From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e2.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m8UFof4f019801 for ; Tue, 30 Sep 2008 11:50:41 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m8UFoeDk134450 for ; Tue, 30 Sep 2008 11:50:41 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m8UFoeMS004787 for ; Tue, 30 Sep 2008 11:50:40 -0400 Subject: Re: [PATCH] mm: show node to memory section relationship with symlinks in sysfs From: Dave Hansen In-Reply-To: <20080930163324.44A7.E1E9C6FF@jp.fujitsu.com> References: <20080929200509.GC21255@us.ibm.com> <20080930163324.44A7.E1E9C6FF@jp.fujitsu.com> Content-Type: text/plain Date: Tue, 30 Sep 2008 08:50:37 -0700 Message-Id: <1222789837.17630.41.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Yasunori Goto Cc: Gary Hade , linux-mm@kvack.org, Andrew Morton , Badari Pulavarty , Mel Gorman , Chris McDermott , linux-kernel@vger.kernel.org, Ingo Molnar , Greg KH , Nish Aravamudan List-ID: On Tue, 2008-09-30 at 17:06 +0900, Yasunori Goto wrote: > > +#define section_nr_to_nid(section_nr) pfn_to_nid(section_nr_to_pfn(section_nr)) > > #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ > > If the first page of the section is not valid, then this section_nr_to_nid() > doesn't return correct value. > > I tested this patch. In my box, the start_pfn of node 1 is 1200400, but > section_nr_to_pfn(mem_blk->phys_index) returns 1200000. As a result, > the section is linked to node 0. Crap, I was worried about that. Gary, this means that we have a N:1 relationship between NUMA nodes and sections. This normally isn't a problem because sections don't really care about nodes and they layer underneath them. We'll probably need multiple symlinks in each section directory. -- Dave -- 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