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=ham 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 5F5E0C43381 for ; Mon, 18 Feb 2019 18:01:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BA7B21736 for ; Mon, 18 Feb 2019 18:01:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391803AbfBRSBq (ORCPT ); Mon, 18 Feb 2019 13:01:46 -0500 Received: from mail-qk1-f196.google.com ([209.85.222.196]:35642 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389649AbfBRSBp (ORCPT ); Mon, 18 Feb 2019 13:01:45 -0500 Received: by mail-qk1-f196.google.com with SMTP id w204so10505653qka.2 for ; Mon, 18 Feb 2019 10:01:45 -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=n+lUg0FjYKjVVNOiBok5yuGwwfOjuaZM6OCfyQUBVQU=; b=U6g5U+HhqHa1d4/Z3CEe0eiQ5hSCRFahP6/l8oCu3X006ZJ9QCuFjpcKDOC6SNA/Il C8faS8yD/u+BN18Xw+0pFR7GxaN0x2/mvIqTgYG1b+uOVjS1y7OZvsObSeTozAhfVKLG VIOIwGeptjNyRA8/MlQ6Slf6hUdxf+VjbNTNd8I6V4glkwHmsw6/MWxT36z0kRfrCcTd Zzln1l7rFAUs4xXjDDfSL7nELMoIGMtN/gbNK2orEi1+iY+5hd8wGtQa/QbKa7tjqPhd x7uiGPl77I8OtuFARF/0/zlet4Bd3L5Q92B06cJA1tuE6wOkZEyfbfKQkCw1LcEiR6tP BYkQ== X-Gm-Message-State: AHQUAubKb/YlVNS7p18h7CgBWwnl6GNFhLeS7r7xxYcqrRuWjDeWyeXZ 3LAtDyHJbTMlBUB3BeK0uY74WA== X-Google-Smtp-Source: AHgI3IZTyy+MV/wZQfYIyq6KSc0oc0+h3xBl7Ogtr4q/u7Lm4aax6aNJccYgDytciZLV2ydkm/p3mg== X-Received: by 2002:a37:80b:: with SMTP id 11mr17314698qki.131.1550512904816; Mon, 18 Feb 2019 10:01:44 -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 z63sm7503030qkc.42.2019.02.18.10.01.43 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 18 Feb 2019 10:01:43 -0800 (PST) Date: Mon, 18 Feb 2019 13:01:41 -0500 From: "Michael S. Tsirkin" To: Alexander Duyck Cc: David Hildenbrand , Nitesh Narayan Lal , kvm list , LKML , 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 v8 0/7] KVM: Guest Free Page Hinting Message-ID: <20190218125552-mutt-send-email-mst@kernel.org> References: <20190204201854.2328-1-nitesh@redhat.com> <20190218114601-mutt-send-email-mst@kernel.org> <44740a29-bb14-e6e6-2992-98d0ae58e994@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, Feb 18, 2019 at 09:31:13AM -0800, Alexander Duyck wrote: > > Optimization of space comes with a price (here: execution time). > > One thing to keep in mind though is that if you are already having to > pull pages in and out of swap on the host in order be able to provide > enough memory for the guests the free page hinting should be a > significant win in terms of performance. Absolutely and I think that's the point of the hinting right? To cut out swap/IO on the host. -- MST