On Thu, Mar 12, 2015 at 01:19:14AM +0000, Bryan O'Donoghue wrote: > On 11/03/15 23:10, Luis R. Rodriguez wrote: > > ACK the concept - the logic to compile up APIC support is circuitous > to say the least. It took me a while to grok this and indeed the goal was to make it much simpler to read, but at the same time to see if we can reach a compromise to simplify it for 32-bit. > Personally think we should just always compile up the APIC code if > the arch declares support and let the bootstrap code interrogate > CPUID. This would be the *next* level of compromise to make, I felt comfortable in raising the size compromise question for 32-bit but its not clear to me if this is a general question which we can address for all x86. There is indeed no performance pentalty for both so the question comes down to tex size increase, and its why I provided the numbers. My preference was to leave the optimization question for all x86 as a rather secondary question *iff* we can agree on something for 32-bit. > Who in 2015 is really running a system without an > APIC/IO-APIC and tip-of-tree Linux and does that one user care about > adding 12k to her kernel ? I suspect not and in any case can force > the APIC off with a command line argument I also figured this was the case, but figured it was safer to pose the question for 32-bit. If indeed folks who produce the hardware can conclude the size increase is reasonable for all platforms given no performance penalty then we can surely keep this even simpler -- I think its safer to ask this question for 32-bit and leave only the larger picture questoin as an evolutionairy question. > >@@ -899,6 +899,7 @@ config X86_UP_APIC > > bool "Local APIC support on uniprocessors" if !PCI_MSI > > Tried to apply this to torvalds-master to test :( Should it ? Which > branch are you on here ? > > Applying: x86: kconfig: remove X86_UP_IOAPIC > error: patch failed: arch/x86/Kconfig:899 > error: arch/x86/Kconfig: patch does not apply > Patch failed at 0001 x86: kconfig: remove X86_UP_IOAPIC linux-next tag next-20150311 Luis -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
