Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261694AbVBXCZo (ORCPT ); Wed, 23 Feb 2005 21:25:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261754AbVBXCZU (ORCPT ); Wed, 23 Feb 2005 21:25:20 -0500 Received: from viper.oldcity.dca.net ([216.158.38.4]:8925 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S261694AbVBXCY7 (ORCPT ); Wed, 23 Feb 2005 21:24:59 -0500 Subject: Re: More latency regressions with 2.6.11-rc4-RT-V0.7.39-02 From: Lee Revell To: Nick Piggin Cc: Hugh Dickins , Ingo Molnar , Andrew Morton , linux-kernel In-Reply-To: <421D2DEE.8070209@yahoo.com.au> References: <1109182061.16201.6.camel@krustophenia.net> <1109187381.3174.5.camel@krustophenia.net> <1109190614.3126.1.camel@krustophenia.net> <421D1171.7070506@yahoo.com.au> <1109207024.4516.6.camel@krustophenia.net> <421D2DEE.8070209@yahoo.com.au> Content-Type: text/plain Date: Wed, 23 Feb 2005 21:24:57 -0500 Message-Id: <1109211897.4831.2.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 27 On Thu, 2005-02-24 at 12:29 +1100, Nick Piggin wrote: > Lee Revell wrote: > > > > IIRC last time I really tested this a few months ago, the worst case > > latency on that machine was about 150us. Currently its 422us from the > > same clear_page_range code path. > > > Well it should be pretty trivial to add a break in there. > I don't think it can get into 2.6.11 at this point though, > so we'll revisit this for 2.6.12 if the clear_page_range > optimisations don't get anywhere. > Agreed, it would be much better to optimize this away than just add a scheduling point. It seems like we could do this lazily. IMHO it's not critical that these latency fixes be merged until the VP feature gets merged, until then people will be using Ingo's patches anyway. Lee - 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/