From: Andi Kleen <ak@suse.de>
To: Christoph Lameter <clameter@sgi.com>
Cc: Dong Feng <middle.fengdong@gmail.com>,
Paul Mackerras <paulus@samba.org>,
linux-kernel@vger.kernel.org
Subject: Re: Why Semaphore Hardware-Dependent?
Date: Sun, 27 Aug 2006 23:39:08 +0200 [thread overview]
Message-ID: <200608272339.08092.ak@suse.de> (raw)
In-Reply-To: <Pine.LNX.4.64.0608271404260.22510@schroedinger.engr.sgi.com>
On Sunday 27 August 2006 23:05, Christoph Lameter wrote:
> On Sun, 27 Aug 2006, Andi Kleen wrote:
>
> > rwsems don't -- there are two flavours: a generic spinlock'ed one and a
> > complicated atomic based one that only works on some architectures.
> > As far as I know nobody has demonstrated a clear performance increase
> > from the first so it might be possible to switch all to the generic
> > implementation.
>
> Yup that would be the major issue.I'd be interested to see some tests in
> that area.
x86-64 always uses the spinlocked version (vs i386 using the atomic one)
and I haven't heard of anybody complaining.
-Andi
next prev parent reply other threads:[~2006-08-27 21:39 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-27 19:22 Why Semaphore Hardware-Dependent? Dong Feng
2006-08-27 20:52 ` Andi Kleen
2006-08-27 21:05 ` Christoph Lameter
2006-08-27 21:39 ` Andi Kleen [this message]
2006-08-27 22:14 ` Christoph Lameter
2006-08-28 0:18 ` Paul Mackerras
2006-08-28 5:14 ` Chris Wedgwood
2006-08-28 5:21 ` Christoph Lameter
2006-08-28 5:56 ` Jan Engelhardt
2006-08-28 12:35 ` linux-os (Dick Johnson)
2006-08-28 7:23 ` Andi Kleen
2006-08-29 1:00 ` Paul Mackerras
2006-08-28 7:30 ` Arjan van de Ven
2006-08-29 1:18 ` Nick Piggin
2006-08-29 6:07 ` Andi Kleen
2006-09-13 17:54 ` Nick Piggin
2006-08-29 10:05 ` David Howells
2006-08-29 10:56 ` Andi Kleen
2006-08-29 17:40 ` Andrew Morton
2006-08-29 19:10 ` Benjamin LaHaise
2006-08-29 15:56 ` Christoph Lameter
2006-08-29 16:20 ` Ralf Baechle
2006-08-29 16:25 ` David Howells
2006-08-29 16:28 ` Christoph Lameter
2006-08-29 16:57 ` David Howells
2006-08-29 16:53 ` Ralf Baechle
2006-08-29 16:58 ` Geert Uytterhoeven
2006-08-29 17:22 ` Andi Kleen
2006-08-29 17:36 ` Christoph Lameter
2006-08-29 18:18 ` Andi Kleen
2006-08-29 18:30 ` David Howells
2006-08-29 18:33 ` Andi Kleen
2006-08-29 18:56 ` David Howells
2006-08-29 18:41 ` Christoph Lameter
2006-09-13 18:04 ` Nick Piggin
2006-09-13 18:07 ` Christoph Lameter
2006-09-13 18:13 ` Nick Piggin
2006-09-13 18:16 ` Christoph Lameter
2006-09-13 18:50 ` David Howells
2006-09-13 19:25 ` Nick Piggin
2006-09-14 11:41 ` David Howells
2006-09-14 15:27 ` Nick Piggin
2006-09-14 15:38 ` Nick Piggin
2006-09-15 8:59 ` David Howells
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