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Date: Wed, 9 Nov 2016 11:15:20 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Matt Redfearn <matt.redfearn@imgtec.com>
cc: Ralf Baechle <ralf@linux-mips.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
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        Marc Zyngier <marc.zyngier@arm.com>,
        Paul Burton <paul.burton@imgtec.com>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v4 0/4] MIPS: Remote processor driver
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On Wed, 2 Nov 2016, Matt Redfearn wrote:
> The MIPS remote processor driver allows non-Linux firmware to take
> control of and execute on one of the systems VPEs. The CPU must be
> offlined from Linux first. A sysfs interface is created which allows
> firmware to be loaded and changed at runtime. A full description is
> available at [1]. An example firmware that can be used with this driver
> is available at [2].
> 
> This is useful to allow running bare metal code, or an RTOS, on one or
> more CPUs while allowing Linux to continue running on those remaining.

And how is actually guaranteed that these two things are properly seperated
(memory, devices, interrupts etc.) ?

We have rejected attempts to do exactly the same thing on x86 in the
past. There is virtualization and NOHZ_FULL to do it proper and not just
with a horrible hackery.

Thanks,

	tglx