From: Andi Kleen <andi@firstfloor.org>
To: Christoph Lameter <cl@linux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@infradead.org>,
Ingo Molnar <mingo@elte.hu>, Andi Kleen <andi@firstfloor.org>,
Nick Piggin <npiggin@kernel.dk>
Subject: Re: [PATCH] atomic: add atomic_inc_not_zero_hint()
Date: Mon, 15 Nov 2010 15:39:07 +0100 [thread overview]
Message-ID: <20101115143907.GN7269@basil.fritz.box> (raw)
In-Reply-To: <alpine.DEB.2.00.1011150821000.19175@router.home>
> > atomic_read() and atomic_cmpxchg(). We tried prefetchw() and it was a
> > performance drop. It was with only 16 cpus contending on neighbour
>
> Does prefetchw work? Andi claims that prefetchw is not working on
> x86 and I doubt that you ran tests on Itanium.
AMD supports it due to their MOESI protocol, but it's not supported
in MESIF as used by Intel QPI. The kernel maps it on Intel to
ordinary prefetch.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2010-11-15 14:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-05 16:53 [PATCH] atomic: add atomic_inc_not_zero_hint() Eric Dumazet
2010-11-05 17:20 ` Andrew Morton
2010-11-05 18:00 ` Eric Dumazet
2010-11-05 18:08 ` Andrew Morton
2010-11-05 18:20 ` Eric Dumazet
2010-11-05 18:28 ` Andrew Morton
2010-11-05 19:20 ` Eric Dumazet
2010-11-05 19:39 ` Andrew Morton
2010-11-05 19:46 ` Eric Dumazet
2010-11-05 19:51 ` Paul E. McKenney
2010-11-12 19:14 ` Christoph Lameter
2010-11-13 22:26 ` Paul E. McKenney
2010-11-15 13:57 ` Christoph Lameter
2010-11-15 14:07 ` Andi Kleen
2010-11-15 14:16 ` Christoph Lameter
2010-11-15 14:17 ` Eric Dumazet
2010-11-15 14:25 ` Christoph Lameter
2010-11-15 14:39 ` Andi Kleen [this message]
2010-11-15 14:47 ` Eric Dumazet
2010-11-05 18:40 ` Paul E. McKenney
2010-11-05 19:12 ` Eric Dumazet
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