Ubuntu Plans For Linux x32 ABI Support

[Koorac]

2. Computers with (much) less than 4GB of RAM but with an x86_64 processor use x32 for the kernel and all the distro packages as much as possible. For third party apps you download from the web you would grab the x86 (32-bit) version and have an x86 compatibility environment installed, much in the tradition of x86_64. If an x32 web browser isn't compatible with an x86 plugin, you'd have to install an x86 browser. Sucks though because then you have x32 libs loaded for your desktop and x86 libs loaded for your browser, goodbye memory savings... hmm... will have to look into whether x86 Flash can work on an x32 browser without loading the entire x86 world into memory...

x32 for the kernel does not exist, this is just for userspace. You need a x86_64 kernel for it.
There will not be much need for x86_64 programs (except for e.g. big databases) since most applications are fine with < 4 GB RAM. It may be useful for mmap()ing large files though.

[allquixotic]

They should start working out the kinks with this arch ASAP so that they can provide it on x86_64 devices with 2 gigs of RAM and under ASAP. Don't want to know how many headers and non-portable codes assume that 32-bit pointers == x86 and 64-bit pointers == x86_64

Here's how I envision it working:

1. Computers with 4GB of RAM or more use native 64-bit arch because then you don't have to use PAE, which slows you down and defeats the purpose of using x32 (plus >= 4GB of RAM, the memory savings of x32 aren't going to be significant). These boxes will only have a native 64-bit and old x86 compatibility environment installed with no x32 support. Because if you try to support x86_64 AND x32 AND x86, you end up with so many different versions of libs loaded into memory that you defeat the purpose of trying to save memory by using x32.

2. Computers with (much) less than 4GB of RAM but with an x86_64 processor use x32 for the kernel and all the distro packages as much as possible. For third party apps you download from the web you would grab the x86 (32-bit) version and have an x86 compatibility environment installed, much in the tradition of x86_64. If an x32 web browser isn't compatible with an x86 plugin, you'd have to install an x86 browser. Sucks though because then you have x32 libs loaded for your desktop and x86 libs loaded for your browser, goodbye memory savings... hmm... will have to look into whether x86 Flash can work on an x32 browser without loading the entire x86 world into memory...

3. Computers that don't have an x86_64 capable processor would be stuck with the old x86 instruction set as before.

[phoronix]

Phoronix: Ubuntu Plans For Linux x32 ABI Support

With the x32 ABI for Linux finally coming together, Ubuntu developers are making plans to support this interesting ABI in the future...

http://www.phoronix.com/vr.php?view=MTEwMTk