Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758335Ab0DPMN1 (ORCPT ); Fri, 16 Apr 2010 08:13:27 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:15025 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758287Ab0DPMNZ convert rfc822-to-8bit (ORCPT ); Fri, 16 Apr 2010 08:13:25 -0400 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes To: samu.p.onkalo@nokia.com, jkosina@suse.cz, eric.piel@tremplin-utc.net Cc: akpm@linux-foundation.org, pavel@ucw.cz, lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] lis3lv02d: provide means to disable polled input interface References: <4BBF2BD1.5050107@tremplin-utc.net> <62697B07E9803846BC582181BD6FB6B826A8525E8A@NOK-EUMSG-02.mgdnok.nokia.com> Date: Fri, 16 Apr 2010 14:13:21 +0200 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT From: "Marcin Derlukiewicz" Message-ID: In-Reply-To: <62697B07E9803846BC582181BD6FB6B826A8525E8A@NOK-EUMSG-02.mgdnok.nokia.com> User-Agent: Opera Mail/10.10 (Linux) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2580 Lines: 79 Dnia 16-04-2010 o 14:00:15 napisał(a): > > >> -----Original Message----- >> From: ext Marcin Derlukiewicz [mailto:marcin@derlukiewicz.pl] >> Sent: 16 April, 2010 14:42 >> To: Jiri Kosina; Éric Piel >> Cc: Andrew Morton; Onkalo Samu.P (Nokia-D/Tampere); Pavel Machek; lm- >> sensors@lm-sensors.org; linux-kernel@vger.kernel.org >> Subject: Re: [PATCH] lis3lv02d: provide means to disable polled input >> interface >> >> Dnia 09-04-2010 o 15:32:59 Jiri Kosina napisał(a): >> >>> On Fri, 9 Apr 2010, Éric 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, >>> >> >> sorry for the delay, had a crunch time >> >> here is the link for this lsof: >> https://bugzilla.novell.com/attachment.cgi?id=354953 >> > > Could you check what is the polling period of the device. > something like: > cat /sys/devices/platform/lis3lv02d/input/input9/poll > > it is current polling period in milliseconds. 0 disables polling. > > -Samu > I think that on my system this is /sys/devices/platform/lis3lv02d/rate but i may be wrong. Anyway it contains 40 as a number. Marcin. -- 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/