From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932787AbXCXStb (ORCPT ); Sat, 24 Mar 2007 14:49:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932833AbXCXSta (ORCPT ); Sat, 24 Mar 2007 14:49:30 -0400 Received: from mail.clusterfs.com ([206.168.112.78]:45043 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932787AbXCXSt3 (ORCPT ); Sat, 24 Mar 2007 14:49:29 -0400 From: Nikita Danilov MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17925.29368.942606.691598@gargle.gargle.HOWL> Date: Sat, 24 Mar 2007 21:49:28 +0300 To: Ingo Molnar Cc: Nick Piggin , Linux Kernel Mailing List , Ravikiran G Thirumalai Subject: Re: [rfc][patch] queued spinlocks (i386) In-Reply-To: <20070324172959.GB542@elte.hu> References: <20070323085910.GA11577@wotan.suse.de> <20070323100418.GA30740@elte.hu> <20070323103243.GE11577@wotan.suse.de> <17925.18904.820106.145029@gargle.gargle.HOWL> <20070324172959.GB542@elte.hu> X-Mailer: VM 7.17 under 21.5 (patch 17) "chayote" (+CVS-20040321) XEmacs Lucid X-SystemSpamProbe: GOOD 0.0000545 e97e24faf1f643fc1b1008a7a0fa6782 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar writes: > > * Nikita Danilov wrote: > > > Indeed, this technique is very well known. E.g., > > http://citeseer.ist.psu.edu/anderson01sharedmemory.html has a whole > > section (3. Local-spin Algorithms) on them, citing papers from the > > 1990 onward. > > that is a cool reference! So i'd suggest to do (redo?) the patch based > on those concepts and that terminology and not use 'queued spinlocks' There is some old version: http://namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p06-locallock.patch http://namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p07-locallock-bkl.patch http://namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p08-locallock-zone.patch http://namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p0b-atomic_dec_and_locallock.patch http://namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p0c-locallock-dcache.patch This version retains original spin-lock interface (i.e., no additional "queue link" pointer is passed to the locking function). As a result, lock data structure contains an array of NR_CPU counters, so it's only suitable for global statically allocated locks. > that are commonly associated with MS's stuff. And as a result the > contended case would be optimized some more via local-spin algorithms. > (which is not a key thing for us, but which would be nice to have > nevertheless) > > Ingo Nikita.