From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42669) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WwyFg-0002vC-NW for qemu-devel@nongnu.org; Tue, 17 Jun 2014 14:37:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WwyFX-00009p-5R for qemu-devel@nongnu.org; Tue, 17 Jun 2014 14:37:00 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:40749) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WwyFW-00009c-U8 for qemu-devel@nongnu.org; Tue, 17 Jun 2014 14:36:51 -0400 Received: from /spool/local by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Jun 2014 12:36:48 -0600 Date: Tue, 17 Jun 2014 11:36:27 -0700 From: Nishanth Aravamudan Message-ID: <20140617183627.GO16644@linux.vnet.ibm.com> References: <1402905233-26510-1-git-send-email-aik@ozlabs.ru> <539EA7DD.8040306@ozlabs.ru> <20140616205150.GD8629@otherpad.lan.raisama.net> <20140617002500.GL16644@linux.vnet.ibm.com> <20140617013700.GE3222@otherpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140617013700.GE3222@otherpad.lan.raisama.net> Subject: Re: [Qemu-devel] [PATCH 0/7] spapr: rework memory nodes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Alexey Kardashevskiy , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf On 16.06.2014 [22:37:00 -0300], Eduardo Habkost wrote: > On Mon, Jun 16, 2014 at 05:25:00PM -0700, Nishanth Aravamudan wrote: > > On 16.06.2014 [17:51:50 -0300], Eduardo Habkost wrote: > > > On Mon, Jun 16, 2014 at 06:16:29PM +1000, Alexey Kardashevskiy wrote: > > > > On 06/16/2014 05:53 PM, Alexey Kardashevskiy wrote: > > > > > c4177479 "spapr: make sure RMA is in first mode of first memory node" > > > > > introduced regression which prevents from running guests with memoryless > > > > > NUMA node#0 which may happen on real POWER8 boxes and which would make > > > > > sense to debug in QEMU. > > > > > > > > > > This patchset aim is to fix that and also fix various code problems in > > > > > memory nodes generation. > > > > > > > > > > These 2 patches could be merged (the resulting patch looks rather ugly): > > > > > spapr: Use DT memory node rendering helper for other nodes > > > > > spapr: Move DT memory node rendering to a helper > > > > > > > > > > Please comment. Thanks! > > > > > > > > > > > > > Sure I forgot to add an example of what I am trying to run without errors > > > > and warnings: > > > > > > > > /home/aik/qemu-system-ppc64 \ > > > > -enable-kvm \ > > > > -machine pseries \ > > > > -nographic \ > > > > -vga none \ > > > > -drive id=id0,if=none,file=virtimg/fc20_24GB.qcow2,format=qcow2 \ > > > > -device scsi-disk,id=id1,drive=id0 \ > > > > -m 2080 \ > > > > -smp 8 \ > > > > -numa node,nodeid=0,cpus=0-7,memory=0 \ > > > > -numa node,nodeid=2,cpus=0-3,mem=1040 \ > > > > -numa node,nodeid=4,cpus=4-7,mem=1040 > > > > > > (Note: I will ignore the "cpus" argument for the discussion below.) > > > > > > I understand now that the non-contiguous node IDs are guest-visible. > > > > > > But I still would like to understand the motivations for your use case, > > > to understand which solution makes more sense. > > > > > > If you really want 5 nodes, you just need to write this: > > > -numa node,nodeid=0,cpus=0-7,memory=0 \ > > > -numa node,nodeid=1 \ > > > -numa node,nodeid=2,cpus=0-3,mem=1040 \ > > > -numa node,nodeid=3 \ > > > -numa node,nodeid=4,cpus=4-7,mem=1040 > > > > > > If you just want 3 nodes, you can just write this: > > > -numa node,nodeid=0,cpus=0-7,memory=0 \ > > > -numa node,nodeid=1,cpus=0-3,mem=1040 \ > > > -numa node,nodeid=4,cpus=4-7,mem=1040 > > > > No, this doesn't do what you think it would :) > > That was a typo. I meant: > -numa node,nodeid=0,cpus=0-7,memory=0 \ > -numa node,nodeid=1,cpus=0-3,mem=1040 \ > -numa node,nodeid=2,cpus=4-7,mem=1040 Ok, that's fair, but I think we all agree now that the goal is two-fold: 1) properly support memoryless nodes (including node 0) in ppc 2) properly support sparse NUMA numbering Thanks, Nish