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Message-ID: <783a4178-1dec-4e30-989a-5174b8176b09@redhat.com>
Date:   Wed, 13 Dec 2023 10:59:01 +0100
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Subject: Re: [PATCH v6 5/5] selftests/mm: add UFFDIO_MOVE ioctl test
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To:     John Hubbard <jhubbard@nvidia.com>,
        Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Mark Brown <broonie@kernel.org>
Cc:     Suren Baghdasaryan <surenb@google.com>, akpm@linux-foundation.org,
        viro@zeniv.linux.org.uk, brauner@kernel.org, shuah@kernel.org,
        aarcange@redhat.com, lokeshgidra@google.com, peterx@redhat.com,
        ryan.roberts@arm.com, hughd@google.com, mhocko@suse.com,
        axelrasmussen@google.com, rppt@kernel.org, willy@infradead.org,
        Liam.Howlett@oracle.com, jannh@google.com, zhangpeng362@huawei.com,
        bgeffon@google.com, kaleshsingh@google.com, ngeoffray@google.com,
        jdduke@google.com, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, kernel-team@android.com,
        Peter Zijlstra <peterz@infradead.org>
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From:   David Hildenbrand <david@redhat.com>
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On 13.12.23 06:55, John Hubbard wrote:
> On 12/12/23 21:52, John Hubbard wrote:
>> On 12/12/23 19:58, Muhammad Usama Anjum wrote:
>>>> ...
>>>> Oh, this sounds like it would work nicely. No more "make headers"
>>>> required (hooray!). Instead, the new approach would be "selftests are
>>>> allowed to include from tools/include", and then we can just start
>>>> copying the files that we need to that location, and gradually fix up
>>>> all the selftests.
>>> No, this wouldn't work.
>>> * The selftests are applications which include default header files. The
>>> application don't care from where the header files are picked up at
>>> compile
>>> time. We should be able to build the application on normal system with
>>> latest headers installed without any changes.
>>> * The header files cannot be included directly as they need to be
>>> processed
>>> first which is done by `make headers`. Here is a diff between kernel fs.h
>>> and processed header file to be used by applications:
>>
>> Well, that's not the proposal. The idea is to snapshot various uapi/
>> headers
>> into tools/include, just like what is already being done:
>>
>> $ diff ./include/uapi/linux/fs.h ./tools/include/uapi/linux/fs.h
>> $
> 
> Oh sorry, that's exactly what you were saying you don't want. ahem. :)
> 
> Another variation though, would be to run "make headers", and snapshot
> some of those files into tools/include.

^ this is what I had in mind

If you're writing a test that needs some new fancy thing, update the 
relevant header.

-- 
Cheers,

David / dhildenb