From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 6B84F6B0253 for ; Mon, 2 Oct 2017 17:49:09 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id g10so3264854wrg.2 for ; Mon, 02 Oct 2017 14:49:09 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id b11si8338096wmh.265.2017.10.02.14.49.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Oct 2017 14:49:08 -0700 (PDT) Date: Mon, 2 Oct 2017 14:49:03 -0700 From: Andrew Morton Subject: Re: [PATCH] mm, swap: Make VMA based swap readahead configurable Message-Id: <20171002144903.d58ed6887adfd9dc4cdfd697@linux-foundation.org> In-Reply-To: References: <20170926132129.dbtr2mof35x4j4og@dhcp22.suse.cz> <20170927050401.GA715@bbox> <20170927074835.37m4dclmew5ecli2@dhcp22.suse.cz> <20170927080432.GA1160@bbox> <20170927083512.dydqlqezh5polggb@dhcp22.suse.cz> <20170927131511.GA338@bgram> <20170927132241.tshup6kcwe5pcxek@dhcp22.suse.cz> <20170927134117.GB338@bgram> <20170927135034.yatxlhvunawzmcar@dhcp22.suse.cz> <20170927141008.GA1278@bgram> <20170927141723.bixcum3fler7q4w5@dhcp22.suse.cz> <87mv5f8wkj.fsf@yhuang-dev.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Huang, Ying" , Michal Hocko , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , Rik van Riel , Shaohua Li , Hugh Dickins , Fengguang Wu , Tim Chen On Mon, 2 Oct 2017 08:45:40 -0700 Dave Hansen wrote: > On 09/27/2017 06:02 PM, Huang, Ying wrote: > > I still think there may be a performance regression for some users > > because of the change of the algorithm and the knobs, and the > > performance regression can be resolved via setting the new knob. But I > > don't think there will be a functionality regression. Do you agree? > > A performance regression is a regression. I don't understand why we are > splitting hairs as to what kind of regression it is. > Yes. Ying, please find us a way of avoiding any disruption to existing system setups. One which doesn't require that the operator perform a configuration change to restore prior behaviour/performance. And please let's get this done well in advance of the 4.14 release. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org