From mboxrd@z Thu Jan 1 00:00:00 1970 From: Panagiotis Papadakos Subject: Sony CR21/Z laptop (Latency problems related to ACPI?) Date: Mon, 23 Apr 2012 15:18:48 +0300 Message-ID: <5612856.clGBGkmtMC@cray-7> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mailgate-4.ics.forth.gr ([139.91.1.7]:32388 "EHLO mailgate-4.ics.forth.gr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754483Ab2DWM3i (ORCPT ); Mon, 23 Apr 2012 08:29:38 -0400 Received: from av1.ics.forth.gr (smtp-out.ics.forth.gr. [139.91.1.71]) by mailgate-4.ics.forth.gr (8.14.5/ICS-FORTH/V10-1.9-GATE-OUT) with ESMTP id q3NCJ48e084851 for ; Mon, 23 Apr 2012 15:19:14 +0300 (EEST) Received: from cray-7.localnet (mythos@mikroulhs.ics.forth.gr [139.91.183.24] (may be forged)) (authenticated bits=0) by enigma.ics.forth.gr (8.14.3//ICS-FORTH/V10.3.0C-EXTNULL-SSL-SASL) with ESMTP id q3NCJDwq021387 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 23 Apr 2012 15:19:14 +0300 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Hello. I have been using a cr21/z laptop which probably has acpi related problems that introduce latency. I noticed it because a recent update in my Ubuntu precise makes my system's clock stay behind, and freezes my laptop when there are no mouse or keyboard actions. Somehow it looks related to https://bugzilla.kernel.org/show_bug.cgi?id=20172 If I boot my kernel with noapictimer clocksource=jiffies irqpoll options the system reacts to my actions instantly. It is the first time that I have exprerience lag free reactions from my system. Unfortunately there are spikes of 100% CPU usage, due to irq polling I assume, which makes my system less power efficient. Is there any case that we can somehow fix this problem? I am using latest git kernel. The same problem also exists in current Ubuntu precise 3.2 kernel. Thank you in advance. Panagiotis Papadakos