From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753540AbdAZJ7K (ORCPT ); Thu, 26 Jan 2017 04:59:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:44075 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753332AbdAZJ7J (ORCPT ); Thu, 26 Jan 2017 04:59:09 -0500 Date: Thu, 26 Jan 2017 09:57:45 +0000 From: Mel Gorman To: Johannes Weiner Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 2/5] mm: vmscan: kick flushers when we encounter dirty pages on the LRU Message-ID: <20170126095745.ueigbrsop5vgmwzj@suse.de> References: <20170123181641.23938-1-hannes@cmpxchg.org> <20170123181641.23938-3-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20170123181641.23938-3-hannes@cmpxchg.org> 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 Mon, Jan 23, 2017 at 01:16:38PM -0500, Johannes Weiner wrote: > Memory pressure can put dirty pages at the end of the LRU without > anybody running into dirty limits. Don't start writing individual > pages from kswapd while the flushers might be asleep. > > Signed-off-by: Johannes Weiner I don't understand the motivation for checking the wb_reason name. Maybe it was easier to eyeball while reading ftraces. The comment about the flusher not doing its job could also be as simple as the writes took place and clean pages were reclaimed before dirty_expire was reached. Not impossible if there was a light writer combined with a heavy reader or a large number of anonymous faults. Anyway; Acked-by: Mel Gorman -- Mel Gorman SUSE Labs