Re: [tip:locking/core] futex: Enhance comments in futex_lock_pi() for blocking paths

[Darren Hart <dvhart@infradead.org>]

On Mon, Jul 20, 2015 at 02:59:04PM -0700, Davidlohr Bueso wrote:
> On Mon, 2015-07-20 at 14:24 -0700, Darren Hart wrote:
> > On Mon, Jul 20, 2015 at 03:57:37AM -0700, tip-bot for Davidlohr Bueso wrote:
> > > Commit-ID:  767f509ca11269c2bcd92e3972a93096f2173ac0
> > > Gitweb:     http://git.kernel.org/tip/767f509ca11269c2bcd92e3972a93096f2173ac0
> > > Author:     Davidlohr Bueso <dave@stgolabs.net>
> > > AuthorDate: Mon, 29 Jun 2015 23:26:01 -0700
> > > Committer:  Thomas Gleixner <tglx@linutronix.de>
> > > CommitDate: Mon, 20 Jul 2015 11:45:45 +0200
> > > 
> > > futex: Enhance comments in futex_lock_pi() for blocking paths
> > > 
> > > ... serves a bit better to clarify between blocking
> > > and non-blocking code paths.
> > > 
> > > Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
> > > Cc: Peter Zijlstra <peterz@infradead.org>
> > > Cc: Darren Hart <darren@dvhart.com>
> > > Cc: Davidlohr Bueso <dave@stgolabs.net>
> > > Link: http://lkml.kernel.org/r/1435645562-975-2-git-send-email-dave@stgolabs.net
> > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > > ---
> > >  kernel/futex.c | 11 +++++++++--
> > >  1 file changed, 9 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/kernel/futex.c b/kernel/futex.c
> > > index c4a182f..153eb22 100644
> > > --- a/kernel/futex.c
> > > +++ b/kernel/futex.c
> > > @@ -2268,8 +2268,11 @@ static long futex_wait_restart(struct restart_block *restart)
> > >  /*
> > >   * Userspace tried a 0 -> TID atomic transition of the futex value
> > >   * and failed. The kernel side here does the whole locking operation:
> > > - * if there are waiters then it will block, it does PI, etc. (Due to
> > > - * races the kernel might see a 0 value of the futex too.)
> > > + * if there are waiters then it will block as a consequence of relying
> > > + * on rt-mutexes, it does PI, etc. (Due to races the kernel might see
> > > + * a 0 value of the futex too.).
> > > + *
> > > + * Also serves as futex trylock_pi()'ing, and due semantics.
> > 
> > Hrm, what does 'due' mean here?
> 
> By that I meant respective/corresponding.

Right, OK, read awkwardly to me for some reason.

-- 
Darren Hart
Intel Open Source Technology Center