From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762077AbXGDOYq (ORCPT ); Wed, 4 Jul 2007 10:24:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760505AbXGDOYi (ORCPT ); Wed, 4 Jul 2007 10:24:38 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:56275 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758497AbXGDOYh (ORCPT ); Wed, 4 Jul 2007 10:24:37 -0400 Message-ID: <468BADA6.9050609@bull.net> Date: Wed, 04 Jul 2007 16:24:38 +0200 From: Zoltan Menyhart User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040913 X-Accept-Language: en-us, en, fr, hu MIME-Version: 1.0 To: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 04/07/2007 16:28:48, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 04/07/2007 16:28:49, Serialize complete at 04/07/2007 16:28:49 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Could you please confirm that I understand correctly what is in the: Dual-Core Update to the Intel Itanium 2 Processor Reference Manual... "2.3.3.2 L2 Caches ... Any coherence request to identify whether a cache line is in the processor will invalidate that line from the L2I cache." This makes sure that the DMAs invalidate the L2L cache. "2.7.4 Instruction Cache Coherence Optimization Coherence requests of the L1I and L2I caches will invalidate the line if it is in the cache. Montecito allows instruction requests on the system interface to be filtered such that they will not initiate coherence requests of the L1I and L2I caches. This will allow instructions to be cached at the L1I and L2I levels across multiple processors in a coherent domain. This optimization is enabled by default, but may be disabled by PAL_SET_PROC_FEATURES bit 5 of the Montecito feature_set (18)." Machines star up whit bit 5 = 0, reading instruction pages via NFS has to flush them from L2I. I was wondering if instead of modifying do_no_page() and Co., should not we make nfs_readpage() be DMA-like? (No possible regression for most of the page I/O-s.) I.e. it should be the responsibility of a file system to make sure it supports instruction pages correctly. The base kernel should provide such file systems with an architecture dependent macro... Thanks, Zoltan Menyhart