Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262381AbVEMOY4 (ORCPT ); Fri, 13 May 2005 10:24:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262379AbVEMOY4 (ORCPT ); Fri, 13 May 2005 10:24:56 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:62109 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S262381AbVEMOYe (ORCPT ); Fri, 13 May 2005 10:24:34 -0400 Subject: Re: [RFC] Cachemap for 2.6.12rc4-mm1. Was Re: [PATCH] enhance x86 MTRR handling From: Dave Hansen To: Andi Kleen Cc: Dave Jones , Linux Kernel Mailing List , tripperda@nvidia.com In-Reply-To: <20050513132945.GB16088@wotan.suse.de> References: <20050512161825.GC17618@redhat.com> <20050512214118.GA25065@redhat.com> <20050513132945.GB16088@wotan.suse.de> Content-Type: text/plain Date: Fri, 13 May 2005 07:24:22 -0700 Message-Id: <1115994262.7129.22.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1360 Lines: 36 On Fri, 2005-05-13 at 15:29 +0200, Andi Kleen wrote: > > : x86-64 will need updating to also take advantage of this. > > It may be able to just copy the i386 includes as-is, I've > > not looked closely at the PAT related changes on x86-64 yet. Andi? > > > > : The list manipulation macros in mm/cachemap.c are a little fugly. > > > > Anything else ? > > For memory (pfn_valid == 1) it would be more memory efficient to use a few bits > in struct page->flags I think page->flags use should be limited to things that are relatively performance-sensitive and arch-independent, mostly because we're running out of them on 32-bit platforms, fast. Each incremental use of page flags doesn't have any immediate storage cost, but it's a serious pain when we run out, and having to bloat it to a 64-bit value on 32-bit platforms wouldn't be very memory efficient, either. :) > In general because there are lots of uses of "range lists" it would be better > to put it as a library into lib. Either that, or something like "Dynamically allocated pageflags" would be nice. http://lwn.net/Articles/124332/ -- Dave - 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/