Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261236AbTIBL3n (ORCPT ); Tue, 2 Sep 2003 07:29:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261273AbTIBL3n (ORCPT ); Tue, 2 Sep 2003 07:29:43 -0400 Received: from holomorphy.com ([66.224.33.161]:52972 "EHLO holomorphy") by vger.kernel.org with ESMTP id S261236AbTIBL3l (ORCPT ); Tue, 2 Sep 2003 07:29:41 -0400 Date: Tue, 2 Sep 2003 04:30:38 -0700 From: William Lee Irwin III To: Takao Indoh Cc: Mike Fedyk , linux-kernel@vger.kernel.org Subject: Re: cache limit Message-ID: <20030902113038.GK4306@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Takao Indoh , Mike Fedyk , linux-kernel@vger.kernel.org References: <20030827113646.GC4306@holomorphy.com> <23C371405B0858indou.takao@soft.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <23C371405B0858indou.takao@soft.fujitsu.com> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1692 Lines: 42 On Tue, Sep 02, 2003 at 07:52:51PM +0900, Takao Indoh wrote: > According to this information, many I/O increase pagecache and cause > memory shortage. > fadvise may be effective, but fadvise always releases cache > even if there are enough free memory, and may degrade performance. > In the case of /proc tunable, > pagecache is not released until system memory become lack. [...] > If so, limiting pagecache seems to be effective for DBMS. There are reasons why databases use raw io and direct io; this is one of them. I'd say the kernel shouldn't try to engage in such tunable shenanigans. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ On Tue, Sep 02, 2003 at 07:52:51PM +0900, Takao Indoh wrote: > According to this information, many I/O increase pagecache and cause > memory shortage. > fadvise may be effective, but fadvise always releases cache > even if there are enough free memory, and may degrade performance. > In the case of /proc tunable, > pagecache is not released until system memory become lack. [...] > If so, limiting pagecache seems to be effective for DBMS. There are reasons why databases use raw io and direct io; this is one of them. I'd say the kernel shouldn't try to engage in such tunable shenanigans. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/