linux-kernel - Re: [PATCH 1/8] Compiler attributes: GCC function alignment workarounds

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Message-ID: <CANiq72kEow5hBBfzSL7=yihgU1Xm=DiKqeV7A8p8h_qW_f18cg@mail.gmail.com>
Date:   Sun, 15 Jan 2023 22:32:38 +0100
From:   Miguel Ojeda <miguel.ojeda.sandonis@...il.com>
To:     Mark Rutland <mark.rutland@....com>
Cc:     linux-arm-kernel@...ts.infradead.org, catalin.marinas@....com,
        lenb@...nel.org, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org, mhiramat@...nel.org,
        ndesaulniers@...gle.com, ojeda@...nel.org, peterz@...radead.org,
        rafael.j.wysocki@...el.com, revest@...omium.org,
        robert.moore@...el.com, rostedt@...dmis.org, will@...nel.org
Subject: Re: [PATCH 1/8] Compiler attributes: GCC function alignment workarounds

On Fri, Jan 13, 2023 at 1:49 PM Mark Rutland <mark.rutland@....com> wrote:
>
> It turns out that was a red herring; GCC is actually implicitly marking the
> abort() function as cold, and as Linux's implementation happened to be marked
> as weak I assumed that was the culprit.

That and your previous message probably explains probably why I
couldn't reproduce it.

Thanks a lot for all the details -- the `cold` issue is reproducible
since gcc 4.6 at least: https://godbolt.org/z/PoxazzT9T

The `abort` case appears to happen since gcc 8.1.

Cheers,
Miguel