From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555AbXEALni (ORCPT ); Tue, 1 May 2007 07:43:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030599AbXEALni (ORCPT ); Tue, 1 May 2007 07:43:38 -0400 Received: from smtp103.mail.mud.yahoo.com ([209.191.85.213]:39075 "HELO smtp103.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754536AbXEALnh (ORCPT ); Tue, 1 May 2007 07:43:37 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=aekRssZi7OJEV58bOuzj2g3Rhg/KDtqApkfU2iMZMPAWdigRWri0TWCAc75Lgj1kSPlgCzcjJBeGaT9+YbYb+6w0TRIspVvoLziU3s8Y+eG9iEBdaQbv/UKh6ZsXQxGRSpK2c3GMlGAfUy2r922ef24tHPNZbbz/T3/3BKZtrYo= ; X-YMail-OSG: 0UGcEl8VM1lRAHcLoEfO.9jTcDyyr8sUAI6wBn64yL7ck8iagxUIuDHxCJhTzF_Q2sMSCVYmpA-- Message-ID: <463727E1.3090203@yahoo.com.au> Date: Tue, 01 May 2007 21:43:29 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Rohit Seth CC: "'Hugh Dickins'" , "'Mike Stroyan'" , "'Andrew Morton'" , "'Luck, Tony'" , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path References: <200704281805.l3SI5JQx030827@smtp.corp.google.com> In-Reply-To: <200704281805.l3SI5JQx030827@smtp.corp.google.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Rohit Seth wrote: > > > -----Original Message----- > From: Hugh Dickins [mailto:hugh@veritas.com] > Sent: Friday, April 27, 2007 10:20 PM > To: Nick Piggin > Cc: rohitseth@google.com; Mike Stroyan; Andrew Morton; Luck, Tony; > linux-ia64@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path > > On Sat, 28 Apr 2007, Nick Piggin wrote: > >>OIC, you need a virtual address to evict the icache, so you can't >>flush at flush_dcache time? Or does ia64 have an instruction to flush >>the whole icache? (it would be worth testing, to see how much >>performance suffers). > > > IIRC, there is a PAL call to flush the whole cache (but that is quite a > heavy call). Though you really don't need to be doing this. > > >>I'm puzzled by that remark: the ia64 flush_icache_range always has a >>virtual address, it uses the kernel virtual address; it takes >>no interest in whether there's a user virtual address. > > > Caches on Itanium are physical. So, it doesn't matter what virtual address > you use to flush a cache line, cache line containing specific physical > memory will be flushed. Really? I was under the vague impression that L1 i/d caches were virtual and required this flushing... but I guess so long as the ISA says that fc/fc.i flushes all caches corresponding to the physical address of the provided virtual address, then that's what matters. > For the cases where you have virtual caches, > update_mmu_cache is the API to use. But it happens after the pte is installed. -- SUSE Labs, Novell Inc.