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 e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l5FEnvgt027200 for ; Fri, 15 Jun 2007 10:49:57 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l5FFqmGw344142 for ; Fri, 15 Jun 2007 11:52:48 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l5FFqmOJ004922 for ; Fri, 15 Jun 2007 11:52:48 -0400 Subject: Re: [RFC] memory unplug v5 [5/6] page unplug From: Dave Hansen In-Reply-To: <20070614160458.62e20cbd.kamezawa.hiroyu@jp.fujitsu.com> References: <20070614155630.04f8170c.kamezawa.hiroyu@jp.fujitsu.com> <20070614160458.62e20cbd.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain Date: Fri, 15 Jun 2007 08:52:41 -0700 Message-Id: <1181922762.28189.30.camel@spirit> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, mel@csn.ul.ie, y-goto@jp.fujitsu.com, clameter@sgi.com, hugh@veritas.com List-ID: On Thu, 2007-06-14 at 16:04 +0900, KAMEZAWA Hiroyuki wrote: > > + if (start_pfn & (pageblock_nr_pages - 1)) > + return -EINVAL; > + if (end_pfn & (pageblock_nr_pages - 1)) > + return -EINVAL; After reading these, I'm still not sure I know what a pageblock is supposed to be. :) Did those come from Mel's patches? In any case, I think it might be helpful to wrap up some of those references in functions. I was always looking at the patches trying to find if "pageblock_nr_pages" was a local variable or not. A function would surely tell me. static inline int pfn_is_pageblock_aligned(unsigned long pfn) { return pfn & (pageblock_nr_pages - 1) } and, then you get BUG_ON(!pfn_is_pageblock_aligned(start_pfn)); It's pretty obvious what is going on, there. -- 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