Ingo Molnar wrote: > * Ray Lee <[EMAIL PROTECTED]> wrote: > >> Subject: [PATCH] x86_64: avoid sending LOCAL_TIMER_VECTOR IPI to >> itself >> >> Ray Lee reported, that on an UP kernel with "noapic" command line >> option set, the box locks hard during boot. > > i think this bug deserves a bit more attention, because similar problems > could be in other codepaths too. > > the problem here is that we tried to send an IPI to ourselves - which > confused Ray's system which has an IO-APIC, but where due to noapic we > keep the IO-APIC in its BIOS default. > > this isnt a new problem: the new time code just exposed it more > prominently that it was visible before. (the SMP kernel probably would > hang in a similar way on Ray's system)
Taking the hint, yes it does. (I'd never had a reason to test it before.) Booting an SMP kernel without NOAPIC works, with NOAPIC hangs fairly early on, implying a real fix to my problem belongs down at the arch level, I suppose. > i dont see any clear debugging in the IPI code that excludes self-IPIs. > I think the only valid way to do that is to use DEST_SELF. Andi? Ray - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
