Re: [PATCH v4 0/4] MIPS: Remote processor driver

[Thomas Gleixner]

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