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Questions tagged [smp]

Symmetric multiprocessing (SMP)

Symmetric multiprocessing (SMP) involves a symmetric multiprocessor system hardware and software architecture where two or more identical processors connect to a single, shared main memory, have full access to all I/O devices, and are controlled by a single operating system instance that treats all processors equally, reserving none for special purposes. Most multiprocessor systems today use an SMP architecture. In the case of multi-core processors, the SMP architecture applies to the cores, treating them as separate processors.

wikipedia

38 questions
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4 answers

Execute curl requests in parallel in bash

What is the best way to execute 5 curl requests in parallel from a bash script? I can't run them in serial for performance reasons.
Justin
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5 answers

Why is CPU use so asymmetric on our 8-cpu SQL Server box?

I've noticed that the CPU usage on our 8-CPU database server, running SQL Server 2008, is not balanced at all. Here are the 1 day averages for a random day a while back, which is typical and consistently asymmetric: 9, 15, 10, 21, 18, 21, 14,…
Jeff Atwood
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2 answers

Multiple vCPUs or multiple identical VMs, which is better?

I am looking to upgrade one of our servers, an 8 core server running VMware Server 2. The VMs it runs are mostly web, file, and email servers; specifically, it runs three webservers, 2 email/file servers, and a few Jabber/XMPP Servers. When we…
Josh
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How can I tell if irqbalance is doing anything?

I've looked into linux server tuning docs that mention installing irqbalance (http://www.irqbalance.org/) on SMP systems. I'm looking at it now on a quad-core system, and while "ps axf" can tell me it is running, I don't see any stats or…
Stéphane
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2 answers

Enable SMP on Debian i386?

I've been running a couple old HP machines on Debian for a while, and only recently noticed that they were only 'recognizing' and using one processor. cat /proc/cpuinfo only shows output for processor #0, same with top, etc. And when I pulled the…
Libbux
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How can I override IRQ affinity for NVME devices

I am trying to move all interrupts over to cores 0-3 to keep the rest of my cores free for high speed, low latency virtualization. I wrote a quick script to set IRQ affinity to 0-3: #!/bin/bash while IFS= read -r LINE; do echo "0-3 ->…
Hubro
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Is it possible to tell which cpus are hyperthreads of the same core?

I have a server that is a quad-core i-7 with hyperthreading enabled. The kernel recognises this as 8 cpus, as it should. I want to create a couple virtual hosts running on this machine. virt-manager lets me select which cpus are used on which…
Exodist
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3 answers

Will multiple processors show in /proc/cpuinfo on a kernel that doesn't have SMP enabled?

I have recently migrated an application from one server to another and am having some issues I am wondering if they are associated to HyperThreading. In regards to my question, I currently don't have access to the old box. When I did, I know that…
ManiacZX
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3 answers

How to change SMP affinity of an IRQ on Ubuntu PV domU inside Xen XCP?

I'd like to change IRQ SMP affinity for reasons, outlined in this question: CPU0 is swamped with eth1 interrupts But I can't — I see Input/output error when I try to write to /proc/irq/*/smp_affinity. Please point me to the HOWTO on the matter. (A…
Alexander Gladysh
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1 answer

What will happen if a CPU burst up to 100% utilization in an SMP infrastructure?

I have a web server that has 4 CPUs, It has somehow encountered packet loss intermittently. Finally we moved allthe application and data to another system that has 8 CPUs. We did this because we found nothing was wrong except one phenomenon that the…
Jepsenwan
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Is a machine with a single NUMA node, actually a regular (non-NUMA) system?

First, let's check I got the fundamentals right: As I understand it, NUMA systems are a (asymmetric) network of NUMA nodes, where a NUMA node is usually (but not always) a physical CPU package. In a NUMA system, each node has its own local memory,…
Edd Barrett
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6 answers

24 Core Server Performance

I have a quad hexacore system based on the Opteron 8345 chips - that's 24 cores in all with 48GB of ram. This box was meant to replace the current six Intel core box which my current LAMP stack runs on. I am however getting even worse performance…
Khushil
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How can I emulate more virtual CPU than physically available?

In VMWare you can use multiple CPU, but only as much as present on the host. Is there a way to use more CPU than physically available ? It would be to : test software designed to run on an expensive 16-way box on commodity 2-way boxes. Use an…
Steve Schnepp
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5 answers

Reclaiming an old server

I got a server, four-2.6Ghz AMD opteron and 10Gigs RAM on TYAN Thunder board, for free. The thing is massive and loud, I'd like to reclaim the processors and RAM into two smaller computers each with two processors. Can someone suggest a motherboard…
nlucaroni
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Is one Xeon core enough to run a general website on my VPS?

I've purchased a VPS for dev work (at Linode) some time ago and am wishing to install NetBSD for the sake of experience, however its current support under the Xen hypervisor does not allow for SMP. I would assume this would mean I could only use one…
Ronald H.
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