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 32EE6C352AA for ; Tue, 1 Oct 2019 19:08:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12DC321783 for ; Tue, 1 Oct 2019 19:08:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726590AbfJATIj (ORCPT ); Tue, 1 Oct 2019 15:08:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34834 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725844AbfJATIj (ORCPT ); Tue, 1 Oct 2019 15:08:39 -0400 Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BEBCAE2523 for ; Tue, 1 Oct 2019 19:08:38 +0000 (UTC) Received: by mail-qk1-f200.google.com with SMTP id x77so15616248qka.11 for ; Tue, 01 Oct 2019 12:08:38 -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=tyDOxDob+igviijoSMOJYC51FLEyIymiVWHSujSRqsg=; b=Ae6krNmrgnprByIn8rIlH7+tl/PoLQ0qg5I6boxkYuGhkDKs7kt6lhbAlrsdKHcDzA 0okbKs55mmC/pQFUN1N3pa+BSqgmVQKijDzyIH4NqQql0ki2B5PQOLaxrEchDQlNTNCo b9vlskNNcjqCZg/r8KAmGzTu9Eo+XFzFbcu1C1HZdi7uKcHcr5HtOsILkdIKXC9Pb01z NoimrpLB7MmX280vRjrl8iv+xNKEdGW48m+n1AOOVC4CykU48V+haVgl9G2u/OBnuxVl 0aRhxT20JN68LeLg9eOUgNhOD8tnr/dEy6Rf0nx3FkZQAvxivkn5mDNlUMI8Q5zlth1L hzmA== X-Gm-Message-State: APjAAAWAmk2VtboIjvsMwnQ7cScAY6dPmDrsPZwUmRP0sgTVxJOVVh2U hHUvjVW6IjFnA1Bb4LZlcocXDl3Y1AUnATDo5oPiwmATJ/HtYTjyfTjpbePSuMKOA2xRHUw3nw/ xoU38GhfHhjA0kBKTaV52dSBA X-Received: by 2002:a05:620a:7ca:: with SMTP id 10mr7940566qkb.410.1569956918112; Tue, 01 Oct 2019 12:08:38 -0700 (PDT) X-Google-Smtp-Source: APXvYqxqlzM9Ty0JvR982/ZKv1347lkHYUf56yBEMeBfEE56A9YdRL50Yn8F7mKtdi+zcUYu2r/EBA== X-Received: by 2002:a05:620a:7ca:: with SMTP id 10mr7940534qkb.410.1569956917887; Tue, 01 Oct 2019 12:08:37 -0700 (PDT) Received: from redhat.com (bzq-79-176-40-226.red.bezeqint.net. [79.176.40.226]) by smtp.gmail.com with ESMTPSA id n42sm10811959qta.31.2019.10.01.12.08.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Oct 2019 12:08:36 -0700 (PDT) Date: Tue, 1 Oct 2019 15:08:24 -0400 From: "Michael S. Tsirkin" To: Alexander Duyck Cc: David Hildenbrand , Alexander Duyck , virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, dave.hansen@intel.com, linux-kernel@vger.kernel.org, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, mgorman@techsingularity.net, vbabka@suse.cz, osalvador@suse.de, yang.zhang.wz@gmail.com, pagupta@redhat.com, konrad.wilk@oracle.com, nitesh@redhat.com, riel@surriel.com, lcapitulino@redhat.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com Subject: Re: [PATCH v11 0/6] mm / virtio: Provide support for unused page reporting Message-ID: <20191001144331-mutt-send-email-mst@kernel.org> References: <20191001152441.27008.99285.stgit@localhost.localdomain> <7233498c-2f64-d661-4981-707b59c78fd5@redhat.com> <1ea1a4e11617291062db81f65745b9c95fd0bb30.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1ea1a4e11617291062db81f65745b9c95fd0bb30.camel@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 01, 2019 at 09:21:46AM -0700, Alexander Duyck wrote: > I thought what Michal was asking for was what was the benefit of using the > boundary pointer. I added a bit up above and to the description for patch > 3 as on a 32G VM it adds up to about a 18% difference without factoring in > the page faulting and zeroing logic that occurs when we actually do the > madvise. Something maybe worth adding to the log: one disadvantage of the tight integration with the mm core is that only a single reporting device is supported. It's not obvious that more than one is useful though. -- MST