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Date: Tue, 1 Jul 2014 16:55:23 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>,
        Lai Jiangshan <laijs@cn.fujitsu.com>,
        Peter Zijlstra <peterz@infradead.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 0/2] rcu: uninline rcu_lock_acquire() and
	rcu_lock_release()
Message-ID: <20140701145523.GA12547@redhat.com>
References: <20140630161837.GA15873@redhat.com> <20140630202420.GG4603@linux.vnet.ibm.com>
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On 06/30, Paul E. McKenney wrote:
>
> On Mon, Jun 30, 2014 at 06:18:37PM +0200, Oleg Nesterov wrote:
> > Hello,
> >
> > May be correct this time ;) Based on paulmck/linux-rcu.git rcu/next.
> >
> > 2/2 is new and hopefully trivial. But! the numbers look suspiciously
> > good, I do not understand where does the difference come from...
>
> Probably from rcu_dereference_raw() and rcu_dereference_check(..., 1).  ;-)

Yes, sure, this was the motivation for the patch. But I didn't expect the
50k difference ;)

OK, I understand now. I forgot that every list_for_each_rcu/list_entry_rcu
has rcu_dereference_raw().

> Queued and kicked off testing, both mine and (indirectly) Fengguang's.

Thanks!

Oleg.