From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751048AbVHLGfZ (ORCPT ); Fri, 12 Aug 2005 02:35:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751150AbVHLGfZ (ORCPT ); Fri, 12 Aug 2005 02:35:25 -0400 Received: from mx2.elte.hu ([157.181.151.9]:65245 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S1751048AbVHLGfY (ORCPT ); Fri, 12 Aug 2005 02:35:24 -0400 Date: Fri, 12 Aug 2005 08:36:00 +0200 From: Ingo Molnar To: Lee Revell Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, dipankar@in.ibm.com, rusty@au1.ibm.com, bmark@us.ibm.com, Thomas Gleixner , Andrew Morton Subject: Re: [RFC,PATCH] Use RCU to protect tasklist for unicast signals Message-ID: <20050812063600.GC13397@elte.hu> References: <20050810171145.GA1945@us.ibm.com> <20050811095634.GA19342@elte.hu> <1123812057.26878.9.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1123812057.26878.9.camel@mindpipe> 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 * Lee Revell wrote: > Doesn't this fix the longest latency we were seeing with > PREEMPT_DESKTOP, I don't have a trace handy but the upshot was "signal > delivery must remain atomic on !PREEMPT_RT"? yes - although Paul's patch converts only a portion of the signal code to RCU-read-lock, so i'd expect there to be other latencies too. Might be worth a test (once we've sorted out the HRT build bugs). Ingo