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Subject: Re: [PATCH 0/3] move __HAVE_ARCH_PTE_SPECIAL in Kconfig
To:     Vineet Gupta <Vineet.Gupta1@synopsys.com>,
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From:   Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date:   Mon, 9 Apr 2018 18:17:16 +0200
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On 09/04/2018 18:03, Vineet Gupta wrote:
> On 04/09/2018 06:57 AM, Laurent Dufour wrote:
>> The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
>> per architecture header files. This doesn't allow to make other
>> configuration dependent on it.
> 
> So I understand this series has more "readability" value and I'm fine with this
> change but I wonder if you really would want to make something depend on it or
> make this de-configurable. PTE special is really a fundamental construct - e.g.
> it is used for anon mapped pages where zero page has been wired up etc...

I don't want it to be de-configurable. This is almost like
ARCH_SUPPORTS_MEMORY_FAILURE, ARCH_USES_HIGH_VMA_FLAGS, ARCH_HAS_HMM...

These values are selected by per architecture Kconfig files and are not exposed
through the configuration menu.

Concerning making something depend on it, I will probably make
CONFIG_SPECULATIVE_PAGE_FAULT introduced by the SPF series dependent on it.
For details, please see https://lkml.org/lkml/2018/3/13/1143

Thanks,
Laurent.