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From: dieter <dieter@handshake.de>
Subject: Re: python and ARM memory types
Date: Mon, 05 Oct 2015 09:01:50 +0200
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Xref: csiph.com comp.lang.python:97399

voxner.dev@gmail.com writes:
> ...
> But how do I specify (streaming,write-combining,write-back) memory types in python ? Is there a library that I can use ? I am thinking of programming some fixed memory space (say 0x1000_000 - 0x2000_000) as "WC or WT or streaming" using the OS and then try to use the mmap facility in python. 

Python is quite a high level programming language - i.e. lots of things
are out of direct control of the programmer - among others memory management.

I suppose you will need an approach that gives you more control over
memory use - maybe, write your algorithms partially in the "C" programming
language.


You might find "cython" helpful to easily combine Python parts
and "C" parts.

"cython" is a compiler that compiles a source (which can use
a subset of Python and a subset of "C") into a "C" source file
which is then processed like a typical "C" source.

It takes care of a lot of the difficulties at the Python-C interface
and, thus, greatly facilitates combining Python and "C" parts.


> What set of libraries can I use ? Where should I start ? Fixed memories are discouraged so what kind of alternatives I can use ?

Note that modern operating systems virtualize memory. You will need a lot
of tricks to be able to use a specific range of physical memory in
"user level" processes -- but hopefully, you do not need to control
thing of the "physical memory level".