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 SMTP id 5A75C6B00C7 for ; Mon, 2 Mar 2009 01:19:50 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n226JlfY025039 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 2 Mar 2009 15:19:48 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9423B45DD80 for ; Mon, 2 Mar 2009 15:19:47 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 716D045DD7E for ; Mon, 2 Mar 2009 15:19:47 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 4BF04E08004 for ; Mon, 2 Mar 2009 15:19:47 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id DEA3BE08003 for ; Mon, 2 Mar 2009 15:19:46 +0900 (JST) Date: Mon, 2 Mar 2009 15:18:30 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 0/4] Memory controller soft limit patches (v3) Message-Id: <20090302151830.3770e528.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090302060519.GG11421@balbir.in.ibm.com> References: <20090301062959.31557.31079.sendpatchset@localhost.localdomain> <20090302092404.1439d2a6.kamezawa.hiroyu@jp.fujitsu.com> <20090302044043.GC11421@balbir.in.ibm.com> <20090302143250.f47758f9.kamezawa.hiroyu@jp.fujitsu.com> <20090302060519.GG11421@balbir.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: linux-mm@kvack.org, Sudhir Kumar , YAMAMOTO Takashi , Bharata B Rao , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, KOSAKI Motohiro , David Rientjes , Pavel Emelianov , Dhaval Giani , Rik van Riel , Andrew Morton List-ID: On Mon, 2 Mar 2009 11:35:19 +0530 Balbir Singh wrote: > > Then, not-sorted RB-tree can be there. > > > > BTW, > > time_after(jiffies, 0) > > is buggy (see definition). If you want make this true always, > > time_after(jiffies, jiffies +1) > > > > HZ/4 is 250/4 jiffies in the worst case (62). We have > time_after(jiffies, next_update_interval) and next_update_interval is > set to last_tree_update + 62. Not sure if I got what you are pointing > to. > + unsigned long next_update = 0; + unsigned long flags; + + if (!css_tryget(&mem->css)) + return; + prev_usage_in_excess = mem->usage_in_excess; + new_usage_in_excess = res_counter_soft_limit_excess(&mem->res); + + if (time_check) + next_update = mem->last_tree_update + + MEM_CGROUP_TREE_UPDATE_INTERVAL; + if (new_usage_in_excess && time_after(jiffies, next_update)) { + if (prev_usage_in_excess) + mem_cgroup_remove_exceeded(mem); + mem_cgroup_insert_exceeded(mem); + updated_tree = true; + } else if (prev_usage_in_excess && !new_usage_in_excess) { + mem_cgroup_remove_exceeded(mem); + updated_tree = true; + } My point is what happens if time_check==false. time_afrter(jiffies, 0) is buggy. 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