From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755434AbXFTFIh (ORCPT ); Wed, 20 Jun 2007 01:08:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758406AbXFTFI3 (ORCPT ); Wed, 20 Jun 2007 01:08:29 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:41773 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756041AbXFTFI2 (ORCPT ); Wed, 20 Jun 2007 01:08:28 -0400 Date: Tue, 19 Jun 2007 22:08:25 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Paul Mundt cc: linux-mm@kvack.org, wli@holomorphy.com, lee.schermerhorn@hp.com, linux-kernel@vger.kernel.org Subject: Re: Some thoughts on memory policies In-Reply-To: <20070620040131.GA29240@linux-sh.org> Message-ID: References: <20070620040131.GA29240@linux-sh.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 Jun 2007, Paul Mundt wrote: > There's quite a bit of room for improving and extending the existing > code, and those options should likely be exhausted first. There is a confusing maze of special rules if one goes beyond the simple process address space case. There are no clean rules on how to combine memory policies. Refcounting / updating becomes a problem because policies are intended to be only updated from the process that set them up. Look at the gimmicks that Paul needed to do to update memory policies when a process is migrated and the vmas on the stack for shmem etc etc.