Re: [PATCH v3 2/4] membarrier: Create Documentation/scheduler/membarrier.rst

[Andrea Parri <parri.andrea@gmail.com>]

Hi Randy,

> > +MEMBARRIER_CMD_{PRIVATE,GLOBAL}_EXPEDITED - Architecture requirements
> > +=====================================================================
> > +
> > +Memory barriers before updating rq->curr
> > +----------------------------------------
> > +
> > +The command requires each architecture to have a full memory barrier after
> > +coming from user-space, before updating rq->curr.  This barrier is implied
> > +by the sequence rq_lock(); smp_mb__after_spinlock() in __schedule().  The
> > +barrier matches a full barrier in the proximity of the membarrier system
> > +call exit, cf. membarrier_{private,global}_expedited().
> > +
> 
> What does "The command" refer to above and below, please?

The term was meant to refer to any of MEMBARRIER_CMD_PRIVATE_EXPEDITED and
MEMBARRIER_CMD_GLOBAL_EXPEDITED (from the section title); FWIW, this seems
to align with the terminology adopted in MEMBARRIER(2) for example.

Mmh, unless I get a better idea, I'll expand those occurrences to:

  "The commands MEMBARRIER_CMD_PRIVATE_EXPEDITED and MEMBARRIER_CMD_GLOBAL_EXPEDIDED
   require [...]"

  Andrea