From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 7906E6B0089 for ; Tue, 16 Feb 2010 03:41:43 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o1G8ffr2020924 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 16 Feb 2010 17:41:41 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id E2D0345DE51 for ; Tue, 16 Feb 2010 17:41:40 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id BBED545DE4E for ; Tue, 16 Feb 2010 17:41:40 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6A0F31DB803C for ; Tue, 16 Feb 2010 17:41:40 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 080051DB8038 for ; Tue, 16 Feb 2010 17:41:40 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 03/12] Export unusable free space index via /proc/pagetypeinfo In-Reply-To: <20100216083612.GA26086@csn.ul.ie> References: <20100216152106.72FA.A69D9226@jp.fujitsu.com> <20100216083612.GA26086@csn.ul.ie> Message-Id: <20100216173832.730F.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 16 Feb 2010 17:41:39 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > On Tue, Feb 16, 2010 at 04:03:29PM +0900, KOSAKI Motohiro wrote: > > > Unusuable free space index is a measure of external fragmentation that > > > takes the allocation size into account. For the most part, the huge page > > > size will be the size of interest but not necessarily so it is exported > > > on a per-order and per-zone basis via /proc/pagetypeinfo. > > > > Hmmm.. > > /proc/pagetype have a machine unfriendly format. perhaps, some user have own ugly > > /proc/pagetype parser. It have a little risk to break userland ABI. > > > > It's very low risk. I doubt there are machine parsers of > /proc/pagetypeinfo because there are very few machine-orientated actions > that can be taken based on the information. It's more informational for > a user if they were investigating fragmentation problems. > > > I have dumb question. Why can't we use another file? > > I could. What do you suggest? I agree it's low risk. but personally I hope fragmentation ABI keep very stable because I expect some person makes userland compaction daemon. (read fragmentation index from /proc and write /proc/compact_memory if necessary). then, if possible, I hope fragmentation info have individual /proc file. -- 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