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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 52803C76195 for ; Wed, 17 Jul 2019 07:39:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F2B9C21743 for ; Wed, 17 Jul 2019 07:39:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2B9C21743 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 514D56B0005; Wed, 17 Jul 2019 03:39:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4C5026B0008; Wed, 17 Jul 2019 03:39:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3B4368E0001; Wed, 17 Jul 2019 03:39:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id DD8926B0005 for ; Wed, 17 Jul 2019 03:39:02 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id b12so17463741eds.14 for ; Wed, 17 Jul 2019 00:39:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=6QszZE0XvjntTJ134Z4d4YLDD1JPaC0EPAQ3GCn2UaM=; b=LGhnZCjaZjPNXffcbr76dSKBuGSKyXD0sYX0fbS19jHfHmOv+/TtpCcVEkvEPgEzuK WeBjAR8W13QIwz8CgVX3d/PETyUJdSjIHBnp0G+75wPi8wk4VrrNP/Nuh7IDQAryNuSX s/Kc9EVhsR9gQzRnF03yIUlY6/Yvn68bgxL8v7daxjvIP+GQtrUYEdEdjbPaEpzS8E/u VwAIz9oPZisfFvFTF9kPXhQkxZyAefOnsB16DYZzePrwoNVXF1+1KIRVwWTwV7bO4vwk wlxPNj9m9TKTWj8PSVbNPJ2MwaqyVDjn0/l9bhske4WXVDTFvBzJEHWkz/MSjHH9AQui nTTA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Gm-Message-State: APjAAAVVnkXwWKLOGurPVXrtYDqpoa4J+6shkMl2UShGt/X5CsNyvuXr fPD8P0LCtvzopognyaOHJWKhsESQWu688vTwMILc7goJRavAWNAuM65hkyfuXVBBVVhP7yDgmSv wdFDsk3s4P+jx+GfDiE1H5dZxqCvQB6CVATNDh4NxrEdMabHApjoqmt/b6IPJe+9/3Q== X-Received: by 2002:a17:907:20db:: with SMTP id qq27mr29459928ejb.30.1563349142474; Wed, 17 Jul 2019 00:39:02 -0700 (PDT) X-Google-Smtp-Source: APXvYqzCbQwYDbNmVjwyWC+ib5+HNOxjmOOk9O/U4MDEm0ua0kmRKq1qxhYlAhR4SyJRqfekArzG X-Received: by 2002:a17:907:20db:: with SMTP id qq27mr29459870ejb.30.1563349141511; Wed, 17 Jul 2019 00:39:01 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1563349141; cv=none; d=google.com; s=arc-20160816; b=ymg7VH7sgnoD4xzurpWn7v/WfEdORjGEytO9iuuI97XOd2dgEoTjmYwDYxajJpW3a0 FZ/t4lsu+8HBZxogkexEa8Bw+CxRJfV2Q+Vp2+71Vr5ThYbB0T5FtOKYoJQVMNl6gT7O Z7k7FfehLRMIuVS7Pqcyjj5+zp+ZVz7sPxurjFh1jED2OY18wG8HSZ51Nr32JxjuIDiw xQjHxXnQd7EFmX0HV88vySRAZvw0PAyAwAyE5sZ9rErkAAuH9io3A45uIMDGr7sKwD3q CBtjXNPB4pDISxW+Jq+PH2I53azt6loyJ+ixs583k+tiDxy+RLG+VAQfSghv/i8q+QR7 8PwQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=6QszZE0XvjntTJ134Z4d4YLDD1JPaC0EPAQ3GCn2UaM=; b=hFPXI8iwZKQZIbSrrEyb6n6hZRs/WfwKnq73jkSziKhvYS7mX1zyztJt9nf5d1e3qY ztKIW05B8QfZwQcpYVnxQPxYUVsTSX47WEGNco14LtF9b5AjmIQo+/VsHv6ZMnBZXPwq wzshwEVkCoQSD+PJJTgb6PPiQGbpD4XHWwoOv18wc3WqlC09Vjp5IN73s8h405/9C0tx dwTpDoh4wxuSQX2aPwYoH0H+6sN+bu36obNRUGFrAIsPBahU4rvPHClwMS17KUGBcToZ u9rsuFXlHWQ3o7BwCVUGV+x3+yupa5jBKn9teVNcf3iniRR99tXoZ8DkkxKMcZysddd5 yaXA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=osalvador@suse.de Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id d16si14255368ede.18.2019.07.17.00.39.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Jul 2019 00:39:01 -0700 (PDT) Received-SPF: pass (google.com: domain of osalvador@suse.de designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D197EADBF; Wed, 17 Jul 2019 07:39:00 +0000 (UTC) Date: Wed, 17 Jul 2019 09:38:58 +0200 From: Oscar Salvador To: Dan Williams Cc: "Aneesh Kumar K.V" , Andrew Morton , David Hildenbrand , Pavel Tatashin , Michal Hocko , Linux MM , Linux Kernel Mailing List Subject: Re: [PATCH 2/2] mm,memory_hotplug: Fix shrink_{zone,node}_span Message-ID: <20190717073853.GA22253@linux> References: <20190715081549.32577-1-osalvador@suse.de> <20190715081549.32577-3-osalvador@suse.de> <87tvbne0rd.fsf@linux.ibm.com> <1563225851.3143.24.camel@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 16, 2019 at 07:28:54PM -0700, Dan Williams wrote: > This makes it more clear that the problem is with the "start_pfn == > pfn" check relative to subsections, but it does not clarify why it > needs to clear pfn_valid() before calling shrink_zone_span(). > Sections were not invalidated prior to shrink_zone_span() in the > pre-subsection implementation and it seems all we need is to keep the > same semantic. I.e. skip the range that is currently being removed: Yes, as I said in my reply to Aneesh, that is the other way I thought when fixing it. The reason I went this way is because it seemed more reasonable and natural to me that pfn_valid() would just return the next active sub-section. I just though that we could leverage the fact that we can deactivate a sub-section before scanning for the next one. On a second thought, the changes do not outweight the case, being the first fix enough and less intrusive, so I will send a v2 with that instead. -- Oscar Salvador SUSE L3