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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Changbin Du <changbin.du@gmail.com>
Cc:     Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        hpa@zytor.com, x86@kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, Changbin Du <changbin.du@gmail.com>
Subject: Re: [PATCH] x86/nmi: remove the irqwork from long duration nmi handler
In-Reply-To: <20200101072017.82990-1-changbin.du@gmail.com>
References: <20200101072017.82990-1-changbin.du@gmail.com>
Date:   Thu, 09 Jan 2020 21:55:51 +0100
Message-ID: <877e20bb8o.fsf@nanos.tec.linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
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Changbin Du <changbin.du@gmail.com> writes:

> First, printk is NMI context safe now since the safe printk has been
> implemented. The safe printk already has an irqwork to make NMI context
> safe.
>
> Second, the NMI irqwork actually does not work if a NMI handler causes
> panic by watchdog timeout. This NMI irqwork have no chance to run in such
> case, while the safe printk will flush its per-cpu buffer before panic.
>
> Signed-off-by: Changbin Du <changbin.du@gmail.com>

Looks about right.

Acked-by: Thomas Gleixner <tglx@linutronix.de>