Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755373Ab1DGWF2 (ORCPT ); Thu, 7 Apr 2011 18:05:28 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:60433 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754888Ab1DGWF1 (ORCPT ); Thu, 7 Apr 2011 18:05:27 -0400 Date: Thu, 7 Apr 2011 15:05:24 -0700 From: "Paul E. McKenney" To: Mathieu Desnoyers Cc: Huang Ying , huang ying , Andrew Morton , Andi Kleen , "lenb@kernel.org" , "linux-kernel@vger.kernel.org" , Linus Torvalds Subject: Re: About lock-less data structure patches Message-ID: <20110407220524.GK2262@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <4D93DB49.3060205@intel.com> <20110401213748.GA26543@Krystal> <4D96AEAE.2010800@intel.com> <20110404155328.GA13390@Krystal> <20110405044227.GA20013@Krystal> <20110406014824.GB32321@Krystal> <4D9D1DF0.6030704@intel.com> <20110407183206.GB6104@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110407183206.GB6104@Krystal> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1970 Lines: 55 On Thu, Apr 07, 2011 at 02:32:06PM -0400, Mathieu Desnoyers wrote: > * Huang Ying (ying.huang@intel.com) wrote: > > On 04/06/2011 09:48 AM, Mathieu Desnoyers wrote: > > > * huang ying (huang.ying.caritas@gmail.com) wrote: > > [snip] > > >>>> > > >>>> OK. I will change the comments, adding these semantics explanation. > > >>>> The user should be warned :) > > >>> > > >>> Yes, that makes sense. After this generalization step, if you're ok with > > >>> this, we could aim at moving the implementation from a stack to a queue > > >>> and provide fifo semantic rather than lifo, so that other users (e.g. > > >>> call_rcu in the kernel) can start benefiting from it. Just to be clear... Currently, call_rcu() works on a per-CPU basis, so that it can simply disable interrupts and then do the queuing non-atomically. However, should it be necessary to cross-queue RCU callbacks in order to avoid ever executing an RCU callback on a given CPU, then something like this might become useful. Thanx, Paul > > >> I think that is good to move from stack to queue. > > >> > > >> I will send out changed lock-less data structure patchset soon. And > > >> we can continue to work on the new lock-less queue at the same time. > > > > > > Sounds like a very good plan! Thanks! > > > > Maybe you can send out your lock-less queue patches, so we can work on that. > > Yep, let's wait until your implementation is finalized and merged, and > then ping me again so I can cook up a RFC patch turning llist into a > queue, if it's OK with you. > > Thanks, > > Mathieu > > > > > Best Regards, > > Huang Ying > > -- > Mathieu Desnoyers > Operating System Efficiency R&D Consultant > EfficiOS Inc. > http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/