From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752619AbYE1QEe (ORCPT ); Wed, 28 May 2008 12:04:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751340AbYE1QEZ (ORCPT ); Wed, 28 May 2008 12:04:25 -0400 Received: from fg-out-1718.google.com ([72.14.220.154]:49733 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751169AbYE1QEZ (ORCPT ); Wed, 28 May 2008 12:04:25 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=Pz1N/ek35nyoEKcURvoLYa/G84iTiIeH54IWsJ0pvwNo/PAF6RSgA5lFjunFHXAURSIC6xqronvCVOo59gGmUdhfiI93UVk49+cBq8yXg4K4Z3dUFBWft/VLU78kNfJq0dgp2OiFcsQdOzoQcnNfOhVfptJF735K1AG9U+p3TeE= Date: Wed, 28 May 2008 20:04:13 +0400 From: Cyrill Gorcunov To: "Maciej W. Rozycki" Cc: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [patch 06/11] x86: nmi_32/64.c - use apic_write_around instead of apic_write Message-ID: <20080528160413.GA6910@cvg> References: <20080524153630.669797039@gmail.com>> <48383740.0407560a.4764.7d1b@mx.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Maciej W. Rozycki - Wed, May 28, 2008 at 04:35:14PM +0100] | On Sat, 24 May 2008, Cyrill Gorcunov wrote: | | > apic_write_around will be expanded to apic_write in 64bit mode | > anyway. Only a few CPUs (well, old CPUs to be precise) requires | > such an action. In general it should not hurt and could be cleaned | > up for apic_write (just in case) | > | > Signed-off-by: Cyrill Gorcunov | > --- | | Acked-by: Maciej W. Rozycki | | Almost all local APIC write accesses must use apic_write_around(). The | notable exceptions are appropriately guarded accesses to the ESR (there is | no need ever to write to this register on Pentium processors and a read of | the register has side-effects) and pieces of code known never to run on | original Pentium processors. | | Maciej | Thanks Maciej! Could you take a look please on http://lkml.org/lkml/2008/5/26/146 i'm investigateting what is happening (Adrian pointed on main reason I think) but can't understand why is that. - Cyrill -