From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263949AbUDFSlp (ORCPT ); Tue, 6 Apr 2004 14:41:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263950AbUDFSlp (ORCPT ); Tue, 6 Apr 2004 14:41:45 -0400 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:31123 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S263949AbUDFSln (ORCPT ); Tue, 6 Apr 2004 14:41:43 -0400 Date: Tue, 6 Apr 2004 20:41:41 +0200 From: Andrea Arcangeli To: Manfred Spraul Cc: Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: -mmX 4G patches feedback [numbers: how much performance impact] Message-ID: <20040406184141.GH2234@dualathlon.random> References: <4072EFEE.6050907@colorfullife.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4072EFEE.6050907@colorfullife.com> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 06, 2004 at 07:59:10PM +0200, Manfred Spraul wrote: > Does AMD document how the CAM filter actually works? x86-64 writes into > the 4th level page table during a context switch and if I understand the > patent description correctly, this defeates the flush filter and forces > a full flush during a context switch. this is something we discussed a few times during the early x86-64 development. The main question you should answer is what gains you to do a partial flush if the only non global entries have to be flushed anyways?