From: Oleg Nesterov <oleg@redhat.com>
To: Nicholas Mc Guire <der.herr@hofr.at>
Cc: Davidlohr Bueso <dave@stgolabs.net>,
paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
waiman.long@hp.com, peterz@infradead.org,
raghavendra.kt@linux.vnet.ibm.com
Subject: Re: BUG: spinlock bad magic on CPU#0, migration/0/9
Date: Thu, 12 Feb 2015 20:39:05 +0100 [thread overview]
Message-ID: <20150212193905.GB28499@redhat.com> (raw)
In-Reply-To: <20150212193210.GA7244@opentech.at>
On 02/12, Nicholas Mc Guire wrote:
>
> On Thu, 12 Feb 2015, Oleg Nesterov wrote:
>
> > --- x/kernel/sched/completion.c
> > +++ x/kernel/sched/completion.c
> > @@ -274,7 +274,7 @@ bool try_wait_for_completion(struct comp
> > * first without taking the lock so we can
> > * return early in the blocking case.
> > */
> > - if (!ACCESS_ONCE(x->done))
> > + if (!READ_ONCE(x->done))
> > return 0;
> >
> from looking at compiler.h I don't think that there would be a difference
> between ACCESS_ONCE() and READ_ONCE() in this case
Yes, this is unrelated "while at it" cosmetic change, now that we have
READ_ONCE() it makes more sense in this case.
Oleg.
next prev parent reply other threads:[~2015-02-12 19:41 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-12 0:34 BUG: spinlock bad magic on CPU#0, migration/0/9 Paul E. McKenney
2015-02-12 3:15 ` Davidlohr Bueso
2015-02-12 3:43 ` Paul E. McKenney
2015-02-12 17:28 ` Oleg Nesterov
2015-02-12 17:41 ` Oleg Nesterov
2015-02-12 17:58 ` Davidlohr Bueso
2015-02-12 19:10 ` Nicholas Mc Guire
2015-02-12 19:37 ` Oleg Nesterov
2015-02-12 21:27 ` Oleg Nesterov
2015-02-13 18:17 ` Nicholas Mc Guire
2015-02-13 18:53 ` Oleg Nesterov
2015-02-14 8:35 ` Nicholas Mc Guire
2015-02-14 14:00 ` Oleg Nesterov
2015-02-12 19:59 ` Davidlohr Bueso
2015-02-12 19:32 ` Nicholas Mc Guire
2015-02-12 19:39 ` Oleg Nesterov [this message]
2015-02-12 19:59 ` [PATCH] sched/completion: completion_done() should serialize with complete() Oleg Nesterov
2015-02-13 21:09 ` Paul E. McKenney
2015-02-13 21:56 ` Davidlohr Bueso
2015-02-13 22:02 ` Davidlohr Bueso
2015-02-16 8:21 ` Peter Zijlstra
2015-02-16 16:51 ` Oleg Nesterov
2015-02-18 17:06 ` [tip:sched/core] sched/completion: Serialize completion_done() " tip-bot for Oleg Nesterov
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