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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 08271C34050 for ; Wed, 19 Feb 2020 08:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE5CB2464E for ; Wed, 19 Feb 2020 08:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726648AbgBSItR (ORCPT ); Wed, 19 Feb 2020 03:49:17 -0500 Received: from outbound-smtp62.blacknight.com ([46.22.136.251]:52275 "EHLO outbound-smtp62.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbgBSItR (ORCPT ); Wed, 19 Feb 2020 03:49:17 -0500 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp62.blacknight.com (Postfix) with ESMTPS id 94EFDFA897 for ; Wed, 19 Feb 2020 08:49:15 +0000 (GMT) Received: (qmail 29501 invoked from network); 19 Feb 2020 08:49:15 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.18.57]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 19 Feb 2020 08:49:15 -0000 Date: Wed, 19 Feb 2020 08:49:12 +0000 From: Mel Gorman To: Alexander Duyck Cc: Andrew Morton , Alexander Duyck , kvm@vger.kernel.org, david@redhat.com, mst@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, yang.zhang.wz@gmail.com, pagupta@redhat.com, konrad.wilk@oracle.com, nitesh@redhat.com, riel@surriel.com, willy@infradead.org, lcapitulino@redhat.com, dave.hansen@intel.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, mhocko@kernel.org, vbabka@suse.cz, osalvador@suse.de Subject: Re: [PATCH v17 0/9] mm / virtio: Provide support for free page reporting Message-ID: <20200219084912.GO3466@techsingularity.net> References: <20200211224416.29318.44077.stgit@localhost.localdomain> <20200211150510.ca864143284c8ccaa906f524@linux-foundation.org> <20200211161927.1068232d044e892782aef9ae@linux-foundation.org> <31383bb111737c9f8ffbb1e6e4446cb4fd620a53.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <31383bb111737c9f8ffbb1e6e4446cb4fd620a53.camel@linux.intel.com> 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 Tue, Feb 18, 2020 at 08:37:46AM -0800, Alexander Duyck wrote: > On Tue, 2020-02-11 at 16:19 -0800, Andrew Morton wrote: > > On Tue, 11 Feb 2020 15:55:31 -0800 Alexander Duyck wrote: > > > > > On the host I just have to monitor /proc/meminfo and I can see the > > > difference. I get the following results on the host, in the enabled case > > > it takes about 30 seconds for it to settle into the final state since I > > > only report page a bit at a time: > > > Baseline/Applied > > > MemTotal: 131963012 kB > > > MemFree: 95189740 kB > > > > > > Enabled: > > > MemTotal: 131963012 kB > > > MemFree: 126459472 kB > > > > > > This is what I was referring to with the comment above. I had a test I was > > > running back around the first RFC that consisted of bringing up enough VMs > > > so that there was a bit of memory overcommit and then having the VMs in > > > turn run memhog. As I recall the difference between the two was something > > > like a couple minutes to run through all the VMs as the memhog would take > > > up to 40+ seconds for one that was having to pull from swap while it took > > > only 5 to 7 seconds for the VMs that were all running the page hinting. > > > > > > I had referenced it here in the RFC: > > > https://lore.kernel.org/lkml/20190204181118.12095.38300.stgit@localhost.localdomain/ > > > > > > I have been verifying the memory has been getting freed but didn't feel > > > like the test added much value so I haven't added it to the cover page for > > > a while since the time could vary widely and is dependent on things like > > > the disk type used for the host swap since my SSD is likely faster than > > > spinning rust, but may not be as fast as other SSDs on the market. Since > > > the disk speed can play such a huge role I wasn't comfortable posting > > > numbers since the benefits could vary so widely. > > > > OK, thanks. I'll add the patches to the mm pile. The new > > mm/page_reporting.c is unreviewed afaict, so I guess you own that for > > now ;) > > > > It would be very nice to get some feedback from testers asserting "yes, > > this really helped my workload" but I understand this sort of testing > > is hard to obtain at this stage. > > > > Mel, > > Any ETA on when you would be available to review these patches? They are > now in Andrew's tree and in linux-next. I am hoping to get any remaining > review from the community sorted out in the next few weeks so I can move > onto focusing on how best to exert pressure on the page cache so that we > can keep the guest memory footprint small. > I hope to get to it soon. I'm trying to finalise a scheduler-related series that reconciles NUMA and CPU balancing and it's occupying much of my attention available for mainline development :( -- Mel Gorman SUSE Labs