From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 616946B0099 for ; Fri, 19 Feb 2010 10:02:27 -0500 (EST) Date: Fri, 19 Feb 2010 09:01:44 -0600 (CST) From: Christoph Lameter Subject: Re: [PATCH 03/12] mm: Share the anon_vma ref counts between KSM and page migration In-Reply-To: <20100219140500.GG30258@csn.ul.ie> Message-ID: References: <1266516162-14154-1-git-send-email-mel@csn.ul.ie> <1266516162-14154-4-git-send-email-mel@csn.ul.ie> <20100219091859.195d922c.kamezawa.hiroyu@jp.fujitsu.com> <20100219140500.GG30258@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: KAMEZAWA Hiroyuki , Andrea Arcangeli , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "hugh.dickins@tiscali.co.uk" List-ID: On Fri, 19 Feb 2010, Mel Gorman wrote: > > Nitpick: > > I think this refcnt has something different characteristics than other > > usual refcnts. Even when refcnt goes down to 0, anon_vma will not be freed. > > So, I think some kind of name as temporal_reference_count is better than > > simple "refcnt". Then, it will be clearer what this refcnt is for. > > > > When I read this in a few years, I'll have no idea what "temporal" is > referring to. The holder of this account is by a process that does not > necessarily own the page or its mappings but "remote" has special > meaning as well. "external_count" ? We could think about getting rid of RCU for anon_vmas and use the refcount for everything. Would make the handling consistent with other users but will have performance implications. Hugh what do you say about this? -- 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