From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756117Ab0IPUFG (ORCPT ); Thu, 16 Sep 2010 16:05:06 -0400 Received: from icebox.esperi.org.uk ([81.187.191.129]:54007 "EHLO mail.esperi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754525Ab0IPUFE (ORCPT ); Thu, 16 Sep 2010 16:05:04 -0400 To: Thomas Gleixner Cc: LKML , Neil Brown , linux-nfs@vger.kernel.org Subject: Re: [PATCH RFC] x86: hpet: Avoid the readback penalty References: From: Nix Emacs: freely redistributable; void where prohibited by law. Date: Thu, 16 Sep 2010 21:04:50 +0100 In-Reply-To: (Thomas Gleixner's message of "Wed, 15 Sep 2010 15:11:57 +0200 (CEST)") Message-ID: <87d3sdfo9p.fsf@spindle.srvr.nix> User-Agent: Gnus/5.1008 (Gnus v5.10.8) XEmacs/21.5-b29 (linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-DCC-HP_X86_64_4CPU-Metrics: spindle 1245; Body=4 Fuz1=4 Fuz2=4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15 Sep 2010, Thomas Gleixner said: > On Tue, 14 Sep 2010, tip-bot for Thomas Gleixner wrote: >> x86: hpet: Work around hardware stupidity > > After my brain recovered from yesterdays exposure with the x86 timer > horror, I came up with a different solution for this problem, which > avoids the readback of the compare register completely. It works > nicely on my affected ATI system, but needs some exposure to the other > machines. > > Comments ? Works for me. (I still have boot problems, but these seem to be NFS-related: -ESTALE from an apparently random subset of my mount points at initial mount time. Restarting rpc.mountd on the server fixes it. This is with nfs-utils 1.2.2, but I see it right up to 60abb98, that being the most recent version I tested. This doesn't happen if the client is running 2.6.34.x, as far as I can tell. It also doesn't happen with all my 2.6.35.x clients. Sigh. I hate bugs like this.)