Hugepage/Superpage support for ARMv5 [closed] - linux-kernel

Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 years ago.
Improve this question
I was looking through some recent additions to the linux kernel which added code to support 1MB Pages for ARMv6 and ARMv7, Freebsd also has support built-in since 2013 but it is also limited to ARMv6 and ARMv7. Linux also supports the usage of huge-pages to map kernel-memory on ARMv5, but not for userspace.
As I'm thinking about adding support for userspace Hugepages on ARMv5 I would like to know if there are any architectural hurdles which make it impossible to implement.
Is there a reason hugepages are not supported for userspace applications on ARMv5? Or is it just a matter of "Somebody has to implement that"? On Linux i could see that they use the former access-permission/domain bits to save some extra information, AFAICT that would not be possible on ARMv5. But is that the only reason or is there something else I might have missed?

Related

Is it possible to high performance computing by Golang and CUDA? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 6 years ago.
Improve this question
I've googled for a while and the only useful infos are:
github.com/barnex/cuda5
mumax.github.io/
Unfortunately, the latest Arch Linux only provides CUDA 7.5 package, so the barnex's project may be not supported.
Arne Vansteenkiste recommends concurrency rather than pure Golang or Golang plus CUDA. What's more, there's someone says the same idea that "Wouldn't it be cool to start a goroutine on a GPU and communicate with it via channels?". I think both of these ideas are wonderful since I would like to change the existing code as little as possible instead of refactoring the whole program. Is the idea possible, or is there some documents introducing this topic in details?
Update
It seems that there's two bindings to HPC in Golang:
CUDA (< 6.0): github.com/barnex/cuda5
OpenCL: github.com/rainliu/gocl
Both of them are less documented, currently what I got is only Macro13's answer, very helpful, but it's more about java . So please help me some detailed materials in Golang. Thanks!

ARM Linux kernel development landscape [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 7 years ago.
Improve this question
I am in my learning the landscape of Linux kernel for ARM-based SoCs development.
This is the very early stage of learning and will surely take a long time as the matters seem to be comprehensive.
The goal is to have sufficient orientation in the eco-system so as soon as concrete issues in own project are to be solved one is able to route the search/investigation in the proper trails.
There is the Linus's tree, vanilla kernel. As for ARM platform there is also the ARM port tee/project/repository. If however to have a look at MAINTAINER file there are several maintainers/sub-systems of, apparently, ARM specific narrow-spectrum topics.
I wonder why all those narrow-spectrum topics do not deliver/contribute to the ARM port (http://www.arm.linux.org.uk/) repository instead of delivering directly to Torvalds tree?
There seems to exist also ARM SUB-ARCHITECTURES sub-system. Several those narrow-spectrum sub-systems/maintainers seem to be intended for porting to certain platform, conclusion based on naming the found sub-system/maintainer. Why are these centralized at / contribute to Linus tree directly instead of doing it to ARM SUB-ARCHITECTURES sub-system or as mentioned above?
The organization is somehow mysterious, in-transparent for a newbie.

Adapteva/ Parallela Chip [closed]

Closed. This question is off-topic. It is not currently accepting answers.
Want to improve this question? Update the question so it's on-topic for Stack Overflow.
Closed 10 years ago.
Improve this question
Does anyone know if this chip is 32-bit or 64-bit? I would like to know before I decide to purchase one of these boards for development.
According to the Microprocessor Report on Adapteva (PDF):
The design also eschews memory management of any kind, implementing a
flat 32-bit memory space without any protection
and also
The instruction set supports load and store double instructions that
access two consecutive 32-bit registers, taking advantage of the
64-bit path from the SRAM to the register file.
So it sounds like a 32-bit computer than can do some 64-bit operations.

What programming languages are normally compiled into non-machine specific code? [closed]

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 8 years ago.
Improve this question
Any specific reasons would be nice too.
As some people have pointed out; Java is translated into Bytecode, which runs in JVM. Are there any which don't depend on a virtual machine? Historical or contemporary, obsolete or not.
As already pointed out, portable ByteCode is platform independent,
you can find a List of ByteCode Languages on eg. wikipedia.
But they depend on an Interpreter or a Virtual Machine, ie. JVM.
And there is also LLVM, which provides a middle layer in an intermediate form (IF).

Compare OS X with Ubuntu [closed]

Closed. This question is off-topic. It is not currently accepting answers.
Want to improve this question? Update the question so it's on-topic for Stack Overflow.
Closed 11 years ago.
Improve this question
I should write a study, comparing two operating systems. My choice was OS X and Ubuntu, especially because the last Ubuntu, 11.11 (Oneiric Ocelot) seems to be as OS X Lion.
This two themes are too large - I would like to be more specific in my study - such as kernel or thread differences. Can you suggest me some ideas, which are large enough to write a study about them, but specifically good enough in the same time?
Thanks.
Some ideas to investigate:
license and freedom of software (and of user data).
the /proc filesystem
kernel limitations (number of threads, of processes, of inodes, max file sizes)
availability of cross platform framework libraries (like Qt)
hardware drivers & heterogeneity
thread implementations
dynamic libraries, plugins
graphical interfaces
availability of language implementations
etc etc

Resources