From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751649AbdBXBu0 (ORCPT ); Thu, 23 Feb 2017 20:50:26 -0500 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:41687 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751283AbdBXBuY (ORCPT ); Thu, 23 Feb 2017 20:50:24 -0500 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Fri, 24 Feb 2017 10:49:39 +0900 From: Minchan Kim To: Shaohua Li Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kernel-team@fb.com, mhocko@suse.com, hughd@google.com, hannes@cmpxchg.org, riel@redhat.com, mgorman@techsingularity.net, akpm@linux-foundation.org Subject: Re: [PATCH V4 3/6] mm: move MADV_FREE pages into LRU_INACTIVE_FILE list Message-ID: <20170224014939.GC9818@bbox> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 22, 2017 at 10:50:41AM -0800, Shaohua Li wrote: > madv MADV_FREE indicate pages are 'lazyfree'. They are still anonymous > pages, but they can be freed without pageout. To destinguish them > against normal anonymous pages, we clear their SwapBacked flag. > > MADV_FREE pages could be freed without pageout, so they pretty much like > used once file pages. For such pages, we'd like to reclaim them once > there is memory pressure. Also it might be unfair reclaiming MADV_FREE > pages always before used once file pages and we definitively want to > reclaim the pages before other anonymous and file pages. > > To speed up MADV_FREE pages reclaim, we put the pages into > LRU_INACTIVE_FILE list. The rationale is LRU_INACTIVE_FILE list is tiny > nowadays and should be full of used once file pages. Reclaiming > MADV_FREE pages will not have much interfere of anonymous and active > file pages. And the inactive file pages and MADV_FREE pages will be > reclaimed according to their age, so we don't reclaim too many MADV_FREE > pages too. Putting the MADV_FREE pages into LRU_INACTIVE_FILE_LIST also > means we can reclaim the pages without swap support. This idea is > suggested by Johannes. > > This patch doesn't move MADV_FREE pages to LRU_INACTIVE_FILE list yet to > avoid bisect failure, next patch will do it. > > The patch is based on Minchan's original patch. > > Cc: Michal Hocko > Cc: Minchan Kim > Cc: Hugh Dickins > Cc: Rik van Riel > Cc: Mel Gorman > Cc: Andrew Morton > Suggested-by: Johannes Weiner > Signed-off-by: Shaohua Li Other than that Johannes pointed out, code itself looks good to me. However, I hope to merge this patch with next one. It's enough simple to merge, change behavior(about deactivation), mark_page_lazyfree is introduced but there is no callsite to use it in this patch. I don't think it's worth to separate.