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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 20 Oct 2022 10:14:54 -0700
Message-ID: <CAHk-=whFow9Wd6C8htoRUt5wXbwf1i_qbuArBbhXOPqYsTFvtw@mail.gmail.com>
Subject: Re: [PATCH -mm] -funsigned-char, x86: make struct p4_event_bind::cntr
 signed array
To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     Alexey Dobriyan <adobriyan@gmail.com>, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, mm-commits@vger.kernel.org,
        masahiroy@kernel.org, keescook@chromium.org,
        gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com
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On Thu, Oct 20, 2022 at 9:28 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> Nice catch.
>
> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>

Can we please try to collect these all in one place?

I see that Andrew picked up the original one for -mm, but I think it
would be better if we had one specific place for all of this (one
branch) to collect it all.

I'm actually trying to do a "make allyesconfig" build on x86-64 with
both signed and unsigned char, and trying to see if I can script
something sane to show differences.

Doing the build is easy, but the differences end up being huge just
due to silly constants (ie the whole "one small difference ends up
changing layout, which then causes hundreds of megs of diff just due
to hex constants in the disassembly changing".

I think the problem is that I tried to do the vmlinux file after
linking to make it easier. Doing the individual object files
separately would probably have been a better idea, just to avoid this
kind of relocation offset issues.

There's not a huge amount of pull requests (the week after -rc1 tends
to be quiet for me), so I'll continue to waste my time on this.

                 Linus