Messages in this thread | | | Date | Sat, 30 Jun 2007 07:44:40 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH] - x86_64-add-ioapic-nmi-support-fix-3 |
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John Keller wrote: >> [adding Andi Kleen] >> >> John Keller wrote: >>> Place all the IOACPI NMI support code under CONFIG_ACPI >>> to clear up build errors with certain configs. >>> >>> Signed-off-by: John Keller <jpk@sgi.com> >>> --- >> Is there some architectural reason that IO APIC NMI support should >> require ACPI? > > OK, I guess standing alone this description was a bit misleading. > The code referred to here is the new code supporting the ACPI NMI SRC > structure that can be specified in the MADT. Without ACPI support this > code is not relevant. All the code touched by this patch was introduced > by eariler versions of this patchset. > > This patch makes no changes to the workings of nmi_watchdog.
OK, thanks for the clarification.
> John > > >> Is this a new requirement? It seems like a step backwards to me. >> >> >> Documentation/nmi_watchdog.txt doesn't say anything about ACPI being >> needed. It does say: >> >> "For x86-64, the needed APIC is always compiled in, and the NMI watchdog is >> always enabled with I/O-APIC mode (nmi_watchdog=1). Currently, local APIC >> mode (nmi_watchdog=2) does not work on x86-64. >> >> Using local APIC (nmi_watchdog=2) needs the first performance register, so >> you can't use it for other purposes (such as high precision performance >> profiling.) However, at least oprofile and the perfctr driver disable the >> local APIC NMI watchdog automatically."
-- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** - 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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