Re: [PATCH V1] x86, espfix: postpone the initialization of espfix stack for AP

From	"H. Peter Anvin" <hpa@zytor.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH V1] x86, espfix: postpone the initialization of espfix stack for AP
Date	2015-06-17 23:20 +0200
Message-ID	<pCsUx-4PH-5@gated-at.bofh.it> (permalink)
References	(6 earlier) <pvgYa-4le-15@gated-at.bofh.it> <pwQZz-5G3-1@gated-at.bofh.it> <pxAg2-5Rt-29@gated-at.bofh.it> <pCfXk-2UO-3@gated-at.bofh.it> <pCsKR-4E6-1@gated-at.bofh.it>
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On 06/17/2015 02:04 PM, Borislav Petkov wrote:
>>
>> It isn't *at all* obvious to me at least that if the GFP_KERNEL
>> allocation fails we may not get rescheduled on another CPU and/or get stuck.
>>
>> I'm starting to think that the right thing to do is to allocate these on
>> the CPU that is bringing up the other CPU, at the same time we allocate
>> the percpu area.  This won't affect offline CPUs.
> 
> Btw, as part of experimenting for something else, I was able to trigger
> this even on a guest here. It is an insane guest though: 16 NUMA nodes,
> with 8 cores each:
> 

Is this reliable?

	-hpa

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Thread

Re: [PATCH V1] x86, espfix: postpone the initialization of espfix  stack for AP Borislav Petkov <bp@alien8.de> - 2015-06-17 23:10 +0200
  Re: [PATCH V1] x86, espfix: postpone the initialization of espfix  stack for AP "H. Peter Anvin" <hpa@zytor.com> - 2015-06-17 23:20 +0200
    Re: [PATCH V1] x86, espfix: postpone the initialization of espfix  stack for AP Borislav Petkov <bp@alien8.de> - 2015-06-18 00:00 +0200

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