From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f178.google.com (mail-ie0-f178.google.com [209.85.223.178]) by kanga.kvack.org (Postfix) with ESMTP id 32BF72802C8 for ; Mon, 6 Jul 2015 18:05:11 -0400 (EDT) Received: by iebmu5 with SMTP id mu5so122439868ieb.1 for ; Mon, 06 Jul 2015 15:05:11 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id z5si14537084igg.2.2015.07.06.15.05.10 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Jul 2015 15:05:10 -0700 (PDT) Date: Mon, 6 Jul 2015 15:05:09 -0700 From: Andrew Morton Subject: Re: mm/page_alloc.c:247:6: warning: unused variable 'nid' Message-Id: <20150706150509.48abfb09376605d611ceadbe@linux-foundation.org> In-Reply-To: <20150704181008.GA1374@node.dhcp.inet.fi> References: <201507041743.GoTZWMrj%fengguang.wu@intel.com> <20150704181008.GA1374@node.dhcp.inet.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: kbuild test robot , Mel Gorman , kbuild-all@01.org, Linux Memory Management List On Sat, 4 Jul 2015 21:10:08 +0300 "Kirill A. Shutemov" wrote: > On Sat, Jul 04, 2015 at 05:26:47PM +0800, kbuild test robot wrote: > > tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > head: 14a6f1989dae9445d4532941bdd6bbad84f4c8da > > commit: 3b242c66ccbd60cf47ab0e8992119d9617548c23 x86: mm: enable deferred struct page initialisation on x86-64 > > date: 3 days ago > > config: x86_64-randconfig-x006-201527 (attached as .config) > > reproduce: > > git checkout 3b242c66ccbd60cf47ab0e8992119d9617548c23 > > # save the attached .config to linux build tree > > make ARCH=x86_64 > > > > All warnings (new ones prefixed by >>): > > > > mm/page_alloc.c: In function 'early_page_uninitialised': > > >> mm/page_alloc.c:247:6: warning: unused variable 'nid' [-Wunused-variable] > > int nid = early_pfn_to_nid(pfn); > > We can silence the warning with something like patch below. But I'm not > sure it worth it. > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 754c25966a0a..746a6a7b0535 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -911,7 +911,7 @@ extern char numa_zonelist_order[]; > #ifndef CONFIG_NEED_MULTIPLE_NODES > > extern struct pglist_data contig_page_data; > -#define NODE_DATA(nid) (&contig_page_data) > +#define NODE_DATA(nid) ((void)nid, &contig_page_data) > #define NODE_MEM_MAP(nid) mem_map > > #else /* CONFIG_NEED_MULTIPLE_NODES */ Sigh. Macros do suck. If NODE_DATA was a regular old C function this warning wouldn't occur. Problem is, we should then rename it to "node_data" and that would require 246 edits. I suppose we could compromise and do static inline struct pglist_data *NODE_DATA(int nid) ? -- 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