From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756812Ab0DFBWQ (ORCPT ); Mon, 5 Apr 2010 21:22:16 -0400 Received: from mga11.intel.com ([192.55.52.93]:3968 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756532Ab0DFBWJ (ORCPT ); Mon, 5 Apr 2010 21:22:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.51,368,1267430400"; d="scan'208";a="555219306" Date: Tue, 6 Apr 2010 09:22:07 +0800 From: Wu Fengguang To: KOSAKI Motohiro Cc: Andrew Morton , "Li, Shaohua" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH]vmscan: handle underflow for get_scan_ratio Message-ID: <20100406012206.GD5295@localhost> References: <20100331145602.03A7.A69D9226@jp.fujitsu.com> <20100401151639.a030fb10.akpm@linux-foundation.org> <20100402180812.646D.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100402180812.646D.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > =================================================================== > >From 52358cbccdfe94e0381974cd6e937bcc6b1c608b Mon Sep 17 00:00:00 2001 > From: KOSAKI Motohiro > Date: Fri, 2 Apr 2010 17:13:48 +0900 > Subject: [PATCH] Revert "vmscan: get_scan_ratio() cleanup" > > Shaohua Li reported his tmpfs streaming I/O test can lead to make oom. > The test uses a 6G tmpfs in a system with 3G memory. In the tmpfs, > there are 6 copies of kernel source and the test does kbuild for each > copy. His investigation shows the test has a lot of rotated anon > pages and quite few file pages, so get_scan_ratio calculates percent[0] > (i.e. scanning percent for anon) to be zero. Actually the percent[0] > shoule be a big value, but our calculation round it to zero. should small :) Acked-by: Wu Fengguang Thanks, Fengguang