From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753540Ab2LMKlJ (ORCPT ); Thu, 13 Dec 2012 05:41:09 -0500 Received: from cantor2.suse.de ([195.135.220.15]:48919 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752800Ab2LMKlI (ORCPT ); Thu, 13 Dec 2012 05:41:08 -0500 Date: Thu, 13 Dec 2012 10:41:04 +0000 From: Mel Gorman To: Johannes Weiner Cc: Andrew Morton , Rik van Riel , Michal Hocko , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 3/8] mm: vmscan: save work scanning (almost) empty LRU lists Message-ID: <20121213104104.GX1009@suse.de> References: <1355348620-9382-1-git-send-email-hannes@cmpxchg.org> <1355348620-9382-4-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1355348620-9382-4-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 12, 2012 at 04:43:35PM -0500, Johannes Weiner wrote: > In certain cases (kswapd reclaim, memcg target reclaim), a fixed > minimum amount of pages is scanned from the LRU lists on each > iteration, to make progress. > > Do not make this minimum bigger than the respective LRU list size, > however, and save some busy work trying to isolate and reclaim pages > that are not there. > > Signed-off-by: Johannes Weiner This looks like a corner case where the LRU size would have to be smaller than SWAP_CLUSTER_MAX. Is that common enough to care? It looks correct, I'm just curious. Acked-by: Mel Gorman -- Mel Gorman SUSE Labs