Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932544AbVJaVu2 (ORCPT ); Mon, 31 Oct 2005 16:50:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932537AbVJaVu2 (ORCPT ); Mon, 31 Oct 2005 16:50:28 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:17859 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S932544AbVJaVu1 (ORCPT ); Mon, 31 Oct 2005 16:50:27 -0500 Date: Mon, 31 Oct 2005 22:50:44 +0100 From: Ingo Molnar To: Hugh Dickins Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, tytso@us.ibm.com, sripathi@in.ibm.com, dipankar@in.ibm.com, oleg@tv-sign.ru Subject: Re: [RFC,PATCH] RCUify single-thread case of clock_gettime() Message-ID: <20051031215044.GA20926@elte.hu> References: <20051031174416.GA2762@us.ibm.com> <20051031195425.GA14806@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=disabled SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1214 Lines: 30 * Hugh Dickins wrote: > On Mon, 31 Oct 2005, Ingo Molnar wrote: > > * Hugh Dickins wrote: > > > > > > Not my area at all, but this looks really dodgy to me, Paul: > > > could you explain it further? > > > > the patch below (included in the -rt tree) is the prerequisite. That's > > what Paul's "requires RCU on task_struct" comment refers to. > > Thanks, Ingo: Sorry, Paul: I missed that it was an -rt patch: Ignore > me. btw., since the RCU-task-struct thing is beneficial to upstream SMP kernels (even without any preempt option enabled), it should be considered for upstream too. The tasklist_lock is one of our last remaining monolithic and globally-bouncing locks. The patch i attached to the previous mail is against the upstream kernel and implements the RCU-task-struct logic, without any PREEMPT_RT dependency. (the -rt tree is a collection of various preemption related patches, not just PREEMPT_RT) 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/