Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262884AbVCWJD7 (ORCPT ); Wed, 23 Mar 2005 04:03:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262885AbVCWJD7 (ORCPT ); Wed, 23 Mar 2005 04:03:59 -0500 Received: from mx1.elte.hu ([157.181.1.137]:20188 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S262884AbVCWJDz (ORCPT ); Wed, 23 Mar 2005 04:03:55 -0500 Date: Wed, 23 Mar 2005 10:03:41 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: "Paul E. McKenney" , Linux-kernel , Esben Nielsen Subject: Re: [patch] Real-Time Preemption, -RT-2.6.12-rc1-V0.7.41-07 Message-ID: <20050323090341.GA7960@elte.hu> References: <20050322054345.GB1296@us.ibm.com> <20050322072413.GA6149@elte.hu> <20050322092331.GA21465@elte.hu> <20050322093201.GA21945@elte.hu> <20050322100153.GA23143@elte.hu> <20050322112856.GA25129@elte.hu> <20050323061601.GE1294@us.ibm.com> <20050323063317.GB31626@elte.hu> <20050323071604.GA32712@elte.hu> <1111566593.14156.2.camel@nspc0585.nedstat.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1111566593.14156.2.camel@nspc0585.nedstat.nl> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 925 Lines: 22 * Peter Zijlstra wrote: > > i think the 'migrate read-count' method is not adequate either, because > > all callbacks queued within an RCU read section must be called after the > > lock has been dropped - while with the migration method CPU#1 would be > > free to process callbacks queued in the RCU read section still active on > > CPU#2. > > how about keeping the rcu callback list in process context and only > splice it to a global (per cpu) list on rcu_read_unlock? hm, that would indeed solve this problem. It would also solve the grace period problem: all callbacks in the global (per-CPU) list are immediately processable. Paul? Ingo - 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/