Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230616150618.6073-1-pmladek@suse.com> <20230616150618.6073-2-pmladek@suse.com>
In-Reply-To: <20230616150618.6073-2-pmladek@suse.com>
From:   Doug Anderson <dianders@chromium.org>
Date:   Fri, 16 Jun 2023 09:44:01 -0700
Message-ID: <CAD=FV=XUWnjCAjZKb5wYcGhC=T8+hoUr+1junoH5ognge1aZHg@mail.gmail.com>
Subject: Re: [PATCH v2 1/6] watchdog/hardlockup: Sort hardlockup detector
 related config values a logical way
To:     Petr Mladek <pmladek@suse.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        kgdb-bugreport@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        Nicholas Piggin <npiggin@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linuxppc-dev@lists.ozlabs.org,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        sparclinux@vger.kernel.org,
        "David S . Miller" <davem@davemloft.net>,
        linux-perf-users@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi,

On Fri, Jun 16, 2023 at 8:06=E2=80=AFAM Petr Mladek <pmladek@suse.com> wrot=
e:
>
> There are four possible variants of hardlockup detectors:
>
>   + buddy: available when SMP is set.
>
>   + perf: available when HAVE_HARDLOCKUP_DETECTOR_PERF is set.
>
>   + arch-specific: available when HAVE_HARDLOCKUP_DETECTOR_ARCH is set.
>
>   + sparc64 special variant: available when HAVE_NMI_WATCHDOG is set
>         and HAVE_HARDLOCKUP_DETECTOR_ARCH is not set.
>
> Only one hardlockup detector can be compiled in. The selection is done
> using quite complex dependencies between several CONFIG variables.
> The following patches will try to make it more straightforward.
>
> As a first step, reorder the definitions of the various CONFIG variables.
> The logical order is:
>
>    1. HAVE_* variables define available variants. They are typically
>       defined in the arch/ config files.
>
>    2. HARDLOCKUP_DETECTOR y/n variable defines whether the hardlockup
>       detector is enabled at all.
>
>    3. HARDLOCKUP_DETECTOR_PREFER_BUDDY y/n variable defines whether
>       the buddy detector should be preferred over the perf one.
>       Note that the arch specific variants are always preferred when
>       available.
>
>    4. HARDLOCKUP_DETECTOR_PERF/BUDDY variables define whether the given
>       detector is enabled in the end.
>
>    5. HAVE_HARDLOCKUP_DETECTOR_NON_ARCH and HARDLOCKUP_DETECTOR_NON_ARCH
>       are temporary variables that are going to be removed in
>       a followup patch.
>
> This is a preparation step for further cleanup. It will change the logic
> without shuffling the definitions.
>
> This change temporary breaks the C-like ordering where the variables are
> declared or defined before they are used. It is not really needed for
> Kconfig. Also the following patches will rework the logic so that
> the ordering will be C-like in the end.
>
> The patch just shuffles the definitions. It should not change the existin=
g
> behavior.
>
> Signed-off-by: Petr Mladek <pmladek@suse.com>
> ---
>  lib/Kconfig.debug | 112 +++++++++++++++++++++++-----------------------
>  1 file changed, 56 insertions(+), 56 deletions(-)

Reviewed-by: Douglas Anderson <dianders@chromium.org>