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Subject: Re: new warning on sysrq kernel crash trigger
To: Ani Sinha <ani@arista.com>, Paul McKenney <paulmck@linux.vnet.ibm.com>
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Cc: Randy Dunlap <rdunlap@infradead.org>, Richard Weinberger <richard@nod.at>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Ivan Delalande <colona@arista.com>, fruggeri <fruggeri@arista.com>
From: Rik van Riel <riel@redhat.com>
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Date: Mon, 14 Dec 2015 12:07:08 -0500
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On 12/14/2015 11:24 AM, Ani Sinha wrote:
> Rik, any comments?

Another good option is to simply ignore this warning, or drop
the rcu_read_lock before doing the alt-syrsq-c action.

After all, alt-sysrq-c is "crash the system, take a crash dump",
which is not an action the system ever returns from.

static struct sysrq_key_op sysrq_crash_op = {
        .handler        = sysrq_handle_crash,
        .help_msg       = "crash(c)",
        .action_msg     = "Trigger a crash",
        .enable_mask    = SYSRQ_ENABLE_DUMP,
};

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