From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760005AbcDEUhT (ORCPT ); Tue, 5 Apr 2016 16:37:19 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49959 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752080AbcDEUhS (ORCPT ); Tue, 5 Apr 2016 16:37:18 -0400 Date: Tue, 5 Apr 2016 13:37:16 -0700 From: Andrew Morton To: Minchan Kim Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Johannes Weiner , stable@vger.kernel.org Subject: Re: [PATCH] mm: vmscan: reclaim highmem zone if buffer_heads is over limit Message-Id: <20160405133716.00e0f6ce92dc4bfed50c5334@linux-foundation.org> In-Reply-To: <1459727169-5698-1-git-send-email-minchan@kernel.org> References: <1459727169-5698-1-git-send-email-minchan@kernel.org> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 4 Apr 2016 08:46:09 +0900 Minchan Kim wrote: > We have been reclaimed highmem zone if buffer_heads is over limit > but [1] changed the behavior so it doesn't reclaim highmem zone > although buffer_heads is over the limit. > This patch restores the logic. > > [1] commit 6b4f7799c6a5 ("mm: vmscan: invoke slab shrinkers from shrink_zone()") > > ... > > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2550,7 +2550,7 @@ 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) { > + gfp_zone(sc->gfp_mask), sc->nodemask) { > enum zone_type classzone_idx; > > if (!populated_zone(zone)) Wait wut wot. We broke this over a year ago? Highmem pagecache pages pinning buffer_head lowmem used to be a huuuge problem. Before most of you were born ;)