Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754533AbYAMVNU (ORCPT ); Sun, 13 Jan 2008 16:13:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753927AbYAMVNN (ORCPT ); Sun, 13 Jan 2008 16:13:13 -0500 Received: from gate.crashing.org ([63.228.1.57]:47544 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753897AbYAMVNM (ORCPT ); Sun, 13 Jan 2008 16:13:12 -0500 Subject: Re: [PATCH] mmu notifiers #v2 From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Andrea Arcangeli Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm-devel@lists.sourceforge.net, Avi Kivity , Izik Eidus , clameter@sgi.com, daniel.blueman@quadrics.com, holt@sgi.com, steiner@sgi.com, Andrew Morton , Hugh Dickins , Nick Piggin , Dave Airlie In-Reply-To: <20080113162418.GE8736@v2.random> References: <20080113162418.GE8736@v2.random> Content-Type: text/plain Date: Mon, 14 Jan 2008 08:11:44 +1100 Message-Id: <1200258704.6896.146.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1139 Lines: 29 On Sun, 2008-01-13 at 17:24 +0100, Andrea Arcangeli wrote: > Hello, > > This patch is last version of a basic implementation of the mmu > notifiers. > > In short when the linux VM decides to free a page, it will unmap it > from the linux pagetables. However when a page is mapped not just by > the regular linux ptes, but also from the shadow pagetables, it's > currently unfreeable by the linux VM. > > This patch allows the shadow pagetables to be dropped and the page to > be freed after that, if the linux VM decides to unmap the page from > the main ptes because it wants to swap out the page. Another potential user of that I can see is the DRM. Nowadays, graphic cards essentially have an MMU on chip, and can do paging. It would be nice to be able to map user objects in them without having to lock them down using your callback to properly mark them cast out on the card. Ben. -- 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/