Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933426AbaGURwz (ORCPT ); Mon, 21 Jul 2014 13:52:55 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:34772 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932647AbaGURwx (ORCPT ); Mon, 21 Jul 2014 13:52:53 -0400 Date: Mon, 21 Jul 2014 10:52:41 -0700 From: Nishanth Aravamudan To: Jiang Liu Cc: Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , Grant Likely , Rob Herring , Tony Luck , linux-mm@kvack.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [RFC Patch V1 22/30] mm, of: Use cpu_to_mem()/numa_mem_id() to support memoryless node Message-ID: <20140721175241.GF4156@linux.vnet.ibm.com> References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> <1405064267-11678-23-git-send-email-jiang.liu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1405064267-11678-23-git-send-email-jiang.liu@linux.intel.com> X-Operating-System: Linux 3.13.0-32-generic (x86_64) User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14072117-0928-0000-0000-00000386E522 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11.07.2014 [15:37:39 +0800], Jiang Liu wrote: > When CONFIG_HAVE_MEMORYLESS_NODES is enabled, cpu_to_node()/numa_node_id() > may return a node without memory, and later cause system failure/panic > when calling kmalloc_node() and friends with returned node id. > So use cpu_to_mem()/numa_mem_id() instead to get the nearest node with > memory for the/current cpu. > > If CONFIG_HAVE_MEMORYLESS_NODES is disabled, cpu_to_mem()/numa_mem_id() > is the same as cpu_to_node()/numa_node_id(). > > Signed-off-by: Jiang Liu > --- > drivers/of/base.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index b9864806e9b8..40d4772973ad 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -85,7 +85,7 @@ EXPORT_SYMBOL(of_n_size_cells); > #ifdef CONFIG_NUMA > int __weak of_node_to_nid(struct device_node *np) > { > - return numa_node_id(); > + return numa_mem_id(); > } > #endif Um, NAK. of_node_to_nid() returns the NUMA node ID for a given device tree node. The default should be the physically local NUMA node, not the nearest memory-containing node. I think the general direction of this patchset is good -- what NUMA information do we actually are about at each callsite. But the execution is blind and doesn't consider at all what the code is actually doing. The changelogs are all identical and don't actually provide any information about what errors this (or any) specific patch are resolving. Thanks, Nish -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/