Messages in this thread | | | Date | Fri, 20 Jan 2006 15:42:12 +0100 (MET) | From | Jan Engelhardt <> | Subject | Re: [PATCH] leave APIC code inactive by default on i386 |
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>This patch is particularly useful for anybody booting a distro UP kernel >on a multi-chassis IBM x440/x445, because that system requires APIC >support to boot properly. If booting a UP kernel on a large SMP machine >seems silly, think of distro installer kernels. :) Joe Flakybox can run >his single-proc i386 box without APIC related breakage, and someone with >a x445 enable APICs in the UP kernel long enough to install a proper SMP >kernel. > >I know, it seems silly to be providing a patch that changes "enabled >unless explicitly disabled" to "disabled unless explicitly enabled", >especially since the APIC code can be forced off. However, I _am_ >curious to hear what people think about the other parts of the patch. >At the very least, I'm not quite convinced that noapic & nolapic are >doing their jobs, because it seems to me that get_smp_config pokes the >LAPIC and init_apic_mappings maps the IOAPICs into memory regardless of >whatever flags are passed. But, I'm not an APIC expert so I'll defer to >anybody who knows more than I. Most curiously, passing 'noapic nolapic' >still yields things like this in dmesg: > >Questions? Flames? The asbestos underpants have been strapped on. :)
Do you think that people can't properly configure their bootloader to include "noapic nolapic" in the options?
Jan Engelhardt -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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