Re: [v3,11/41] mips: reuse asm-generic/barrier.h

From: Peter Zijlstra
Date: Thu Jan 14 2016 - 15:15:55 EST

On Thu, Jan 14, 2016 at 11:42:02AM -0800, Leonid Yegoshin wrote:
> An the only point - please use an appropriate SYNC_* barriers instead of
> heavy bold hammer. That stuff was design explicitly to support the
> requirements of Documentation/memory-barriers.txt

That's madness. That document changes from version to version as to what
we _think_ the actual hardware does. It is _NOT_ a specification.

You cannot design hardware from that. Its incomplete and fails to
specify a bunch of things. It not a mathematically sound definition of a
memory model.

Please stop referring to that document for what a particular barrier
_should_ do. Explain what MIPS does, so we can attempt to integrate
this knowledge with our knowledge of PPC/ARM/Alpha/x86/etc. and improve
upon our understanding of hardware and improve the Linux memory model.