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Message-ID: <c54b4059-e3a7-40bd-84dc-013dc3b15c65@nvidia.com>
Date:   Fri, 8 Dec 2023 12:29:37 -0800
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 11/11] selftests: error out if kernel header files are
 not yet built
Content-Language: en-US
To:     David Hildenbrand <david@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Peter Xu <peterx@redhat.com>, Shuah Khan <shuah@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org
References: <20230606071637.267103-1-jhubbard@nvidia.com>
 <20230606071637.267103-12-jhubbard@nvidia.com>
 <20231103121652.GA6217@noisy.programming.kicks-ass.net>
 <a002f903-723f-40ae-8d7a-421ab2e082e2@redhat.com>
 <20231208151401.GG28727@noisy.programming.kicks-ass.net>
 <990feea2-c7a8-4cd9-8a6a-bc4bc1c2ffab@redhat.com>
From:   John Hubbard <jhubbard@nvidia.com>
In-Reply-To: <990feea2-c7a8-4cd9-8a6a-bc4bc1c2ffab@redhat.com>
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On 12/8/23 07:21, David Hildenbrand wrote:
> On 08.12.23 16:14, Peter Zijlstra wrote:
>> On Fri, Nov 03, 2023 at 01:22:54PM +0100, David Hildenbrand wrote:
>>> On 03.11.23 13:16, Peter Zijlstra wrote:
>>>> On Tue, Jun 06, 2023 at 12:16:37AM -0700, John Hubbard wrote:
>>>>> As per a discussion with Muhammad Usama Anjum [1], the following is 
>>>>> how
>>>>> one is supposed to build selftests:
>>>>>
>>>>>       make headers && make -C tools/testing/selftests/mm
>>>>>
>>>>> Change the selftest build system's lib.mk to fail out with a helpful
>>>>> message if that prerequisite "make headers" has not been done yet.
>>>>>
>>>>
>>>> NAK NAK NAK
>>>>
>>>> This now means I can no longer run selftests, I thank you very much! 
>>>> :-/
>>>>
>>>> root@spr:/usr/src/linux-2.6# make O=defconfig-build/ -j64
>>>> make[1]: Entering directory '/usr/src/linux-2.6/defconfig-build'
>>>> ***
>>>> *** The source tree is not clean, please run 'make mrproper'
>>>> *** in /usr/src/linux-2.6
>>>>
>>>>
>>>> I've always done:
>>>>
>>>>     cd tools/testing/selftests/x86; make
>>>>
>>>> and that has always worked
>>>>
>>>> Now I can't bloody well build *any* selftest or risk not being able to
>>>> do builds.
>>>
>>> This change landed in 6.5, no? And 6.6 was just released. Just 
>>> curious why
>>> you notice that now.
>>
>> And I hit it again (different box etc..)
>>
>> Can we please get this garbage fixed already?
> 
> I'd suggest to either revert or turn into a warning.

That would put us back into a half-broken sort of situation, though...
see below.

> 
> @John?
> 

I don't have a strong opinion about how this should be done, and in
fact I believed at the time that I was bringing the system into
compliance with what everyone wanted here. :)

There seem to be two conflicting visions:

a) The way it was (much) earlier: use ifdefs and defines to get by
without the latest kernel headers, or

b) Requiring recent kernel headers to build the various selftests.

Shuah, Peter, others: can we choose a direction please? Either
way will work, and I personally don't care which one we choose.


thanks,
-- 
John Hubbard
NVIDIA