From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id 3836A6B0307 for ; Mon, 25 Jun 2012 00:26:50 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 30FFF3EE0BC for ; Mon, 25 Jun 2012 13:26:48 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 01B4E45DE55 for ; Mon, 25 Jun 2012 13:26:48 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id CCE7945DE50 for ; Mon, 25 Jun 2012 13:26:47 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id BE641E18007 for ; Mon, 25 Jun 2012 13:26:47 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 76CB21DB803E for ; Mon, 25 Jun 2012 13:26:47 +0900 (JST) Message-ID: <4FE7E7FA.80702@jp.fujitsu.com> Date: Mon, 25 Jun 2012 13:24:26 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH 1/6] memcg: replace unsigned long by u64 to avoid overflow References: <1340432134-5178-1-git-send-email-liwp.linux@gmail.com> <20120623081514.GJ27816@cmpxchg.org> <20120623090339.GA6184@kernel> <20120623092654.GL27816@cmpxchg.org> In-Reply-To: <20120623092654.GL27816@cmpxchg.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Wanpeng Li , linux-mm@kvack.org, Michal Hocko , Balbir Singh , Andrew Morton , Mel Gorman , Minchan Kim , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Gavin Shan (2012/06/23 18:26), Johannes Weiner wrote: > On Sat, Jun 23, 2012 at 05:03:39PM +0800, Wanpeng Li wrote: >> On Sat, Jun 23, 2012 at 10:15:14AM +0200, Johannes Weiner wrote: >>> On Sat, Jun 23, 2012 at 02:15:34PM +0800, Wanpeng Li wrote: >>>> From: Wanpeng Li >>>> >>>> Since the return value variable in mem_cgroup_zone_nr_lru_pages and >>>> mem_cgroup_node_nr_lru_pages functions are u64, so replace the return >>>> value of funtions by u64 to avoid overflow. >>> >>> I wonder what 16 TB of memory must think running on a 32-bit kernel... >>> "What is this, an address space for ants?" >> >> Hi Johannes, >> >> You mean change all u64 in memcg to unsigned long? or something I >> miss.... > > Not _all_ of them, we have some that count bytes. But those counting > pages should probably be ulong, yes. > > I think Kame added the ones that you wanted to adjust the surroundings > for in particular, so let's ask him. Kame? > I've been using 'unsigned long' for the number of pages and 'u64' for the number of bytes. I think it's enough and it should be. I don't have any reason to use u64 for the number of pages on 32bit archs. If 'bytes' are handled by 'unsigned long', please fix it. BTW, zone_page_state()::/include/linux/vmstat.h returns 'unsigned long'. If you want to change this in memcg, please change zone's ones first. Thanks, -Kame -- 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/ . Don't email: email@kvack.org