From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756316AbcFHITK (ORCPT ); Wed, 8 Jun 2016 04:19:10 -0400 Received: from LGEAMRELO13.lge.com ([156.147.23.53]:55777 "EHLO lgeamrelo13.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756279AbcFHITG (ORCPT ); Wed, 8 Jun 2016 04:19:06 -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: Wed, 8 Jun 2016 17:19:03 +0900 From: Minchan Kim To: Johannes Weiner CC: , , Andrew Morton , Rik van Riel , Mel Gorman , Andrea Arcangeli , Andi Kleen , Michal Hocko , Tim Chen , Subject: Re: [PATCH 09/10] mm: only count actual rotations as LRU reclaim cost Message-ID: <20160608081903.GE28620@bbox> References: <20160606194836.3624-1-hannes@cmpxchg.org> <20160606194836.3624-10-hannes@cmpxchg.org> MIME-Version: 1.0 In-Reply-To: <20160606194836.3624-10-hannes@cmpxchg.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB06/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/06/08 17:17:57, Serialize by Router on LGEKRMHUB06/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/06/08 17:17:57, Serialize complete at 2016/06/08 17:17:57 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 Mon, Jun 06, 2016 at 03:48:35PM -0400, Johannes Weiner wrote: > Noting a reference on an active file page but still deactivating it > represents a smaller cost of reclaim than noting a referenced > anonymous page and actually physically rotating it back to the head. > The file page *might* refault later on, but it's definite progress > toward freeing pages, whereas rotating the anonymous page costs us > real time without making progress toward the reclaim goal. > > Don't treat both events as equal. The following patch will hook up LRU > balancing to cache and swap refaults, which are a much more concrete > cost signal for reclaiming one list over the other. Remove the > maybe-IO cost bias from page references, and only note the CPU cost > for actual rotations that prevent the pages from getting reclaimed. > > Signed-off-by: Johannes Weiner Acked-by: Minchan Kim