From: Andi Kleen <a...@linux.intel.com> Subject: Re: [PATCH v2] perf/x86/intel: ignore CondChgd bit to avoid false NMI handling Date: Mon, 30 Jun 2014 15:22:24 -0700
>> >> I'm also interested in the behaviour of CondChgd bit on Ivy Bridge >> processors. > > The intended meaning of CondChgd is that a hardware debugger has taken over > the > PMU. It shouldn't really be set in other circumstances. > Thanks for your explanation. The hardware debugger you mean is a kind of ITP? > I think right now for perf it would be best to just ignore it. > > In theory could stop using the PMU, but if some BIOS set it it would > completely disable perf there. So better to just ignore it. > I'll reflect this information in the patch description. -- Thanks. HATAYAMA, Daisuke -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
