Hi Kelvin.
On 30 April 2014 10:52, KelvinKLi@via-alliance.com wrote:
In arch/arm64/include/asm/barrier.h, there is the definition of smp_mb()/smp_rmb()/smp_wmb() for arm64. I noticed that all the 3 macors are using “dmb ishxx”, which is only affect the cluster of the CPU executing the instruction.
This is incorrect.
But in the big.LITTLE system, there will be 2 cluster. So the smp_mb()/smp_rmb()/smp_wmb() cannot affect all the CPU in the system.
Yes, they do.
In a big.LITTLE HMP system, all participating CPUs are part of the inner-shareable domain.
Regards,
Leif