From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751859AbcGNB0n (ORCPT ); Wed, 13 Jul 2016 21:26:43 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:35598 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751528AbcGNB0g (ORCPT ); Wed, 13 Jul 2016 21:26:36 -0400 X-Original-SENDERIP: 156.147.1.121 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 165.244.98.150 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Thu, 14 Jul 2016 10:27:52 +0900 From: Minchan Kim To: Mel Gorman CC: Johannes Weiner , Andrew Morton , Linux-MM , Rik van Riel , Vlastimil Babka , Joonsoo Kim , LKML Subject: Re: [PATCH 18/34] mm: rename NR_ANON_PAGES to NR_ANON_MAPPED Message-ID: <20160714012752.GC23512@bbox> References: <1467970510-21195-1-git-send-email-mgorman@techsingularity.net> <1467970510-21195-19-git-send-email-mgorman@techsingularity.net> <20160712145801.GJ5881@cmpxchg.org> <20160713085516.GI9806@techsingularity.net> <20160713130415.GB9905@cmpxchg.org> <20160713133701.GK9806@techsingularity.net> MIME-Version: 1.0 In-Reply-To: <20160713133701.GK9806@techsingularity.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/14 10:26:33, Serialize by Router on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/14 10:26:33, Serialize complete at 2016/07/14 10:26:33 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 13, 2016 at 02:37:01PM +0100, Mel Gorman wrote: > On Wed, Jul 13, 2016 at 09:04:15AM -0400, Johannes Weiner wrote: > > > Obviously I found the new names clearer but I was thinking a lot at the > > > time about mapped vs unmapped due to looking closely at both reclaim and > > > [f|m]advise functions at the time. I found it mildly irksome to switch > > > between the semantics of file/anon when looking at the vmstat updates. > > > > I can see that. It all depends on whether you consider mapping state > > or page type the more fundamental attribute, and coming from the > > mapping perspective those new names make sense as well. > > > > From a reclaim perspective, I consider the mapped state to be more > important. This is particularly true when the advise calls are taken > into account. For example, madvise unmaps the pages without affecting > memory residency (distinct from RSS) without aging. fadvise ignores mapped > pages so the mapped state is very important for advise hints. Similarly, > the mapped state can affect how the pages are aged as mapped pages affect > slab scan rates and incur TLB flushes on unmap. I guess I've been thinking > about mapped/unmapped a lot recently which pushed me towards distinct naming. > > > However, that leaves the disconnect between the enum name and what we > > print to userspace. I find myself having to associate those quite a > > lot to find all the sites that modify a given /proc/vmstat item, and > > that's a bit of a pain if the names don't match. > > > > I was tempted to rename userspace what is printed to vmstat as well but > worried about breaking tools that parse it. > > > I don't care strongly enough to cause a respin of half the series, and > > it's not your problem that I waited until the last revision went into > > mmots to review and comment. But if you agreed to a revert, would you > > consider tacking on a revert patch at the end of the series? > > > > In this case, I'm going to ask the other people on the cc for a > tie-breaker. If someone else prefers the old names then I'm happy for > your patch to be applied on top with my ack instead of respinning the > whole series. > > Anyone for a tie breaker? I have thought it from reclaim perspective for a long time so I tempted to change the naming like new one but there is no big justification for that. In this chance, I vote new name. Thanks.