From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752256AbXBXMtD (ORCPT ); Sat, 24 Feb 2007 07:49:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752273AbXBXMtD (ORCPT ); Sat, 24 Feb 2007 07:49:03 -0500 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:37805 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752256AbXBXMtB (ORCPT ); Sat, 24 Feb 2007 07:49:01 -0500 Date: Sat, 24 Feb 2007 13:52:52 +0000 From: Alan To: "Stephen Dolan" Cc: linux-kernel@vger.kernel.org Subject: Re: Memory sharing question Message-ID: <20070224135252.21caa191@lxorguk.ukuu.org.uk> In-Reply-To: <1eff86fb0702240350l2c111c2apb5639fec67b360b4@mail.gmail.com> References: <1eff86fb0702240350l2c111c2apb5639fec67b360b4@mail.gmail.com> X-Mailer: Claws Mail 2.7.2 (GTK+ 2.10.8; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > with the address as the "start" parameter and MAP_FIXED. However, that > tends to fail, and MAP_FIXED can have annoying side-effects (killing > off other mappings). MAP_FIXED requires you know in advance a good place to put the memory, which isn't too hard with some planning but does get fairly platform specific and requires good knowledge. > The point of all this is that I want to pass a large, complex (full of > pointers) data structure to a different process, and I don't want the > overhead of serialising it down a socket and then parsing it at the > other end (the data structure's pretty big, and the other process > won't need it all). Is this possible? You can also just use relative pointers, which is actually pretty fast on most modern processors