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References: <20231122100212.94327-1-lizhe.67@bytedance.com>
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From:   Doug Anderson <dianders@chromium.org>
Date:   Wed, 22 Nov 2023 08:03:50 -0800
Message-ID: <CAD=FV=Vb12_OKY5Vu1ZWTG6+innP5PkEnHFRPrwj2kOKnHCmag@mail.gmail.com>
Subject: Re: [PATCH v2] softlockup: serialized softlockup's log
To:     lizhe.67@bytedance.com
Cc:     akpm@linux-foundation.org, pmladek@suse.com,
        lecopzer.chen@mediatek.com, kernelfans@gmail.com,
        linux-kernel@vger.kernel.org, lizefan.x@bytedance.com
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Hi,

On Wed, Nov 22, 2023 at 2:02=E2=80=AFAM <lizhe.67@bytedance.com> wrote:
>
> From: Li Zhe <lizhe.67@bytedance.com>
>
> If multiple CPUs trigger softlockup at the same time with
> 'softlockup_all_cpu_backtrace=3D0', the softlockup's logs will appear
> staggeredly in dmesg, which will affect the viewing of the logs for
> developer. Since the code path for outputting softlockup logs is not
> a kernel hotspot and the performance requirements for the code are
> not strict, locks are used to serialize the softlockup log output to
> improve the readability of the logs.
>
> Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
> ---
> Changelogs:
>
> v1->v2:
> - define the lock outside the scope of function
> - add precondition 'softlockup_all_cpu_backtrace=3D0' in commit message
>
>  kernel/watchdog.c | 4 ++++
>  1 file changed, 4 insertions(+)

This seems like a useful improvement to me and the code looks good.

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