On 3/22/2018 8:52 AM, Benjamin Herrenschmidt wrote:

quoted

quoted

No, it's not sufficient.

Just to clarify ... barrier() is just a compiler barrier, it means the
compiler will generate things in the order they are written. This isn't
sufficient on archs with an OO memory model, where an actual memory
barrier instruction needs to be emited.

Surprisingly, ARM64 GCC compiler generates a write barrier as
opposed to preventing code reordering.

I was curious if this is an ARM only thing or not. 

-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.