Re: [next] [clang] x86_64-linux-gnu-ld: mm/mremap.o: in function `move_pgt_entry': mremap.c:(.text+0x763): undefined reference to `__compiletime_assert_342'

From: Steven Rostedt <rostedt@goodmis.org>
To: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Matthew Wilcox <willy@infradead.org>,
	Linux-Next Mailing List <linux-next@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
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	Nick Desaulniers <ndesaulniers@google.com>,
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	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [next] [clang] x86_64-linux-gnu-ld: mm/mremap.o: in function `move_pgt_entry': mremap.c:(.text+0x763): undefined reference to `__compiletime_assert_342'
Date: Thu, 17 Jun 2021 11:07:00 -0400	[thread overview]
Message-ID: <20210617110700.091efd15@gandalf.local.home> (raw)
In-Reply-To: <CA+G9fYukjZU9_88KuhW5FpG-Y6EOH4ehXgdKm9pGO0v4y4wsmA@mail.gmail.com>

On Thu, 17 Jun 2021 20:15:13 +0530
Naresh Kamboju <naresh.kamboju@linaro.org> wrote:

> > Your git bisect probably went astray.  There's no way that commit
> > caused that regression.  
> 
> Sorry for pointing to incorrect bad commits coming from git bisect.
> 
> Any best way to run git bisect on  linux next tree ?
> 
> Here is the git bisect log from gitlab pipeline,
> https://gitlab.com/Linaro/lkft/bisect/-/jobs/1354963448

Is it possible that it's not 100% reproducible?

Anyway, before posting the result of any commit as the buggy commit from a
git bisect, it is best to confirm it by:

 1) Checking out the tree at the bad commit.
 2) Verify that the tree at that point is bad
 3) Check out the parent of that commit (the commit before the bad commit
    was applied).
 4) Verify that the tree at that point is good

May need to repeat the above a couple of times, in case the issue is not
100% reproducible.

If the above is true, then post the patch as the bad commit. If it is not,
then something went wrong with the bisect.

-- Steve