From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934015AbXC1WqH (ORCPT ); Wed, 28 Mar 2007 18:46:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933807AbXC1WqH (ORCPT ); Wed, 28 Mar 2007 18:46:07 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:44469 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934055AbXC1WqG (ORCPT ); Wed, 28 Mar 2007 18:46:06 -0400 Date: Wed, 28 Mar 2007 15:45:39 -0700 From: Chris Wright To: William Lee Irwin III Cc: Chris Wright , Christoph Lameter , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, jeremy@goop.org, zach@vmware.com Subject: Re: [RFC] i386: Remove page sized slabs for pgds and pmds Message-ID: <20070328224539.GJ10574@sequoia.sous-sol.org> References: <20070328222656.GS6602@sequoia.sous-sol.org> <20070328223327.GG2986@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070328223327.GG2986@holomorphy.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * William Lee Irwin III (wli@holomorphy.com) wrote: > * Christoph Lameter (clameter@sgi.com) wrote: > >> +#ifdef CONFIG_HIGHMEM64G > >> +#define __pgd_alloc() kmem_cache_alloc(pgd_cache, GFP_KERNEL|__GFP_REPEAT) > >> +#define __pgd_free(pgd) kmem_cache_free(pgd_cache, pgd) > > On Wed, Mar 28, 2007 at 03:26:56PM -0700, Chris Wright wrote: > > I must've glazed over something, I thought this was removal of slabs? > > The pgd slab is not fully removable in the PAE case because a dedicated > slab is the only way to enforce alignment for allocations as small as > PAE PGD's. Heh, yeah "page sized" is the part i glazed over, my fault. > On Wed, Mar 28, 2007 at 03:26:56PM -0700, Chris Wright wrote: > > BTW, this will interact shared_kernel_pmd patch that Jeremy's posted a > > few times (I know at least wli has looked over that one). We need to > > make sure that PAE under at least Xen hypervisor has a page-sized pgd, > > although the mmlist chaining looks nice to me. > > That, not to mention the total lack of verification of the pageattr.c > code, are among the reasons I didn't want it posted. > > > * Christoph Lameter (clameter@sgi.com) wrote: > >> + memcpy(&pgd[USER_PTRS_PER_PGD], &swapper_pg_dir[USER_PTRS_PER_PGD], > >> + KERNEL_PGD_PTRS*sizeof(pgd_t)); > > On Wed, Mar 28, 2007 at 03:26:56PM -0700, Chris Wright wrote: > > clone_pgd_range() for consistency? and it seems we lost a > > paravirt_alloc_pd_clone() in there somewhere. > > Yes, another reason why it shouldn't have been posted as-is. It was not > intended to for anything more than comparative benchmarking on systems > without graphics running on the bare metal as opposed to Xen/etc. guests. OK, all good here. Just wanted to make sure things didn't collide too badly. thanks, -chris