[Arm-netbook] ARM big.LITTLE Processing

[luke.leighton]

On Wed, Oct 10, 2012 at 10:11 PM, Alain Williams <addw at phcomp.co.uk> wrote:
> Basically on one chip you have a Cortex-A15 MPCore and a Cortex-A7 core.
> >From the programming viewpoint these look the same (same registers, instruction
> set, ...) but the A15 is powerful but eats energy, the A7 is slow but uses
> little energy. If the OS is running on the A7 and needs more power it migrates
> itself to the A15 in some 20 microseconds and runs, but faster. When the work is
> done it migrates itself back to the A7.
>
> So: run in the core that is appropriate to the work load & save electricity.

 ... good, eh? :)  nvidia independently came up with something
similar, apparently.

 the only thing i heard is that migrating is at the moment an
all-or-nothing approach.  i don't know if it's possible to migrate
individual tasks.

 l.