Questions tagged [multi-core]

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1answer
713 views

Feature of CPU needed to run Javascript fast

This is more of a Computer Engineering question, but what is the feature of a CPU to run Javascript fast? I use to access the internet with an AMD Phenom II with 6 cores and I could almost have as ...
61
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3answers
32k views

How does a single thread run on multiple cores?

I am trying to understand, at a high-level, how single threads run across multiple cores. Below is my best understanding. I do not believe it is correct though. Based on my reading of Hyper-threading,...
0
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1answer
131 views

Celluloid actors parallel work slow?

I'm new to actors and just playing around in ruby using Celluloid. I have this code below module Enumerable # Simple parallel map using Celluloid::Futures def pmap(&block) futures = map { ...
-6
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2answers
640 views

How does the web application support 150 max threads when the cpu only supports 2? [duplicate]

doing an lscpu cmd this is what i get $ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 2 On-line CPU(s) list: ...
6
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3answers
376 views

Why running threaded algorithms with exact number of cores the machine has, is faster than anything else?

I made some basic multi-threading tests here, and noticed that the speed increase when using the exact is bigger than I expected. I assumed that speed would increase linearly until I hit the limit of ...
1
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1answer
866 views

Multi-threading on a single core

Hypothetically, if you (I / someone) were to create a multi-threaded application, utilising the processing powers of multiple cores (for example, using TPL in C#). Would that program crash, if it were ...
-2
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2answers
225 views

Possible methods of accessing L1 cache and specifying threads/cores

A faster prime number generator with hyperthreading and L1 cache About five years ago I wrote a simple VB widget to generate the first one million prime numbers and then port them to into its single ...
-2
votes
3answers
439 views

Is it possible and faster to run an application on an unused CPU core?

Is it possible to move an application (or task) to another core to make it run faster and get all of that cores processing power? The way I understand it is that in an operating system applications ...
3
votes
1answer
538 views

Why does Node not support several event loops in one Process?

As the title says, why does Node not support several event loops in one Process? The idea, is that node spawns a user decided number of threads, which each have an event loop. When a new callback is ...
6
votes
1answer
917 views

How to write a doubly linked list for multi-core use without global lock?

I'm trying to write a cyclic doubly linked list where the nodes or even the link pointers are locked individualy. Or a lock-free or even wait-free (I think that's not possible) implementation. The ...
5
votes
3answers
3k views

How many threads should I use in my NIO server?

I've built a Java NIO TCP server, it currently uses four threads. One ServerRunnable thread that uses a selector and three worker threads. I've been looking around for some information about this, ...
55
votes
12answers
9k views

Why would a program require a specific minimum number of CPU cores?

Is it possible to write code (or complete software, rather than a piece of code) that won't work properly when run on a CPU that has less than N number of cores? Without checking it explicitly and ...
2
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0answers
162 views

Does OpenMp have support for Real Time Multiprocessor Computing?

I am working on a real time multiprocessor scheduling algorithm. I found very few results via google research related to it. A few simulators are available but are not robust enough. OpenMp is an ...
0
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0answers
69 views

Help in finding the total time taken by the entire production?

I have a line object and each line object has an array of tasks associated with it.Each task has a start time and an end time.Each task also has a list of tasks which are its predecessors. So if all ...
2
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1answer
1k views

Can we illustrate a CPU pipeline with a UML sequence diagram?

I study multicore pipelining and the diagrams are not UML sequence diagrams for instance Why not remake this diagram like an UML sequence diagram, would not that be more clear so that we can see ...
8
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2answers
3k views

Would Task-based programming in C++ require new language standard features?

So I saw this video on Youtube with all these C++ masters on GoingNative 2012 : Interactive panel where everybody could ask the questions. This is the video I was talking about: GoingNative 2012 - ...
13
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2answers
27k views

How to program thread allocation on multicore processors?

I would like to experiment with threads on a multi-core processor, e.g. to create a program that uses two different threads that are executed by two different processor cores. However, it is not ...
0
votes
1answer
285 views

MIPS has been used a multiprocessor architecture in the past. Is anyone using it in a multicore SoC? [closed]

I have been reading about the MIPS architecture and learned that it has been used a multiprocessor architecture in the past. Is anyone presently using it in a multicore SoC?
3
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3answers
2k views

What is a good way to learn about multicore programming at the kernel level in Linux? [closed]

I am interested in multicore programming at the kernel level. I expect this affects many areas and is probably different for each architecture. What are some must read sections of the kernel? If I ...
36
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7answers
4k views

Are there deprecated practices for multithread and multiprocessor programming that I should no longer use?

In the early days of FORTRAN and BASIC, essentially all programs were written with GOTO statements. The result was spaghetti code and the solution was structured programming. Similarly, pointers can ...
9
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2answers
21k views

How many make threads to use?

When I (re-)build large systems on a desktop/laptop computer, I tell make to use more than one thread to speed up the compilation speed, like this: $ make -j$[ $K * $C ] Where $C is supposed to ...
8
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4answers
5k views

Using Clojure instead of Python for scalability (multi-core) reasons, good idea? [closed]

After reading http://clojure.org/rationale and other performance comparisons between Clojure and many languages, I started to think that, apart from ease of use, I shouldn't be coding in Python ...
9
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6answers
711 views

Next in Concurrency

For past year I have been working a lot on concurrency in Java and have build and worked on many concurrent packages. So in terms of development in the concurrent world, I am quite confident. Further ...
2
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6answers
540 views

What threading pratice is good 90% of the time? [closed]

Since my SO thread was closed i guess i can ask it here. What practice or practices are good 90% of the time when working with threading with multiple cores? Personally all i have done was share ...
12
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8answers
821 views

How much effort should we spend to programming for multiple cores?

Processors are getting more and more cores these days, which leaves me wondering... Should we, programmers, adapt to this behaviour and spent more effort on programming for multiple cores? To what ...