From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70E6DC10F0E for ; Mon, 15 Apr 2019 11:48:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EBAE2073F for ; Mon, 15 Apr 2019 11:48:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555328916; bh=SpeobVWB2QsYqn/FmtnInJKobU60wZglh1sCEizkgRk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=xdgX7lN/51znW9osHdp19k4INQgpiM9K8xBbKa40w8Y2QLDdNERVamI3HoZkdl5dD seAG3TSPnBzDYrMLVH07aGFnVfGO57vzEDP0liecxZ2baKJgnrEcz+GEYwBSPwLA7H PLJmAfk5fcHjnLi10Xu/NF0yyYXqi4DD5RDiQBiw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727318AbfDOLse (ORCPT ); Mon, 15 Apr 2019 07:48:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:48722 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726319AbfDOLse (ORCPT ); Mon, 15 Apr 2019 07:48:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 37C77AE8B; Mon, 15 Apr 2019 11:48:33 +0000 (UTC) Date: Mon, 15 Apr 2019 13:48:32 +0200 From: Michal Hocko To: David Rientjes Cc: Linus Torvalds , Andrea Arcangeli , mgorman@techsingularity.net, Vlastimil Babka , ying.huang@intel.com, s.priebe@profihost.ag, Linux List Kernel Mailing , alex.williamson@redhat.com, lkp@01.org, kirill@shutemov.name, Andrew Morton , zi.yan@cs.rutgers.edu Subject: Re: [LKP] [mm] ac5b2c1891: vm-scalability.throughput -61.3% regression Message-ID: <20190415114832.GK3366@dhcp22.suse.cz> References: <64a4aec6-3275-a716-8345-f021f6186d9b@suse.cz> <20181204104558.GV23260@techsingularity.net> <20181205204034.GB11899@redhat.com> <20181205233632.GE11899@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 06-12-18 15:43:26, David Rientjes wrote: > On Wed, 5 Dec 2018, Linus Torvalds wrote: > > > > Ok, I've applied David's latest patch. > > > > > > I'm not at all objecting to tweaking this further, I just didn't want > > > to have this regression stand. > > > > Hmm. Can somebody (David?) also perhaps try to state what the > > different latency impacts end up being? I suspect it's been mentioned > > several times during the argument, but it would be nice to have a > > "going forward, this is what I care about" kind of setup for good > > default behavior. > > > > I'm in the process of writing a more complete test case for this but I > benchmarked a few platforms based solely on remote hugepages vs local > small pages vs remote hugepages. My previous numbers were based on data > from actual workloads. Has this materialized into anything we can use? We plan to discuss this particular topic at the LSFMM this year and it would be great to have something to play with. I am quite nervious that we have left quite a common case with a bad performance based on a complain that we cannot really reproduce so it is really hard to move on. -- Michal Hocko SUSE Labs