From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46217) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1ti5-0005qx-Kt for qemu-devel@nongnu.org; Mon, 08 Jun 2015 05:51:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z1ti0-0001Gw-88 for qemu-devel@nongnu.org; Mon, 08 Jun 2015 05:51:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40960) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1ti0-0001G5-1f for qemu-devel@nongnu.org; Mon, 08 Jun 2015 05:51:08 -0400 Date: Mon, 8 Jun 2015 11:51:03 +0200 From: Igor Mammedov Message-ID: <20150608115103.3f888b1e@nial.brq.redhat.com> In-Reply-To: <20150608055818.GE25832@in.ibm.com> References: <1430982264-25497-1-git-send-email-bharata@linux.vnet.ibm.com> <20150513180607.GK25766@thinpad.lan.raisama.net> <55546D3A.8010509@redhat.com> <20150525074757.GE32383@in.ibm.com> <20150525174240.GP17796@thinpad.lan.raisama.net> <20150608055818.GE25832@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v0] numa: API to lookup NUMA node by address List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bharata B Rao Cc: qemu-devel@nongnu.org, Paolo Bonzini , Eduardo Habkost , david@gibson.dropbear.id.au On Mon, 8 Jun 2015 11:28:18 +0530 Bharata B Rao wrote: > On Mon, May 25, 2015 at 02:42:40PM -0300, Eduardo Habkost wrote: > > On Mon, May 25, 2015 at 01:17:57PM +0530, Bharata B Rao wrote: > > > On Thu, May 14, 2015 at 11:39:06AM +0200, Paolo Bonzini wrote: > > > > On 13/05/2015 20:06, Eduardo Habkost wrote: > > > > > Also, this introduces a circular dependency between pc-dimm.c and > > > > > numa.c. Instead of that, pc-dimm could simply notify us when a new > > > > > device is realized (with just (addr, end, node) as arguments), so we can > > > > > save the list of memory ranges inside struct node_info. > > > > > > > > > > I wonder if the memory API already provides something that would help > > > > > us. Paolo, do you see a way we could simply use a MemoryRegion as input > > > > > to lookup the NUMA node? > > > > > > > > No, but I guess you could add a numa_get/set_memory_region_node_id API > > > > that uses a hash table. That's a variant of the "pc-dimm could simply > > > > notify" numa.c that you propose above. > > > > > > While you say we can't use MemoryRegion as input to lookup the NUMA node, > > > you suggest that we add numa_get/set_memory_region_node_id. Does this API > > > get/set NUMA node id for the given MemoryRegion ? > > > > I was going to suggest that, but it would require changing the > > non-memdev code path to create a MemoryRegion for each node, too. So > > having a numa_set_mem_node_id(start_addr, end_addr, node_id) API would > > be simpler. > > In order to save the list of memory ranges inside node_info, I tried this > approach where I call > > numa_set_mem_node_id(dimm.addr, dimm.size, dimm.node) from > > pc_dimm_realize(), but > > the value of dimm.addr is finalized only later in ->plug(). > > So we would have to call this API from arch code like pc_dimm_plug(). > Is that acceptable ? Could you query pc_dimms' numa property each time you need mapping instead of additionally storing that mapping elsewhere? > > Regards, > Bharata. > >