Messages in this thread | | | Date | Wed, 30 Dec 1998 11:53:14 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: 2.2.0pre1 OOPS on boot. |
| |
On Wed, 30 Dec 1998, Alan Cox wrote: > > The Alpha has been through this pain to the point that people gave up on > the Linux instructions and installed NT simply because they couldn't work out > which kernel to install. We now have a generic kernel for the Alpha, thanks > to deep magic we have a generic kernel for the Sparc - which makes the intel > like look positively sane > > The x86 shouldnt make the same mistakes as the Alpha did.
Alan, calm down.
What Linux on alpha ended up doing was having a Generic kernel, and then the ability to compile for specific hardware.
And guess what? Linux/intel DOES THE SAME, and always has! There _is_ a generic kernel, and it's called CONFIG_M386.
When you ask the configuration process to optimize for certain CPU's, you lose the ability to run on some others. That has always been true: when you choose CONFIG_M486, you lose the ability to run on i386 machines, because then the kernel will take advantage of the fact that it _knows_ the memory management works properly.
I made a mistake in not documenting the fact that M586 means something else these days, but you, Alan, are just going ballistic for no good reason. Calm down, friend.
It probably _also_ makes sense to make the optimizations a bit more specific, so that we'd have:
- completely generic (rather than calling it "386" - just say that it is supposed to works on every ia32 machine) - 486-specific: the current i486, with the ridiculous alignments that that entails. Not recommended for _anything_ else than a i486. - i486+: the old "Pentium" - works on i486 machines, but without the stupid alignment, so it is smaller and faster on Pentium class machines too. Doesn't require a TSC, so it works on pseudo-pentiums too. This is apparently what you thought was "generic". - Pentium+: requires TSC - PentiumPro: requires TSC, conditional move instructions, and a fixed local APIC for SMP.
Would that kind of split work for you? We could also make it _really_ specific.
The above is essentially what we have now, but I added a "i486+" entry which is apparently what you were looking for. Ok?
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |