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Date: Fri, 29 Oct 2010 00:26:55 -0700
From: Yinghai Lu <yinghai@kernel.org>
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To: Suresh Siddha <suresh.b.siddha@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
        Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>,
        Len Brown <lenb@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -v3] x86: Disable x2apic if nox2apic is specified
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On 10/28/2010 10:53 PM, Suresh Siddha wrote:
> On Tue, 2010-10-26 at 23:27 -0700, Yinghai Lu wrote:
>> For
>> 1. x2apic preenabled system
>> 2. first kernel have x2apic enabled, and try to kexec second kernel with "nox2apic"
>>
>> Will put back cpu with apic id < 255 into xapic mode, instead of panic.
>>
>> -v2: use x2apic_disabled instead of nox2apic, Suggested by Thomas
>>      update x2apic_supported with x2apic_disabled, Suggested by Thomas
>>
>> -v3: add checking for boot cpu apic id > 255. in that case will just panic
>>      --- pointed out by Suresh.
>>
> 
> Can we please hold off in merging this patch for a bit? There are some
> subtleties in going back to xapic when the platform/cpu's are in x2apic
> mode. I will check and get back to you on this after KS.

sure. take you time.

	Yinghai