Date: Thu, 3 Dec 2015 21:31:59 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: mingo@kernel.org, oleg@redhat.com, linux-kernel@vger.kernel.org,
        paulmck@linux.vnet.ibm.com, boqun.feng@gmail.com, corbet@lwn.net,
        mhocko@kernel.org, dhowells@redhat.com, torvalds@linux-foundation.org,
        will.deacon@arm.com, waiman.long@hpe.com, pjt@google.com
Subject: Re: [PATCH 3/4] locking: Introduce smp_cond_acquire()
Message-ID: <20151203203159.GW17308@twins.programming.kicks-ass.net>
References: <20151203124010.627312076@infradead.org>
 <20151203124339.552838970@infradead.org>
 <20151203194139.GA5650@linux-uzut.site>
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On Thu, Dec 03, 2015 at 11:41:39AM -0800, Davidlohr Bueso wrote:

> >+#define smp_cond_acquire(cond)	do {		\
> >+	while (!(cond))				\
> >+		cpu_relax();			\
> >+	smp_rmb(); /* ctrl + rmb := acquire */	\
> >+} while (0)
> 
> So this hides the fact that we actually are waiting on the cond, as opposed
> to conditional acquiring. Could it be renamed to something like smp_waitcond_acquire()?

Right, I'm conflicted about that. On the one hand you're right, on the
other hand we spin-wait so the next person will want it called
smp_spin_wait_cond_acquire(), also it gets terribly long either way :/

bike-shed away I imagine.
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