Messages in this thread | | | Subject | Re: [PATCH] Fix corruption of CONFIG_X86_32 in 'make oldconfig' | From | David Woodhouse <> | Date | Tue, 31 May 2011 12:43:29 +0100 |
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On Tue, 2011-05-31 at 12:41 +0200, Ingo Molnar wrote: > * David Woodhouse <dwmw2@infradead.org> wrote: > > > On Tue, 2011-05-31 at 09:53 +0200, Ingo Molnar wrote: > > > I'll always prefer typing: > > > make ARCH=x86_64 ... > > > To: > > > make ARCH=x86 CONFIG_64BIT=y ... > > > > Why else would you need to specify ARCH=x86 on the latter command line? > > Note that if we are consistent and implement the logical extension of > your CONFIG_64BIT 'fix' then we could pick up the target architecture > from the .config as well and not use the host architecture.
It would be interesting, perhaps, to make the architecture a config option. Distinctly non-trivial, though. I think it's been discussed before.
On the other hand, CONFIG_64BIT *is* a config option, and has been ever since we merged the 32-bit and 64-bit support into arch/x86.
> The very same arguments apply: the user provided an ARCH=arm .config, > why does 'make oldconfig' switch it to x86_64 automatically?
Yes, it's "automatic" because the architecture is *not* a config option. But yes, perhaps it would be nice if it *was*.
> Also, i prefer to type out the architecture due to: > | ...So if i get an ARM > | bugreport that gives me the appearance of a core kernel bug i will > | often start by converting that to an x86 .config via 'make > | ARCH=x86_64 oldconfig'. ]
So first you point out that it's automatic, and then you still specify it manually?
> But even if we leave out the 'ARCH=x86' portion, which ones are the > two shortest commands to type, in your opinion: > > make ARCH=i386 > make ARCH=x86_64 > make CONFIG_64BIT=y > > ? > > > You're not building on an x86 box? I always suspected you had some > > alien technology! Does it run Linux? > > Could you please stop with this borderline taunting tone? > > You've been wrong so many times in this thread that i think toning > down some of your shouting in favor of a bit more listening would be > well advised ...
No, Ingo. I haven't been wrong. I don't think either of us is *wrong*. Let's review a little...
- You like to use 'ARCH=i386' and 'ARCH=x86_64' as a convenient shortcut to override the CONFIG_64BIT option.
- I *don't* like it when the CONFIG_64BIT option is silently overridden according to the host architecture.
- I posted a patch making ARCH=x86 the default 'inferred' architecture, so that both of our desires are met.
- I was uncomfortable with keeping the legacy 'ARCH=i386' and 'ARCH=x86_64' settings around now that arch/i386 and arch/x86_64 are actually dead. I observed that while you have a valid need to set CONFIG_64BIT, that's a trick that actually works *only* on x86 because we haven't finished the merge and removed the dregs of the old architectures, and it works *only* for CONFIG_64BIT. It seems *unclean*. It doesn't work on anything *else* you might need to set to test 'core' functionality, such as CONFIG_SMP, and not on anything you might need to set to actually boot your kernel on a test box, such as CONFIG_SATA_MV, and not on anything else you might need to be compatible with the userspace on your test box, such as CONFIG_CGROUPS if you have a Fedora 15 userspace with systemd. And it doesn't *even* work for CONFIG_64BIT on any platforms other than x86, for example powerpc where the legacy ARCH=ppc and ARCH=ppc64 settings actually got removed when the merge was completed.
- I posted a patch which gives a more generic way to set config options from the make command line, which satisfies *all* the above requirements (except that it doesn't auto-enable dependencies, as observed). To me, it seems much cleaner and nicer. I observed that the legacy ARCH= trick *can* now be deprecated, but didn't actually post a patch which *does* deprecate or remove it.
- You objected, because you would have to type three more letters to enable CONFIG_64BIT, and a whole *five* more to disable it. Except you lied a bit in your message, adding a pointless 'ARCH=x86' to make it look like it was even *more* extra typing, and the world would actually end.
Did I miss something?
Aside from you adding 'ARCH=x86' to the example in your latest message to make it look like I'm going to contribute more to your RSI to I actually am, I don't think anyone was really *wrong*.
It's just a matter of opinion. I see this use of ARCH=i386 as a limited legacy hack, and implemented something which allows us to do that and much more in a *clean* and generic fashion. I happen to believe that even if it means we have to type a couple of extra characters when the command isn't in our command history already, it's worth it to have a clean generic interface instead of a legacy hack.
You, evidently, have a different opinion. That is your right. I think you're being *silly*, but I don't think you're *wrong*.
-- dwmw2
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