Until the Linux kernel leverages instructions specific to Apple M1's extended ISA, this is a waste of time. The whole point of the M1 experience is that out of the box, it's fast, silent and runs for days. Yes, Linux will run, as it would run on any ARM processor, but it will be slow, hot and run the battery down in a couple of hours.
It will take years for the open-source community to reverse-engineer the ISA and write kernel code that optimally utilizes it. There's no shortcut here. Until then, it's not worth buying a Mac just to run Linux on it.
What instructions from an extended ISA are you referring to? The only ones I've seen written up have been:
1. Instructions to change the memory ordering mode, which allows Rosetta2 to skip some expensive memory fences when translating x86 binaries to ARM.
2. Some instructions for matrix math.
I wouldn't expect either of these to affect typical usage or battery life much, unless your workflow involves running things that do a ton of matrix math.
And the former isn't even an instruction, set a single bit in ACTLR_EL1 and off you go.
The second is an extension that talks to a coprocessor that's quite application specific. And that has an unstable ISA that changes every year. Probably not the biggest priority for anyone.
What specific instructions? I've been told by Apple fans on this site before release that Apple doesn't use non-standard instructions in their ISA and doesn't need special compiler treatment?
It will take years for the open-source community to reverse-engineer the ISA and write kernel code that optimally utilizes it. There's no shortcut here. Until then, it's not worth buying a Mac just to run Linux on it.