From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752299AbdFLGhS (ORCPT ); Mon, 12 Jun 2017 02:37:18 -0400 Received: from mx2.suse.de ([195.135.220.15]:37199 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752155AbdFLGhR (ORCPT ); Mon, 12 Jun 2017 02:37:17 -0400 Date: Mon, 12 Jun 2017 08:37:13 +0200 From: Michal Hocko To: Wei Yang Cc: Andrew Morton , linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Andrea Arcangeli , Reza Arbab , Yasuaki Ishimatsu , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML Subject: Re: [PATCH] mm, memory_hotplug: support movable_node for hotplugable nodes Message-ID: <20170612063713.GC4145@dhcp22.suse.cz> References: <20170608122318.31598-1-mhocko@kernel.org> <20170611014535.GA6206@WeideMBP.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170611014535.GA6206@WeideMBP.lan> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 11-06-17 09:45:35, Wei Yang wrote: > On Thu, Jun 08, 2017 at 02:23:18PM +0200, Michal Hocko wrote: > >From: Michal Hocko > > > >movable_node kernel parameter allows to make hotplugable NUMA > >nodes to put all the hotplugable memory into movable zone which > >allows more or less reliable memory hotremove. At least this > >is the case for the NUMA nodes present during the boot (see > >find_zone_movable_pfns_for_nodes). > > > >This is not the case for the memory hotplug, though. > > > > echo online > /sys/devices/system/memory/memoryXYZ/status > > > >will default to a kernel zone (usually ZONE_NORMAL) unless the > >particular memblock is already in the movable zone range which is not > >the case normally when onlining the memory from the udev rule context > >for a freshly hotadded NUMA node. The only option currently is to have a > >special udev rule to echo online_movable to all memblocks belonging to > >such a node which is rather clumsy. Not the mention this is inconsistent > >as well because what ended up in the movable zone during the boot will > >end up in a kernel zone after hotremove & hotadd without special care. > > > > A kernel zone here means? Which is the counterpart in zone_type? or a > combination of several zone_type? Any zone but < ZONE_HIGHMEM. The specific zone depends on the placement. But it is ZONE_NORMAL in most situations. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 633406B0279 for ; Mon, 12 Jun 2017 02:37:17 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id v104so20850687wrb.6 for ; Sun, 11 Jun 2017 23:37:17 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id n50si9075396wrn.230.2017.06.11.23.37.16 for (version=TLS1 cipher=AES128-SHA bits=128/128); Sun, 11 Jun 2017 23:37:16 -0700 (PDT) Date: Mon, 12 Jun 2017 08:37:13 +0200 From: Michal Hocko Subject: Re: [PATCH] mm, memory_hotplug: support movable_node for hotplugable nodes Message-ID: <20170612063713.GC4145@dhcp22.suse.cz> References: <20170608122318.31598-1-mhocko@kernel.org> <20170611014535.GA6206@WeideMBP.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170611014535.GA6206@WeideMBP.lan> Sender: owner-linux-mm@kvack.org List-ID: To: Wei Yang Cc: Andrew Morton , linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Andrea Arcangeli , Reza Arbab , Yasuaki Ishimatsu , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML On Sun 11-06-17 09:45:35, Wei Yang wrote: > On Thu, Jun 08, 2017 at 02:23:18PM +0200, Michal Hocko wrote: > >From: Michal Hocko > > > >movable_node kernel parameter allows to make hotplugable NUMA > >nodes to put all the hotplugable memory into movable zone which > >allows more or less reliable memory hotremove. At least this > >is the case for the NUMA nodes present during the boot (see > >find_zone_movable_pfns_for_nodes). > > > >This is not the case for the memory hotplug, though. > > > > echo online > /sys/devices/system/memory/memoryXYZ/status > > > >will default to a kernel zone (usually ZONE_NORMAL) unless the > >particular memblock is already in the movable zone range which is not > >the case normally when onlining the memory from the udev rule context > >for a freshly hotadded NUMA node. The only option currently is to have a > >special udev rule to echo online_movable to all memblocks belonging to > >such a node which is rather clumsy. Not the mention this is inconsistent > >as well because what ended up in the movable zone during the boot will > >end up in a kernel zone after hotremove & hotadd without special care. > > > > A kernel zone here means? Which is the counterpart in zone_type? or a > combination of several zone_type? Any zone but < ZONE_HIGHMEM. The specific zone depends on the placement. But it is ZONE_NORMAL in most situations. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org