Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753166Ab0DINdJ (ORCPT ); Fri, 9 Apr 2010 09:33:09 -0400 Received: from cantor2.suse.de ([195.135.220.15]:35499 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752444Ab0DINdB (ORCPT ); Fri, 9 Apr 2010 09:33:01 -0400 Date: Fri, 9 Apr 2010 15:32:59 +0200 (CEST) From: Jiri Kosina To: =?ISO-8859-15?Q?=C9ric_Piel?= Cc: Andrew Morton , Samu Onkalo , Pavel Machek , lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org, Marcin Derlukiewicz Subject: Re: [PATCH] lis3lv02d: provide means to disable polled input interface In-Reply-To: <4BBF2BD1.5050107@tremplin-utc.net> Message-ID: References: <4BBF2BD1.5050107@tremplin-utc.net> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1474 Lines: 35 On Fri, 9 Apr 2010, ?ric Piel wrote: > > This is reported to create 20% CPU usage increase (and proportionaly higher > > power consumption) just for the ipolldevd kernel thread (which is used > > to read the sensor). > > > > As most users probably only use the freefall functionality of the driver > > and not the joystick interface, provide means for disabling the registration > > of joystick device altogether via module parameter. > > (I'd rather make it default to 0, but this will break backwards compatibility). > Are you saying there is a 20% CPU usage even when the joystick interface > is not open? This should not happen (and this is not happening on my > laptop). The polling should happen only when a userspace app opens the > joystick interface (like running neverball). > > So I'd tend to think it's more due to a misconfiguration of the system > (like xserver using the joystick interface as a pointer device) or it's > a bug in the way we set up the polling. Could you investigate and let me > know? Marcin originally reported this to me. Marcin, could you please check 'lsof' output to see whether the joystick interface has been open by some application? Thanks, -- Jiri Kosina SUSE Labs, Novell Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/