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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 30F3CC34047 for ; Wed, 19 Feb 2020 14:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0693E24670 for ; Wed, 19 Feb 2020 14:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726672AbgBSOjQ (ORCPT ); Wed, 19 Feb 2020 09:39:16 -0500 Received: from outbound-smtp63.blacknight.com ([46.22.136.252]:47071 "EHLO outbound-smtp63.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726518AbgBSOjQ (ORCPT ); Wed, 19 Feb 2020 09:39:16 -0500 X-Greylist: delayed 370 seconds by postgrey-1.27 at vger.kernel.org; Wed, 19 Feb 2020 09:39:14 EST Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp63.blacknight.com (Postfix) with ESMTPS id B6A34FB021 for ; Wed, 19 Feb 2020 14:33:03 +0000 (GMT) Received: (qmail 26706 invoked from network); 19 Feb 2020 14:33:03 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.18.57]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 19 Feb 2020 14:33:03 -0000 Date: Wed, 19 Feb 2020 14:33:00 +0000 From: Mel Gorman To: Alexander Duyck Cc: kvm@vger.kernel.org, david@redhat.com, mst@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, 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, alexander.h.duyck@linux.intel.com, vbabka@suse.cz, osalvador@suse.de Subject: Re: [PATCH v17 3/9] mm: Add function __putback_isolated_page Message-ID: <20200219143300.GR3466@techsingularity.net> References: <20200211224416.29318.44077.stgit@localhost.localdomain> <20200211224624.29318.89287.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20200211224624.29318.89287.stgit@localhost.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Feb 11, 2020 at 02:46:24PM -0800, Alexander Duyck wrote: > From: Alexander Duyck > > There are cases where we would benefit from avoiding having to go through > the allocation and free cycle to return an isolated page. > > Examples for this might include page poisoning in which we isolate a page > and then put it back in the free list without ever having actually > allocated it. > > This will enable us to also avoid notifiers for the future free page > reporting which will need to avoid retriggering page reporting when > returning pages that have been reported on. > > Acked-by: David Hildenbrand > Signed-off-by: Alexander Duyck Ok, the prior code that used post_alloc_hook to make the isolated page seem like a normally allocated page followed by a free seems strange anyway. As well as being expensive, isolated pages can end up on the per-cpu lists which is probably not what is desired. I *think* what you've done is ok so Acked-by: Mel Gorman -- Mel Gorman SUSE Labs