LInux 3.4 Kernel Has x32 ABI Support

[Nille]

I think most people could use a full x32 system because I don?t know of any app that requires more than 1 GB of RAM? No problem then.

I think no one will use x32 because which 32bit Apps we are using? Most commercial Programs and they are not x32. And please stop think that x64 is only more usable RAM.

[mrugiero]

I think no one will use x32 because which 32bit Apps we are using? Most commercial Programs and they are not x32. And please stop think that x64 is only more usable RAM.

Linux x32 is a new, native 32-bit ABI for x86_64 on Linux. Applications not needing 64-bit address space can now optionally target this 32-bit ABI to take advantage of the smaller 32-bit memory foot-print while still being able to take advantage of x86_64 CPU instructions and other functionality.

I think noone here thinks x86_64 is only about addressing more memory. It's just the only unused feature with this new architechture.

Also, not all of us use commercial programs. As I said, having the option is good. Defaulting it is probably a bad idea.
I don't use commercial programs on Linux. I don't need them. I mostly don't use them at all, aside from some games and WinRAR.

[Nille]

Is that limit only per application, or overall? Does x32 limit the total addressable memory to a (significantly) smaller value than x64?

You use an normal x64 Kernel and System. And Programs that can't compile to x64 can you now compile to x32 to benefits from the x64 architecture. So your System ca Address all your memory but each x32 program can only use 4GB.

[elanthis]

I think no one will use x32 because which 32bit Apps we are using? Most commercial Programs and they are not x32. And please stop think that x64 is only more usable RAM.

You're thinking like Linux is only applicable on the desktop.

That thinking is silly, because it's the least applicable place for Linux at all.

Large custom-built data centers -- like Google's -- have a LOT to gain by using x32, and very much planning on using it. For many workloads, the individual processes don't need a lot of virtual memory space, but can definitely use the 5-15% speedup over x86_64 (which in turn often has a huge speedup over IA32).

Chrome's NativeClient is another potential user.

Specialized mobile or embedded platforms running trimmed down AMD or Intel chips could easily use x32, since they don't even have close to 4GB of memory but can definitely use the extra speed/efficiency.

And frankly, I'd love this to take off on the desktop. I wish Microsoft supported something like it. Many applications (like games) rarely need more than 4GB of memory but could use the speed. Using IA32 means a crappier instruction set (no native 64-bit math, less register, no RIP, various other newer instructions are only available in long mode, etc.), and using x86_64 means paying the price for fatter pointers that may not be of any actual benefit to the application in question.

Is that limit only per application, or overall? Does x32 limit the total addressable memory to a (significantly) smaller value than x64?
I'm aware that IA32 architechture limits the addressable memory to 4GB and the memory per app to around 2GB (I don't fully recall the value), if I got the correct data.

It's per application. The kernel still runs in full x86_64 mode. x32 only affects the application/library stuff in usermode, and adds some alternate system calls to the kernel, whose only real purpose are to make sure the kernel isn't trying to hand off 64-bit pointers and such to the application.

[XorEaxEax]

Since you seem to understand the subject, I'll ask you.
Is that limit only per application, or overall? Does x32 limit the total addressable memory to a (significantly) smaller value than x64?
I'm aware that IA32 architechture limits the addressable memory to 4GB and the memory per app to around 2GB (I don't fully recall the value), if I got the correct data.

A little unsure here but I think it's per-app, but it's certainly 4gb and not 2gb, if you are running standard 32-bit programs under a 64-bit kernel they can also allocate 4gb, try compiling a program with -m32 and have it allocate 4gb, it will work.

edit: elanthis confirmed that it's per app. something insane is going on here, I just read a long post by elanthis and I agreed with everything he/she wrote... this can't be good

And please stop think that x64 is only more usable RAM.

True that x64 is more than only more addressable RAM, it has lots more registers aswell, BUT those registers are available for x32 aswell so the only difference between x32-x64 really is in the amount of addressable RAM and the downsized pointers in x32 which means smaller and sometimes faster code.

[AnonymousCoward]

I did my research, knew what I wanted and when I found it, I bought it... Having owned Android tablets for a couple of years was helpful, the stuff I learned in this forum was helpful, and taking my time was helpful.

Probably the biggest issue with the Android Tablets are companies that are out to make the quick buck, they have low prices on tablets that are not certified for the Android Marketplace, that's a killer.

If you do spend the money, from what I have seen, you get a good product.

[NomadDemon]

does it help to library hell for 32 bit app on 64 system?

[Nille]

does it help to library hell for 32 bit app on 64 system?

it make it more worse. because now you has tree different arch on your system. x86-64, x86 and x32. and each arch need his own libs etc. and the multiarch support is just beginning.

[NomadDemon]

so maybe x86 will be changed to x32 as default? it will clear x86 apps

[curaga]

There still exists plenty of hardware that cannot do 64-bit (x32 requires 64-bit capable hw).