From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030218AbWAXIBZ (ORCPT ); Tue, 24 Jan 2006 03:01:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030231AbWAXIBZ (ORCPT ); Tue, 24 Jan 2006 03:01:25 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:46304 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1030218AbWAXIBZ (ORCPT ); Tue, 24 Jan 2006 03:01:25 -0500 Date: Tue, 24 Jan 2006 09:01:57 +0100 From: Ingo Molnar To: Lee Revell Cc: linux-kernel , Linus Torvalds , "Paul E. McKenney" Subject: Re: RCU latency regression in 2.6.16-rc1 Message-ID: <20060124080157.GA25855@elte.hu> References: <1138089139.2771.78.camel@mindpipe> <20060124075640.GA24806@elte.hu> <1138089483.2771.81.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1138089483.2771.81.camel@mindpipe> 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=no 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 * Lee Revell wrote: > On Tue, 2006-01-24 at 08:56 +0100, Ingo Molnar wrote: > > * Lee Revell wrote: > > > > > I ported the latency tracer to 2.6.16 and got this 13ms latency within > > > a few hours. This is a regression from 2.6.15. > > > > > > It appears that RCU can invoke ipv4_dst_destroy thousands of times in > > > a single batch. > > > > could you try the PREEMPT_RCU patch below? > > Sure. If it works do you see this making it in 2.6.16? Otherwise we > still would have a regression... nope, that likely wont make v2.6.16, which is frozen already. Ingo