From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 264758D0039 for ; Sun, 27 Feb 2011 11:07:33 -0500 (EST) Received: by pxi9 with SMTP id 9so747305pxi.14 for ; Sun, 27 Feb 2011 08:07:31 -0800 (PST) Date: Mon, 28 Feb 2011 01:07:21 +0900 From: Minchan Kim Subject: Re: [PATCH v5 3/9] writeback: convert variables to unsigned Message-ID: <20110227160721.GB3226@barrios-desktop> References: <1298669760-26344-1-git-send-email-gthelen@google.com> <1298669760-26344-4-git-send-email-gthelen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1298669760-26344-4-git-send-email-gthelen@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Greg Thelen Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, containers@lists.osdl.org, Andrea Righi , Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura , Ciju Rajan K , David Rientjes , Wu Fengguang , Chad Talbott , Justin TerAvest , Vivek Goyal On Fri, Feb 25, 2011 at 01:35:54PM -0800, Greg Thelen wrote: > Convert two balance_dirty_pages() page counter variables (nr_reclaimable > and nr_writeback) from 'long' to 'unsigned long'. > > These two variables are used to store results from global_page_state(). > global_page_state() returns unsigned long and carefully sums per-cpu > counters explicitly avoiding returning a negative value. > > Signed-off-by: Greg Thelen Reviewed-by: Minchan Kim > --- > Changelog since v4: > - Created this patch for clarity. Previously this patch was integrated within > the "writeback: create dirty_info structure" patch. > > mm/page-writeback.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index 2cb01f6..4408e54 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -478,8 +478,10 @@ unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long dirty) > static void balance_dirty_pages(struct address_space *mapping, > unsigned long write_chunk) > { > - long nr_reclaimable, bdi_nr_reclaimable; > - long nr_writeback, bdi_nr_writeback; > + unsigned long nr_reclaimable; > + long bdi_nr_reclaimable; > + unsigned long nr_writeback; > + long bdi_nr_writeback; > unsigned long background_thresh; > unsigned long dirty_thresh; > unsigned long bdi_thresh; > -- > 1.7.3.1 > bdi_nr_[reclaimable|writeback] can return negative value? When I just look through bdi_stat_sum, it uses *percpu_counter_sum_positive*. So I guess it always returns positive value. If it is right, could you change it, too? -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org