Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261578AbVCXRvt (ORCPT ); Thu, 24 Mar 2005 12:51:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262641AbVCXRvs (ORCPT ); Thu, 24 Mar 2005 12:51:48 -0500 Received: from mx1.elte.hu ([157.181.1.137]:22912 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S261578AbVCXRvr (ORCPT ); Thu, 24 Mar 2005 12:51:47 -0500 Date: Thu, 24 Mar 2005 18:51:27 +0100 From: Ingo Molnar To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Esben Nielsen Subject: Re: [patch] Real-Time Preemption, -RT-2.6.12-rc1-V0.7.41-07 Message-ID: <20050324175127.GA25108@elte.hu> References: <20050322100153.GA23143@elte.hu> <20050322112856.GA25129@elte.hu> <20050323061601.GE1294@us.ibm.com> <20050323063317.GB31626@elte.hu> <20050324052854.GA1298@us.ibm.com> <20050324053456.GA14494@elte.hu> <20050324113912.GA20911@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-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: 1259 Lines: 26 * Steven Rostedt wrote: > > but i think i like the 'partial owner' (or rather 'owner pending') > > technique a bit better, because it controls concurrency explicitly, and > > it would thus e.g. allow another trick: when a new owner 'steals' a lock > > from another in-flight task, then we could 'unwakeup' that in-flight > > thread which could thus avoid two more context-switches on e.g. SMP > > systems: hitting the CPU and immediately blocking on the lock. (But this > > is a second-phase optimization which needs some core scheduler magic as > > well, i guess i'll be the one to code it up.) > > Darn! It seemed like fun to implement. I may do it myself anyway on my > kernel just to understand your implementation even better. feel free to implement the whole thing. Unscheduling a task should be done carefully, for obvious reasons. (I've implemented it once 1-2 years ago for a different purpose, to unschedule ksoftirqd - it ought to be somewhere in the lkml archives.) 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/