From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935512AbYDQJ56 (ORCPT ); Thu, 17 Apr 2008 05:57:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763785AbYDQJaF (ORCPT ); Thu, 17 Apr 2008 05:30:05 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:36805 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934090AbYDQJaB (ORCPT ); Thu, 17 Apr 2008 05:30:01 -0400 Date: Thu, 17 Apr 2008 18:30:11 +0900 From: KOSAKI Motohiro To: "Tom May" Subject: Re: [PATCH 0/8][for -mm] mem_notify v6 Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: References: <20080402154910.9588.KOSAKI.MOTOHIRO@jp.fujitsu.com> Message-Id: <20080417182121.A8CA.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tom > Here's a test program that allocates memory and frees on notification. > It takes an argument which is the number of pages to use; use a > number considerably higher than the amount of memory in the system. > I'm running this on a system without swap. Each time it gets a > notification, it frees memory and writes out the /proc/meminfo > contents. What I see is that Cached gradually decreases, then Mapped > decreases, and eventually the kernel invokes the oom killer. It may > be necessary to tune some of the constants that control the allocation > and free rates and latency; these values work for my system. may be... I think you misunderstand madvise(MADV_DONTNEED). madvise(DONTNEED) indicate drop process page table. it mean become easily swap. when run on system without swap, madvise(DONTNEED) almost doesn't work as your expected. I am sorry for being not able to help you. ;)