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Date:   Tue, 30 May 2023 15:19:21 -0700
From:   Dan Williams <dan.j.williams@intel.com>
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        Dan Williams <dan.j.williams@intel.com>
CC:     Sedat Dilek <sedat.dilek@gmail.com>,
        Johan Hovold <johan@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
        <mcgrof@kernel.org>
Subject: Re: Revert "module: error out early on concurrent load of the same
 module file"
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Linus Torvalds wrote:
> On Tue, May 30, 2023 at 5:43 PM Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > [ add linux-cxl ]
> >
> > Sedat Dilek wrote:
> > > Hi,
> > >
> > > after building Linux v6.4-rc4 I can NOT boot into my Debian GNU/Linux
> > > AMD64 system with root-ext4 (/dev/sdc2 - of course using UUID in
> > > /etc/fstab).
> >
> > I did not find a mailing-list thread for "9828ed3f695a module: error out early
> > on concurrent load of the same module file", so replying here.
> 
> It is this thread:
> 
>    https://lore.kernel.org/lkml/20230524213620.3509138-1-mcgrof@kernel.org/
> 
> which initially proposed a different solution, then that "just reject
> concurrent loads", and after that caused problems, there's yet another
> proposal at
> 
>    https://lore.kernel.org/lkml/CAHk-=wg7ihygotpO9x5a6QJO5oAom9o91==L_Kx-gUHvRYuXiQ@mail.gmail.com/
> 
> although if you want to try out that approach, Johan pointed out a
> missing initialization of a spinlock in that patch in a reply there.
> 
> > Just wanted to highlight this a test case for the next attempt at this
> > fix.
> 
> See above: the next attempt won't be until 6.5, but if you saw the
> failure on your test-cases, it might be a good idea to check out that
> next attempt early..

Thanks, will check those out.

I know that the "Link:" for "mailing-list thread where patch originated"
is mostly useless information [1], but when it comes to quickly reporting
test results on the output of "git bisect", it comes in handy.

[1]: https://lore.kernel.org/all/CAHk-=wgzRUT1fBpuz3xcN+YdsX0SxqOzHWRtj0ReHpUBb5TKbA@mail.gmail.com/