only - since I was not sure about this, so I was doing this: taskset -c 2-2 tests/prog 1 2 3 ...expecting, that I am scheduling the…
Sayan
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How to replace --cpus-per-proc with --map-by in OpenMPI

I need to update some old codes to work with the most recent version of OpenMPI, but I'm very confused by the new --map-by system. In particular, I'm not sure how to replace --cpus-per-proc N. Several websites have suggested using --map-by…
Kat S.
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Identify processor (core) is used by specific thread

I would like to know if it is possible to identify physical processor (core) used by thread with specific thread-id? For example, I have a multithreaded application that has two (2) threads (thread-id = 10 and thread-id = 20, for instance). I run…
DenisL
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Thread affinity with Windows, MSVC, and OpenMP

I want to bind the threads in my code to each physical core. With GCC I have successfully done this using sched_setaffinity so I no longer have to set export OMP_PROC_BIND=true. I want to do the same thing in Windows with MSVC. Windows and Linux…
Z boson
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assign two MPI processes per core

How do I assign 2 MPI processes per core? For example, if I do mpirun -np 4 ./application then it should use 2 physical cores to run 4 MPI processes (2 processes per core). I am using Open MPI 1.6. I did mpirun -np 4 -nc 2 ./application but wasn't…
codereviewanskquestions
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How to set the affinity of a process from a Linux kernel mode?

How can the CPU affinity of a process be set in kernel module? In user mode there is a syscall sched_setaffinity, but I am looking for the kernel mode equivalent. In the Linux kernel code, there is also a function called sched_setaffinity. It's…
Mike Mu
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Deployment affinity

I have k8s cluster with 3 nodes I would like that a sample deployment with 3 replicas as the follwing , so each pod got schduled in a different node ? apiVersion: apps/v1 kind: Deployment metadata: name: tomcat-deployment labels: app:…
Zamalkawy
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Is it possible to set pthread CPU affinity in OS X?

In Linux there is a sched_setaffinity() function defined in sched.h, but I can't seem to find anything like that in Mac OS X 10.6 pthreads implementation... If it is not possible to set affinity, what is the default policy in OS X?
Ryan
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Set affinity in std::thread before execution

I want to map certain threads to certain processors before the execution, in a way we do by passing pthread_attr_t in pthread_create, but with std::thread objects. I have tried the following: std::vector threads; for (int i = 0;…
k_kaz
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udp_recv cpu usage increase after setting CPU affinity

I wrote a simple udp_recv test demo, and I found one strange thing If I set the CPU affinity to cpu0, the cpu usage is 5%, but after setting affinity to other cpu, the cpu usage increased to 9%~12%,especially set to cpu20, the cpu usage is more than…
Patrick
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Unbound workqueue's kthreads CPU affinity

Is there a way to set CPU affinity for unbound workqueue's kthreads (those that named kthread/uXX:y)? Something like cpu mask for regular workqueues. Is it a good idea to set it for each kthread using taskset?
Filipp
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Pthread affinity before create threads

I need to set the affinity (thread to core, eg: 1st thread to 1st core) before creating a thread. Something like KMP_AFFINITY in OpenMP. Is it possible? edit: I try in this way, but dont' work :/ void* DoWork(void* args) { int nr = (int)args; …
JudgeDeath
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With MSI-X device can IRQ affinity be set (Linux)?

I've set IRQ affinity in the past on Linux by setting values to the proc files. [1] However, I noticed that when I do this on an system that uses MSI-X for the device (PCIe) that I want to set affinity for e.g. NIC, the /proc/interrupt counters…
jonschipp
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Compute affinity matrix from distance matrix

I used clustal omega to get a distance matrix of 500 protein sequences (they are homologous to each other). I want to use affinity propagation to cluster these sequences. Initially, because I observed by hand that the distance matrix only had values…
ericmjl
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To set the affinity of CPUs using C#

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…
Kandpal Lalit
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