From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754644AbcBWS5f (ORCPT ); Tue, 23 Feb 2016 13:57:35 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:59904 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753250AbcBWS5e (ORCPT ); Tue, 23 Feb 2016 13:57:34 -0500 Date: Tue, 23 Feb 2016 10:57:22 -0800 From: Johannes Weiner To: Mel Gorman Cc: Linux-MM , Rik van Riel , Vlastimil Babka , LKML Subject: Re: [PATCH 06/27] mm, vmscan: Begin reclaiming pages on a per-node basis Message-ID: <20160223185722.GF13816@cmpxchg.org> References: <1456239890-20737-1-git-send-email-mgorman@techsingularity.net> <1456239890-20737-7-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456239890-20737-7-git-send-email-mgorman@techsingularity.net> 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 Tue, Feb 23, 2016 at 03:04:29PM +0000, Mel Gorman wrote: > @@ -2428,10 +2448,11 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc, > reclaimed = sc->nr_reclaimed; > scanned = sc->nr_scanned; > > + sc->reclaim_idx = reclaim_idx; > shrink_zone_memcg(zone, memcg, sc, &lru_pages); > zone_lru_pages += lru_pages; The setting of sc->reclaim_idx is unexpected here. Why not set it in the caller and eliminate the reclaim_idx parameter? > @@ -2558,16 +2579,12 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) > sc->gfp_mask |= __GFP_HIGHMEM; > > for_each_zone_zonelist_nodemask(zone, z, zonelist, > - requested_highidx, sc->nodemask) { It's unfortunate that we start with the lowest zone here. For Normal allocations, the most common allocations, this will always have two full shrink_node() rounds that skip over everything >DMA in the first, then over everything >DMA32 in the second, even though all pages on the node are valid reclaim candidates for that allocation.