Re: [PATCH 2/2] dax: move writeback calls into the filesystems

I agree the mount option needs to die, and I fully grok the reasoning. What I'm concerned with is that a system using fully-DAX-aware applications is forced to incur the overhead of maintaining *sync semantics, periodic sync(2) in particular, even if it is not relying on those semantics. However, like I said in my other mail, we can solve that with alternate interfaces to persistent memory if that becomes an issue and not require that "disable *sync" capability to come through DAX.