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Date:   Thu, 6 Dec 2018 07:03:25 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     linux-kbuild@vger.kernel.org, Sam Ravnborg <sam@ravnborg.org>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jonathan Corbet <corbet@lwn.net>,
        Michal Marek <michal.lkml@markovi.net>
Subject: Re: [PATCH 2/3] kbuild: generate asm-generic wrappers if mandatory
 headers are missing
Message-ID: <20181206150325.GA2726@infradead.org>
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On Wed, Dec 05, 2018 at 08:28:05PM +0900, Masahiro Yamada wrote:
> Some time ago, Sam pointed out a certain degree of overwrap between
> generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121)
> 
> I a bit tweaked the meaning of mandatory-y; now it defines the minimum
> set of ASM headers that all architectures must have.
> 
> If arch does not have specific implementation of a mandatory header,
> Kbuild will let it fallback to the asm-generic one by automatically
> generating a wrapper. This will allow to drop lots of redundant
> generic-y defines.
> 
> Previously, "mandatory" was used in the context of UAPI, but I guess
> this can be extended to kernel space ASM headers.

How useful is it to keep the generic-y behavior around at all vs making
everything useful mandatory?