Re: Can Debian do multi-core "MY WAY"?

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From	<tomas@tuxteam.de>
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Subject	Re: Can Debian do multi-core "MY WAY"?
Date	Sat, 14 May 2016 23:00:02 +0200
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On Sat, May 14, 2016 at 12:31:28PM -0500, Richard Owlett wrote:
> I date from era when when "memory banks" were switched via contents
> of a I/O port ;/
> Anyone remember era when 8085 was "state of the art" ;/
> 
> I envision
>   core A using memory range X
>   core B using memory range Z

What you are describing is called "non uniform memory access" aka
NUMA [1] these days and yes, the Linux kernel takes into account
that different parts of memory have different "distances" to each
processor (e.g. by assigning process "affinities" to each CPU.

To a lesser extent, CPU caches do this too.

This is'nt surprising, since CPU bandwidth has outrun memory
bandwith significantly across the last 20-30 years. If a CPU
had to wait for every byte to arrive from main memory, they'd
be slower by a huge amount [2].

So in some way the answer is; yes, your PC and your OS is probably
doing it already :-)

regards

[1] https://en.wikipedia.org/wiki/Non-Uniform_Memory_Access
[2] http://gameprogrammingpatterns.com/data-locality.html

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Thread

Can Debian do multi-core "MY WAY"? Richard Owlett <rowlett@cloud85.net> - 2016-05-14 19:40 +0200
  Re: Can Debian do multi-core "MY WAY"? John Hasler <jhasler@newsguy.com> - 2016-05-14 19:50 +0200
    Re: Can Debian do multi-core "MY WAY"? Gene Heskett <gheskett@shentel.net> - 2016-05-14 20:50 +0200
  Re: Can Debian do multi-core "MY WAY"? Martin Read <zen75502@zen.co.uk> - 2016-05-14 20:20 +0200
  Re: Can Debian do multi-core "MY WAY"? Gene Heskett <gheskett@shentel.net> - 2016-05-14 20:30 +0200
    Re: Can Debian do multi-core "MY WAY"? John Hasler <jhasler@newsguy.com> - 2016-05-14 21:40 +0200
  Re: Can Debian do multi-core "MY WAY"? Joe <joe@jretrading.com> - 2016-05-14 20:30 +0200
  Re: Can Debian do multi-core "MY WAY"? <tomas@tuxteam.de> - 2016-05-14 23:00 +0200
    Re: Can Debian do multi-core "MY WAY"? Richard Owlett <rowlett@cloud85.net> - 2016-05-16 04:20 +0200
    Re: Can Debian do multi-core "MY WAY"? Richard Owlett <rowlett@cloud85.net> - 2016-05-16 04:20 +0200
      Re: Can Debian do multi-core "MY WAY"? Henrique de Moraes Holschuh <hmh@debian.org> - 2016-05-16 04:20 +0200

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