From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933648AbXC1WhT (ORCPT ); Wed, 28 Mar 2007 18:37:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933814AbXC1WhT (ORCPT ); Wed, 28 Mar 2007 18:37:19 -0400 Received: from holomorphy.com ([66.93.40.71]:47496 "EHLO holomorphy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933648AbXC1WhS (ORCPT ); Wed, 28 Mar 2007 18:37:18 -0400 Date: Wed, 28 Mar 2007 15:33:27 -0700 From: William Lee Irwin III To: Chris Wright Cc: 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: <20070328223327.GG2986@holomorphy.com> References: <20070328222656.GS6602@sequoia.sous-sol.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070328222656.GS6602@sequoia.sous-sol.org> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * 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. 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. -- wli