Little idea about 64 bit problem

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dizt3mp3r
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Re: Little idea about 64 bit problem

Post by dizt3mp3r »

And the other thing that the OP may not understand is: - ReactOS needs to copy 32bit Windows functionality and all the strange ways that it does what it does. We may not necessarily like all of how windows performs but if ReactOS diverges from Windows, ReactOS will not be Windows compatible in this possibly important respect.
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EmuandCo
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Re: Little idea about 64 bit problem

Post by EmuandCo »

The whole idea is far away from anything we try to accomplish. A WSL can only address the RAM the OS/Kernel can allocate to it, so the whole idea is not working at all. No 64 bit Kernel, no >4 GB RAM as PAE is no solution. There is no Wine or Linux in Windows, there is no RAMDisk in Windows. OK I could go on, but I think you got what I mean. We want it binary compatible and the way to get there has NO shortcuts. Do it right or don't do it at all. That's the reason why it takes a while to accomplish new big stuff in ROS, but there is no way to bypass that. If you want Linux, install Linux. If you want Windows, right now you HAVE TO use Windows. If you want us the be a alternative.... we accept patches. ^^

Btw, the whole idea is not needed anymore anyways: https://twitter.com/reactos/status/1404 ... 01796?s=20
This does mean ROS can use > 4GB RAM then, BUUUUUUT only 64 bit apps will run for now.
ReactOS is still in alpha stage, meaning it is not feature-complete and is recommended only for evaluation and testing purposes
PeterLinuxer
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Re: Little idea about 64 bit problem

Post by PeterLinuxer »

EmuandCo wrote: Wed Jun 16, 2021 1:39 pmBtw, the whole idea is not needed anymore anyways: https://twitter.com/reactos/status/1404 ... 01796?s=20
This does mean ROS can use > 4GB RAM then, BUUUUUUT only 64 bit apps will run for now.
There two question arise for me:
1. Have there ever been 32 bit programs that can access more than 4GB?
2. How is RAM usage >4GiB possible without PAE?

And then two comments from me:
1. Please don't call desktop applications apps. Apps are little phone proggies (who reenvent the wheels,) OK, I won't die if you continue to call them apps... ;)
2. As I am not on Twitter let me thank _here_ to the programmer who made the 8GiB RAM usage available, Timo Kreuzer. And of course thanks to all the other ROS devs, as an OS dev dilettant I'm aware that developing ReactOS is a _huge_ task!

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EmuandCo
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Re: Little idea about 64 bit problem

Post by EmuandCo »

1. No
2. It's impossible.

Apps ist short for Applications, so I will keep it that way ^^
ReactOS is still in alpha stage, meaning it is not feature-complete and is recommended only for evaluation and testing purposes
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dizt3mp3r
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Re: Little idea about 64 bit problem

Post by dizt3mp3r »

PeterLinuxer wrote: Wed Jun 16, 2021 5:49 pm
1. Please don't call desktop applications apps. Apps are little phone proggies (who reenvent the wheels,) OK, I won't die if you continue to call them apps... ;)
I've called applications - apps since they ran on Vax 11/750s back in the early 80s. The general public referred to them as programs and only those in the industry referred to computer applications, that applying to the use for that particular computer running x or y software (but normally only one piece of software at a time).

The term application became generally used or perhaps abused in the 90s and onward but program layers normally were referred to as applications or apps when you had a big computer controlling a factory and another doing the billing &c. When desktops powerful enough for general purpose use came along then most PC users still referred to 'programs' but I and many others were continuing to use the term 'app' as application seemed a bit pompous for a computer that ran lots and lots of programs.

Just because MS subverts the use of a name doesn't mean we can't still use it to mean what it originally meant, ie. a program that runs on the computer.
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PurpleGurl
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Re: Little idea about 64 bit problem

Post by PurpleGurl »

One thing neglected is that ROS is not Linux. It does not use all of Wine, just the parts that work in Windows. So there is nothing Linux underneath to latch onto to provide Long Mode support.
cb88
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Re: Little idea about 64 bit problem

Post by cb88 »

EmuandCo wrote: Wed Jun 16, 2021 6:13 pm 1. No
2. It's impossible.

Apps ist short for Applications, so I will keep it that way ^^
I'm not sure 1 is 100% true though it definitely is the rule... on a PAE enabled 32bit NT kernel while you cannot have a program that directly accesses greater than 4GB you can write a program that can utilize more than 4GB (just not all at once) and these are actually used by things like SQL and Exchange servers (AWE extensions), there is also shared memory which can allow fast access to out of process memory. This is mostly useful for large server type programs that need to have large chunks of data in memory but don't need to address them all at the same time they just need to there for quick acess (and this does cover a wide range of uses).

Basically it's down to semantics while neither method increases the process's address space beyond 4GB limits, it does allow the program to load much more than 4GB of data into memory... which it can then index/page into.

One thing to consider is that back in the day windows exchange servers could in fact use this in practice probably even on Windows Server 2003 Enterprise or Datacenter... which could do up to 64GB, granted such a machine would have been extremely expensive back then and only used by large companies, and even then they might have opted for alternatives.. that didn't require as much ram.

https://accu.org/journals/overload/21/113/oldwood_1875/
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