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 F2E43C10F05 for ; Mon, 1 Apr 2019 14:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8D5A208E4 for ; Mon, 1 Apr 2019 14:48:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728650AbfDAOsA (ORCPT ); Mon, 1 Apr 2019 10:48:00 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:33830 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728019AbfDAOsA (ORCPT ); Mon, 1 Apr 2019 10:48:00 -0400 Received: by mail-qt1-f196.google.com with SMTP id k2so11164741qtm.1 for ; Mon, 01 Apr 2019 07:47:59 -0700 (PDT) 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=Nt8nCkiL/lmRXg5mImkQVFR8ydDkGxqOHtXpP9B9HMI=; b=p6BmT3usqoedl3gL1c/0RqW30YEEdPf4JnXJTCdhYLuBZQsEU39SGDJtH0SrC+b+1i gHfrjy6FdBuGstgOpv4sKbG2wrc+hnlN1B6iiM+RZKTNhFVRaVKmaaoVj7cjtEOZeGIa cqpe4xNJN0M/e0AVzcMRN1/8EGzr5W6t3TCq2erPbBZVD6mb/CG4QGUgRkz0CIJTG0L+ JbGJjjcORENLaGHwYP6NHuPT4bBLp+TdfOZxXDQir3/RMGTaIQrA2T7cJ1XEd88+I01N UigFDQR7C1O7g/jvfVqTisXaSJeo/p/Jp3kmFvV4s3qJiTNxvEDeDOo5PAryRJ6pXhzR a9jQ== X-Gm-Message-State: APjAAAUnKlhS6B0TynW9LbI8uavFH/mJ7JVtiaWmwXa1F0wyhkTeTaPw 25yavTa87Ne2/ANYEdlQorCuNQ== X-Google-Smtp-Source: APXvYqwzMFehCXyKpzmyvfdZzFoZbM7plT1F+hAXxH2SANmhbRwnjoxXtZ7V+qdz4DDg0+b8E538ew== X-Received: by 2002:a0c:d1a6:: with SMTP id e35mr53515321qvh.174.1554130079126; Mon, 01 Apr 2019 07:47:59 -0700 (PDT) Received: from redhat.com (pool-173-76-246-42.bstnma.fios.verizon.net. [173.76.246.42]) by smtp.gmail.com with ESMTPSA id u16sm7752118qtc.84.2019.04.01.07.47.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 01 Apr 2019 07:47:58 -0700 (PDT) Date: Mon, 1 Apr 2019 10:47:56 -0400 From: "Michael S. Tsirkin" To: David Hildenbrand Cc: Nitesh Narayan Lal , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pbonzini@redhat.com, lcapitulino@redhat.com, pagupta@redhat.com, wei.w.wang@intel.com, yang.zhang.wz@gmail.com, riel@surriel.com, dodgen@google.com, konrad.wilk@oracle.com, dhildenb@redhat.com, aarcange@redhat.com, alexander.duyck@gmail.com Subject: Re: On guest free page hinting and OOM Message-ID: <20190401104608-mutt-send-email-mst@kernel.org> References: <20190329084058-mutt-send-email-mst@kernel.org> <20190329104311-mutt-send-email-mst@kernel.org> <7a3baa90-5963-e6e2-c862-9cd9cc1b5f60@redhat.com> <20190329125034-mutt-send-email-mst@kernel.org> <20190401073007-mutt-send-email-mst@kernel.org> <29e11829-c9ac-a21b-b2f1-ed833e4ca449@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 Mon, Apr 01, 2019 at 04:11:42PM +0200, David Hildenbrand wrote: > > The interesting thing is most probably: Will the hinting size usually be > > reasonable small? At least I guess a guest with 4TB of RAM will not > > suddenly get a hinting size of hundreds of GB. Most probably also only > > something in the range of 1GB. But this is an interesting question to > > look into. > > > > Also, if the admin does not care about performance implications when > > already close to hinting, no need to add the additional 1Gb to the ram size. > > "close to OOM" is what I meant. Problem is, host admin is the one adding memory. Guest admin is the one that knows about performance. > > -- > > Thanks, > > David / dhildenb