From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752777Ab0H0KkE (ORCPT ); Fri, 27 Aug 2010 06:40:04 -0400 Received: from casper.infradead.org ([85.118.1.10]:33111 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751291Ab0H0KkC convert rfc822-to-8bit (ORCPT ); Fri, 27 Aug 2010 06:40:02 -0400 Subject: Re: [PATCH] writeback: remove the internal 5% low bound on dirty_ratio From: Peter Zijlstra To: Wu Fengguang Cc: Andrew Morton , KOSAKI Motohiro , Neil Brown , Con Kolivas , Jan Kara , Rik van Riel , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "david@fromorbit.com" , "hch@lst.de" , "axboe@kernel.dk" In-Reply-To: <20100827103603.GB6237@localhost> References: <20100827103603.GB6237@localhost> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 27 Aug 2010 12:39:39 +0200 Message-ID: <1282905579.1975.2141.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-08-27 at 18:36 +0800, Wu Fengguang wrote: > The dirty_ratio was siliently limited in global_dirty_limits() to >= 5%. > This is not a user expected behavior. And it's inconsistent with > calc_period_shift(), which uses the plain vm_dirty_ratio value. > > Let's rip the internal bound. > > At the same time, fix balance_dirty_pages() to work with the > dirty_thresh=0 case. This allows applications to proceed when > dirty+writeback pages are all cleaned. > > And ">" fits with the name "exceeded" better than ">=" does. Neil > think it is an aesthetic improvement as well as a functional one :) > > CC: Jan Kara > CC: Rik van Riel Acked-by: Peter Zijlstra > Proposed-by: Con Kolivas > Reviewed-by: Neil Brown > Reviewed-by: KOSAKI Motohiro > Signed-off-by: Wu Fengguang