From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751830AbcGRQUl (ORCPT ); Mon, 18 Jul 2016 12:20:41 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:53294 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455AbcGRQUj (ORCPT ); Mon, 18 Jul 2016 12:20:39 -0400 Date: Mon, 18 Jul 2016 12:20:31 -0400 From: Johannes Weiner To: Mel Gorman Cc: Andrew Morton , Minchan Kim , Vlastimil Babka , Linux-MM , LKML Subject: Re: [PATCH 3/5] mm, pagevec: Release/reacquire lru_lock on pgdat change Message-ID: <20160718162031.GF16465@cmpxchg.org> References: <1468588165-12461-1-git-send-email-mgorman@techsingularity.net> <1468588165-12461-4-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1468588165-12461-4-git-send-email-mgorman@techsingularity.net> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 15, 2016 at 02:09:23PM +0100, Mel Gorman wrote: > With node-lru, the locking is based on the pgdat. Previously it was > required that a pagevec drain released one zone lru_lock and acquired > another zone lru_lock on every zone change. Now, it's only necessary if > the node changes. The end-result is fewer lock release/acquires if the > pages are all on the same node but in different zones. > > Signed-off-by: Mel Gorman This could make quite a difference on some workloads, from a whole series perspective, when considering that we had the round robin fair zone allocator on top of this. Page batches that span multiple nodes on the other hand are much less likely. Acked-by: Johannes Weiner