From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f173.google.com (mail-lb0-f173.google.com [209.85.217.173]) by kanga.kvack.org (Postfix) with ESMTP id 1B7076B0038 for ; Mon, 13 Apr 2015 09:38:53 -0400 (EDT) Received: by lbbzk7 with SMTP id zk7so58853828lbb.0 for ; Mon, 13 Apr 2015 06:38:52 -0700 (PDT) Received: from forward-corp1g.mail.yandex.net (forward-corp1g.mail.yandex.net. [2a02:6b8:0:1402::10]) by mx.google.com with ESMTPS id j5si8429082laf.127.2015.04.13.06.38.50 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Apr 2015 06:38:51 -0700 (PDT) Message-ID: <552BC6E8.1040400@yandex-team.ru> Date: Mon, 13 Apr 2015 16:38:48 +0300 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH] of: return NUMA_NO_NODE from fallback of_node_to_nid() References: <20150408165920.25007.6869.stgit@buzz> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Rob Herring Cc: Grant Likely , "devicetree@vger.kernel.org" , Rob Herring , "linux-kernel@vger.kernel.org" , sparclinux@vger.kernel.org, "linux-mm@kvack.org" , linuxppc-dev On 13.04.2015 16:22, Rob Herring wrote: > On Wed, Apr 8, 2015 at 11:59 AM, Konstantin Khlebnikov > wrote: >> Node 0 might be offline as well as any other numa node, >> in this case kernel cannot handle memory allocation and crashes. >> >> Signed-off-by: Konstantin Khlebnikov >> Fixes: 0c3f061c195c ("of: implement of_node_to_nid as a weak function") >> --- >> drivers/of/base.c | 2 +- >> include/linux/of.h | 5 ++++- >> 2 files changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/of/base.c b/drivers/of/base.c >> index 8f165b112e03..51f4bd16e613 100644 >> --- a/drivers/of/base.c >> +++ b/drivers/of/base.c >> @@ -89,7 +89,7 @@ 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_NO_NODE; > > This is going to break any NUMA machine that enables OF and expects > the weak function to work. Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used. > > Rob > >> } >> #endif >> >> diff --git a/include/linux/of.h b/include/linux/of.h >> index dfde07e77a63..78a04ee85a9c 100644 >> --- a/include/linux/of.h >> +++ b/include/linux/of.h >> @@ -623,7 +623,10 @@ static inline const char *of_prop_next_string(struct property *prop, >> #if defined(CONFIG_OF) && defined(CONFIG_NUMA) >> extern int of_node_to_nid(struct device_node *np); >> #else >> -static inline int of_node_to_nid(struct device_node *device) { return 0; } >> +static inline int of_node_to_nid(struct device_node *device) >> +{ >> + return NUMA_NO_NODE; >> +} >> #endif >> >> static inline struct device_node *of_find_matching_node( >> >> -- >> To unsubscribe from this list: send the line "unsubscribe devicetree" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- Konstantin -- 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