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 964376B01FA for ; Tue, 30 Mar 2010 02:09:34 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o2U68sOp022110 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 30 Mar 2010 15:08:54 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 71C2845DE4F for ; Tue, 30 Mar 2010 15:08:54 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 4D31E45DE53 for ; Tue, 30 Mar 2010 15:08:54 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 210DF1DB803A for ; Tue, 30 Mar 2010 15:08:54 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id BE0441DB8044 for ; Tue, 30 Mar 2010 15:08:53 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH]vmscan: handle underflow for get_scan_ratio In-Reply-To: <20100330055304.GA2983@sli10-desk.sh.intel.com> References: <20100330055304.GA2983@sli10-desk.sh.intel.com> Message-Id: <20100330150453.8E9F.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 30 Mar 2010 15:08:53 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Shaohua Li Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, fengguang.wu@intel.com List-ID: Hi > Commit 84b18490d1f1bc7ed5095c929f78bc002eb70f26 introduces a regression. > With it, our tmpfs test always oom. The test has a lot of rotated anon > pages and cause percent[0] zero. Actually the percent[0] is a very small > value, but our calculation round it to zero. The commit makes vmscan > completely skip anon pages and cause oops. > An option is if percent[x] is zero in get_scan_ratio(), forces it > to 1. See below patch. > But the offending commit still changes behavior. Without the commit, we scan > all pages if priority is zero, below patch doesn't fix this. Don't know if > It's required to fix this too. Can you please post your /proc/meminfo and reproduce program? I'll digg it. Very unfortunately, this patch isn't acceptable. In past time, vmscan had similar logic, but 1% swap-out made lots bug reports. -- 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