From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752864AbcGMJRq (ORCPT ); Wed, 13 Jul 2016 05:17:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:43309 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751436AbcGMJRk (ORCPT ); Wed, 13 Jul 2016 05:17:40 -0400 Date: Wed, 13 Jul 2016 10:17:11 +0100 From: Mel Gorman To: Minchan Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm: fix calculation accounting dirtyable highmem Message-ID: <20160713091711.GI11400@suse.de> References: <1468376593-26444-1-git-send-email-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1468376593-26444-1-git-send-email-minchan@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 13, 2016 at 11:23:13AM +0900, Minchan Kim wrote: > When I tested vmscale in mmtest in 32bit, I found the benchmark > was slow down 0.5 times. > > base node > 1 global-1 > User 12.98 16.04 > System 147.61 166.42 > Elapsed 26.48 38.08 > > With vmstat, I found IO wait avg is much increased compared to > base. > > The reason was highmem_dirtyable_memory accumulates free pages > and highmem_file_pages from HIGHMEM to MOVABLE zones which was > wrong. With that, dirth_thresh in throtlle_vm_write is always > 0 so that it calls congestion_wait frequently if writeback > starts. > > With this patch, it is much recovered. > > base node fi > 1 global-1 fix > User 12.98 16.04 13.78 > System 147.61 166.42 143.92 > Elapsed 26.48 38.08 29.64 > > Signed-off-by: Minchan Kim Thanks. I'll pick this up and send a follow-on series to Andrew with this included. -- Mel Gorman SUSE Labs