From mboxrd@z Thu Jan 1 00:00:00 1970 From: Reza Arbab Subject: Re: [PATCH v4 4/5] mm: make processing of movable_node arch-specific Date: Tue, 25 Oct 2016 19:49:29 -0500 Message-ID: <20161026004929.h6v54dhehk4yvmwm@arbab-vm> References: <1475778995-1420-1-git-send-email-arbab@linux.vnet.ibm.com> <1475778995-1420-5-git-send-email-arbab@linux.vnet.ibm.com> <235f2d20-cf84-08df-1fb4-08ee258fdc52@gmail.com> <20161025155507.37kv5akdlgo6m2be@arbab-laptop.austin.ibm.com> <112504e9-561d-e0da-7a40-73996c678b56@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <112504e9-561d-e0da-7a40-73996c678b56@gmail.com> Sender: owner-linux-mm@kvack.org To: Balbir Singh Cc: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Rob Herring , Frank Rowand , Andrew Morton , Bharata B Rao , Nathan Fontenot , Stewart Smith , Alistair Popple , "Aneesh Kumar K.V" , Tang Chen , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-mm@kvack.org List-Id: devicetree@vger.kernel.org On Wed, Oct 26, 2016 at 09:34:18AM +1100, Balbir Singh wrote: >I still believe we need your changes, I was wondering if we've tested >it against normal memory nodes and checked if any memblock >allocations end up there. Michael showed me some memblock >allocations on node 1 of a two node machine with movable_node The movable_node option is x86-only. Both of those nodes contain normal memory, so allocations on both are allowed. >> Longer; if you use "movable_node", x86 can identify these nodes at >> boot. They call memblock_mark_hotplug() while parsing the SRAT. Then, >> when the zones are initialized, those markings are used to determine >> ZONE_MOVABLE. >> >> We have no analog of this SRAT information, so our movable nodes can >> only be created post boot, by hotplugging and explicitly onlining >> with online_movable. > >Is this true for all of system memory as well or only for nodes >hotplugged later? As far as I know, power has nothing like the SRAT that tells us, at boot, which memory is hotpluggable. So there is nothing to wire the movable_node option up to. Of course, any memory you hotplug afterwards is, by definition, hotpluggable. So we can still create movable nodes that way. -- Reza Arbab -- 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