From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261561AbVFENuG (ORCPT ); Sun, 5 Jun 2005 09:50:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261564AbVFENuG (ORCPT ); Sun, 5 Jun 2005 09:50:06 -0400 Received: from mx2.elte.hu ([157.181.151.9]:39588 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S261561AbVFENuB (ORCPT ); Sun, 5 Jun 2005 09:50:01 -0400 Date: Sun, 5 Jun 2005 15:49:16 +0200 From: Ingo Molnar To: Esben Nielsen Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Inaky Perez-Gonzalez , Daniel Walker , Oleg Nesterov Subject: Re: [patch] Real-Time Preemption, plist fixes Message-ID: <20050605134916.GA20721@elte.hu> References: <20050605082616.GA26824@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 * Esben Nielsen wrote: > [...] In extreme load situations we could end up with a lot of waiters > on mmap_sem forinstance. what do you mean by extreme load. Extreme number of RT tasks, or extreme number of tasks altogether? The sorted-list implementation i had in -RT had all non-RT tasks handled in an O(1) way - the O(N) component was for adding RT tasks (removal was O(1)). so the question is - can we have an extreme (larger than 140) number of RT tasks? If yes, why are they all RT - they can have no expectation of good latencies with a possible load factor of 140! Ingo