From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451Ab1HQGkW (ORCPT ); Wed, 17 Aug 2011 02:40:22 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:38516 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750721Ab1HQGkU convert rfc822-to-8bit (ORCPT ); Wed, 17 Aug 2011 02:40:20 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 17 Aug 2011 02:40:19 -0400 Message-ID: Subject: Re: [PATCH 2/5] writeback: dirty position control From: David Horner To: linux-kernel@vger.kernel.org, fengguang.wu@intel.com Cc: jack@suse.cz Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I noticed a significant typo below (another of those thousand eyes, thanks to Jan Kara's post that started ne looking) : > +static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, > + unsigned long thresh, ... > + * For JBOD case, bdi_thresh (not bdi_dirty!) could fluctuate up to its > + * own size, so move the slope over accordingly. > + */ > + if (unlikely(bdi_thresh > thresh)) > + bdi_thresh = thresh; > + /* > + * scale global setpoint to bdi's:  setpoint *= bdi_thresh / thresh > + */ > + x = div_u64((u64)bdi_thresh << 16, thresh | 1);                   ^ I believe should be    x = div_u64((u64)bdi_thresh << 16, thresh + 1);   David Horner