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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 8F4A0C43381 for ; Fri, 8 Mar 2019 02:32:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68C252081B for ; Fri, 8 Mar 2019 02:32:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726579AbfCHCcL (ORCPT ); Thu, 7 Mar 2019 21:32:11 -0500 Received: from mail-qt1-f194.google.com ([209.85.160.194]:40020 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726423AbfCHCcL (ORCPT ); Thu, 7 Mar 2019 21:32:11 -0500 Received: by mail-qt1-f194.google.com with SMTP id f11so2429257qti.7 for ; Thu, 07 Mar 2019 18:32:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=iF16cgfp12yoaJJ5MQem592rInh+vH6ZaUK3pS+44v4=; b=BIUTrOk83AkkjzBwLwtNegPwH6T2pWRMx1U9LeILcka/HfDyGWu601qHV5l7UvMMf1 kgIDF9S/tTOY47F5JlB8dKw3+UjJONhqzOJM4ITmql3PUe5lWbjzikMLVu8PA9WPft91 XGmaEvj3PBEdBhtZsd0PIDz+5VJa4FbspTvEu4KqaJeTxohdRA/SvQaef0NGpUBWfznM 8ViYy2DBQjQdP8pfvGOlf4hN6w257HVy0TQyYJ7GMu6EwN8C/Dfz5vE11IlP/e5c18m8 H7rDtMFuozcAsHouH3Y15UfYc6zL7HnvainSd2yrGRerLYF+V/wYQBuQqNIbIqC7Ym6A 8ZIw== X-Gm-Message-State: APjAAAWU6AsygF7vz0h8jbSPkqhe7LdQfoWoeMISO1RRimqPK4Zmh7yV eTMSSlWvn3K+MYSzpNNZG9jCpA== X-Google-Smtp-Source: APXvYqwFsRg/Gqf8+NEhgHdzJyicZWPFO0RBwKAp8m1NoEf1T1SAM90gXXpZVFq9IrBbWHCt/WLQtA== X-Received: by 2002:a0c:b485:: with SMTP id c5mr13538580qve.78.1552012330342; Thu, 07 Mar 2019 18:32:10 -0800 (PST) Received: from redhat.com (pool-173-76-246-42.bstnma.fios.verizon.net. [173.76.246.42]) by smtp.gmail.com with ESMTPSA id p10sm2973617qkg.76.2019.03.07.18.32.08 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 07 Mar 2019 18:32:09 -0800 (PST) Date: Thu, 7 Mar 2019 21:32:07 -0500 From: "Michael S. Tsirkin" To: Alexander Duyck Cc: David Hildenbrand , Nitesh Narayan Lal , kvm list , LKML , linux-mm , Paolo Bonzini , lcapitulino@redhat.com, pagupta@redhat.com, wei.w.wang@intel.com, Yang Zhang , Rik van Riel , dodgen@google.com, Konrad Rzeszutek Wilk , dhildenb@redhat.com, Andrea Arcangeli Subject: Re: [RFC][Patch v9 2/6] KVM: Enables the kernel to isolate guest free pages Message-ID: <20190307212845-mutt-send-email-mst@kernel.org> References: <20190306155048.12868-1-nitesh@redhat.com> <20190306155048.12868-3-nitesh@redhat.com> <2d9ae889-a9b9-7969-4455-ff36944f388b@redhat.com> <22e4b1cd-38a5-6642-8cbe-d68e4fcbb0b7@redhat.com> <78b604be-2129-a716-a7a6-f5b382c9fb9c@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 07, 2019 at 02:35:53PM -0800, Alexander Duyck wrote: > The only other thing I still want to try and see if I can do is to add > a jiffies value to the page private data in the case of the buddy > pages. Actually there's one extra thing I think we should do, and that is make sure we do not leave less than X% off the free memory at a time. This way chances of triggering an OOM are lower. > With that we could track the age of the page so it becomes > easier to only target pages that are truly going cold rather than > trying to grab pages that were added to the freelist recently. I like that but I have a vague memory of discussing this with Rik van Riel and him saying it's actually better to take away recently used ones. Can't see why would that be but maybe I remember wrong. Rik - am I just confused? -- MST