Re: [PATCH v2] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire

Linus Torvalds
2018-07-17T20:14:06Z

On Tue, Jul 17, 2018 at 12:37 PM Alan Stern <stern@rowland.harvard.edu> wrote:
>
> Why not? Instructions are allowed to migrate _into_ critical sections,
> just not _out_ of them. So a store preceding the start of a spinlocked
> region can migrate in and be executed after a load that is inside the
> region.

Hmm, yes of course. But the isync instruction description I found also
talks about the previous instructions being "completed".

But yeah, that obviously can mean just "in the store buffer", not
actually ordered.

Linus