Re: [PATCH] doc: Update wake_up() & co. memory-barrier guarantees

Alan Stern
2018-06-26T13:50:01Z

On Tue, 26 Jun 2018, Andrea Parri wrote:

> > > -A write memory barrier is implied by wake_up() and co. if and only if they
> > > -wake something up. The barrier occurs before the task state is cleared, and so
> > > -sits between the STORE to indicate the event and the STORE to set TASK_RUNNING:
> > > +A general memory barrier is executed by wake_up() if it wakes something up.
> > > +If it doesn't wake anything up then a memory barrier may or may not be
> > > +executed; you must not rely on it. The barrier occurs before the task state
> > > +is accessed, in part., it sits between the STORE to indicate the event and
> > > +the STORE to set TASK_RUNNING:
> >
> > Minor suggestion: Instead of "in part.", how about "that is"?
> >
> > (I generally find "in part." to be at least a little confusing,
> > probably because "part" is itself a word and "in part" is a
> > reasonably common phrase in English.)
>
> Mmh, the fact is that that "before the task state is accessed" does want
> to include the LOAD from ->state to check for the task state (recall the
> pattern in [1])...; how about if I expand "in part." to "in particular"?

That would be acceptable.

Alan