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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 74F02C35242 for ; Wed, 12 Feb 2020 00:19:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2F6B92082F for ; Wed, 12 Feb 2020 00:19:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="jDUI8gnV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F6B92082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9DBB46B037C; Tue, 11 Feb 2020 19:19:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 98C8F6B037D; Tue, 11 Feb 2020 19:19:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8A2376B037E; Tue, 11 Feb 2020 19:19:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0179.hostedemail.com [216.40.44.179]) by kanga.kvack.org (Postfix) with ESMTP id 70B556B037C for ; Tue, 11 Feb 2020 19:19:30 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0D3A8181AEF10 for ; Wed, 12 Feb 2020 00:19:30 +0000 (UTC) X-FDA: 76479566100.15.map37_6ffee32993514 X-HE-Tag: map37_6ffee32993514 X-Filterd-Recvd-Size: 4151 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Wed, 12 Feb 2020 00:19:29 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4DF1206D6; Wed, 12 Feb 2020 00:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581466768; bh=w9zWL4o2HAKds3LpMaqdUwP5gcbuhFqnYi3cxNKDsT0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jDUI8gnVwIzyE5ZFs/uNqKwQrQ7QYN7VBXMtsDohVxxnUH9dh6iOM9LNSKNDF+PXy OYBfkKCBSzhwo4Qeu5YfTRLcG3vguj5B13PRIz8r4WtTtF8DxP/ERu9ib+3bchW2vw kTJmZR3eqlWwTQQMHDMiUrmOGETamNHy+pzbRERk= Date: Tue, 11 Feb 2020 16:19:27 -0800 From: Andrew Morton To: Alexander Duyck Cc: Alexander Duyck , kvm@vger.kernel.org, david@redhat.com, mst@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mgorman@techsingularity.net, 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: <20200211161927.1068232d044e892782aef9ae@linux-foundation.org> In-Reply-To: References: <20200211224416.29318.44077.stgit@localhost.localdomain> <20200211150510.ca864143284c8ccaa906f524@linux-foundation.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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.