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=-8.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 87397C433E1 for ; Mon, 24 Aug 2020 10:39:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4C4DB2067C for ; Mon, 24 Aug 2020 10:39:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C4DB2067C 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 B7E8B6B0002; Mon, 24 Aug 2020 06:39:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B0AD26B0005; Mon, 24 Aug 2020 06:39:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A9236B0006; Mon, 24 Aug 2020 06:39:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id 7CB366B0002 for ; Mon, 24 Aug 2020 06:39:22 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 37B3D1EE6 for ; Mon, 24 Aug 2020 10:39:22 +0000 (UTC) X-FDA: 77185115364.12.drink73_4a114a527052 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 0497F1800E900 for ; Mon, 24 Aug 2020 10:39:21 +0000 (UTC) X-HE-Tag: drink73_4a114a527052 X-Filterd-Recvd-Size: 2355 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Mon, 24 Aug 2020 10:39:21 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4CF8EAC98; Mon, 24 Aug 2020 10:39:50 +0000 (UTC) Date: Mon, 24 Aug 2020 12:39:18 +0200 From: Oscar Salvador To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Andrew Morton , Wei Yang , Baoquan He , Pankaj Gupta Subject: Re: [PATCH v2 02/10] mm/memory_hotplug: enforce section granularity when onlining/offlining Message-ID: <20200824103917.GB6315@linux> References: <20200819175957.28465-1-david@redhat.com> <20200819175957.28465-3-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819175957.28465-3-david@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 0497F1800E900 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 Wed, Aug 19, 2020 at 07:59:49PM +0200, David Hildenbrand wrote: > Already two people (including me) tried to offline subsections, because > the function looks like it can deal with it. But we really can only > online/offline full sections that are properly aligned (e.g., we can only > mark full sections online/offline via SECTION_IS_ONLINE). > > Add a simple safety net to document the restriction now. Current users > (core and powernv/memtrace) respect these restrictions. It's been a while since I looked at sub-section handling stuff so sorry to ask this, but was it true that we can hot-{remove,add} sub-section granularity, while we can only online /offline on section granularity? > > Acked-by: Michal Hocko > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Wei Yang > Cc: Baoquan He > Cc: Pankaj Gupta > Cc: Oscar Salvador > Signed-off-by: David Hildenbrand Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3