Linux 5.19 Finally Removes Obsolete x86 a.out Support

[jabl]

That's it? Why even bother with this...

In the kernel there's two questions that are asked in situations like this:

1. Are there any users of this feature?
2. Is there anyone willing and able to maintain this feature?

If the answer to both of these questions is "No", then it can be ripped out.

[jabl]

(Some nitpicks...)

ext2 and ext3 are already handled by ext4 driver which was designed as backward compatible.

IIRC the ext3 driver was ripped out, as the ext4 is capable of working with ext3 filesystems. The ext2 driver is still there, as it's a very small and simple driver, and for some embedded device it might be the right choice to not pay for the code size overhead of the full ext4 driver. I think mainstream distros are built with the CONFIG_EXT4_USE_FOR_EXT2 option set, so the ext4 driver is used for ext2 filesystems and the ext2 driver isn't part of the kernel in that case.

AGP was also proposed for removal. For PCI and PCMCIA it's probably too early.

IIRC for AGP there was some plan to get rid of AGP GART support as that was buggy and x86-specific. I think even after that AGP would still be supported, but it would in practice be like just a somewhat faster PCI slot.

As for removing PCI, I think the vast majority of PCI and PCIe support code is shared so you can't really rip out one without the other.

As for architectures what about Power ISA?

AFAIU IBM is still maintaining POWER support, so I don't see that on the way out in the foreseeable future. If you want to rip out unused architectures, there's plenty of better options.

[microcode]

In the kernel there's two questions that are asked in situations like this:

1. Are there any users of this feature?
2. Is there anyone willing and able to maintain this feature?

If the answer to both of these questions is "No", then it can be ripped out.

It's like 300 lines... maintain what?

[Neraxa]

What else is probably going to get removed soon, and what do you wish would get removed?

I wish they would remove BIOS, ext2, ext3, ISA/PCI/AGP/PCMCIA and all architectures other than x86-64, ARM and RISC-V.

I strongly oppose removing BIOS because computers can last 15+ years, and even some computers from just a few years ago still had BIOS only. Linux should be able to tap into the market for reviving old systemms and not be an OS just for rich people who can afford $2000 gaming machines every 5 years. PCI is still used with many expansion cards. Old filesystems are often needed for reading old media and archives.

Removing a.out is meaningless from an architectural perspective. There may be old binaries only programs from the mid-90s someone may want to run. So, it would have not been my choice to remove it

[Neraxa]

(Some nitpicks...)



IIRC the ext3 driver was ripped out, as the ext4 is capable of working with ext3 filesystems. The ext2 driver is still there, as it's a very small and simple driver, and for some embedded device it might be the right choice to not pay for the code size overhead of the full ext4 driver. I think mainstream distros are built with the CONFIG_EXT4_USE_FOR_EXT2 option set, so the ext4 driver is used for ext2 filesystems and the ext2 driver isn't part of the kernel in that case.



IIRC for AGP there was some plan to get rid of AGP GART support as that was buggy and x86-specific. I think even after that AGP would still be supported, but it would in practice be like just a somewhat faster PCI slot.

As for removing PCI, I think the vast majority of PCI and PCIe support code is shared so you can't really rip out one without the other.



AFAIU IBM is still maintaining POWER support, so I don't see that on the way out in the foreseeable future. If you want to rip out unused architectures, there's plenty of better options.

Removing PCI and BIOS is nuts because there is hardware from not too long ago that is still working well. I have two BIOS computers. I can assure you its being used. So thats an insane idea