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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 22FB4C34048 for ; Tue, 18 Feb 2020 16:37:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05CC9208C4 for ; Tue, 18 Feb 2020 16:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbgBRQhr (ORCPT ); Tue, 18 Feb 2020 11:37:47 -0500 Received: from mga18.intel.com ([134.134.136.126]:50244 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726399AbgBRQhr (ORCPT ); Tue, 18 Feb 2020 11:37:47 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Feb 2020 08:37:46 -0800 X-IronPort-AV: E=Sophos;i="5.70,456,1574150400"; d="scan'208";a="224189171" Received: from ahduyck-desk1.jf.intel.com ([10.7.198.76]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Feb 2020 08:37:46 -0800 Message-ID: <31383bb111737c9f8ffbb1e6e4446cb4fd620a53.camel@linux.intel.com> Subject: Re: [PATCH v17 0/9] mm / virtio: Provide support for free page reporting From: Alexander Duyck To: mgorman@techsingularity.net 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 Date: Tue, 18 Feb 2020 08:37:46 -0800 In-Reply-To: <20200211161927.1068232d044e892782aef9ae@linux-foundation.org> References: <20200211224416.29318.44077.stgit@localhost.localdomain> <20200211150510.ca864143284c8ccaa906f524@linux-foundation.org> <20200211161927.1068232d044e892782aef9ae@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.5 (3.32.5-1.fc30) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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. Thanks. - Alex