Hi Leif,

I think I got it. Thank you very much.

-----Original Message-----
From: Leif Lindholm [mailto:leif.lindholm@linaro.org]
Sent: 2014-5-1 () 19:32
To: Kelvin K. Li
Cc: linaro-dev@lists.linaro.org
Subject: Re: : why is the the smp_mb() in arm64's barrier.h "dmb ish"?

On Thu, May 01, 2014 at 06:49:44PM +0800, KelvinKLi@via-alliance.com wrote:
> Another questions:
> In Arm V8 Architecture Reference Manualthere is an example (see beblow) to explain the shareability attribute of clusters. It is easy to know: each cluster is corresponding to a Inner shareable domain; the two cluster comprise a Outer shareable domain.

The ARM ARM describes the architectural requirements for a system to
be able to work correctly. Specific implementations can add further
abilities within the scope of this. And Linux can then have additional
requirements for how to enable SMP/HMP..

> So, how does the big.LITTLE HMP system treat two clusters as a Inner shareable domain

Example for Cortex-A53: