From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266533AbUBGDDq (ORCPT ); Fri, 6 Feb 2004 22:03:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266546AbUBGDDq (ORCPT ); Fri, 6 Feb 2004 22:03:46 -0500 Received: from pirx.hexapodia.org ([65.103.12.242]:15279 "EHLO pirx.hexapodia.org") by vger.kernel.org with ESMTP id S266533AbUBGDDo (ORCPT ); Fri, 6 Feb 2004 22:03:44 -0500 Date: Fri, 6 Feb 2004 21:03:43 -0600 From: Andy Isaacson To: Jamie Lokier Cc: linux-kernel@vger.kernel.org Subject: Re: avoiding dirty code pages with fixups Message-ID: <20040207030343.GB21565@hexapodia.org> References: <20040203225453.GB18320@hexapodia.org> <20040207001317.GE12503@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040207001317.GE12503@mail.shareable.org> User-Agent: Mutt/1.4.1i X-PGP-Fingerprint: 48 01 21 E2 D4 E4 68 D1 B8 DF 39 B2 AF A3 16 B9 X-PGP-Key-URL: http://web.hexapodia.org/~adi/pgp.txt X-Domestic-Surveillance: money launder bomb tax evasion Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 07, 2004 at 12:13:17AM +0000, Jamie Lokier wrote: > > The downside is the additional computation on page-in. > > > It is a function of how many fixups there are per page, and of how > > much work ld.so does to satisfy a fixup. I don't have a good feel > > for how expensive ld.so's fixup mechanism is... any comments? > > The other downside of your idea is that every instance of a program > has more dirty pages. While it is true that the pages do not require > disk I/O, they still take up RAM that could be used for other page > cache things. Well, in the case I describe, currently they're done with MAP_PRIVATE mappings, so it's no net loss. -andy