From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kirk.dutchspace.nl (kirk.dutchspace.nl [193.200.147.14]) by ozlabs.org (Postfix) with ESMTP id 98FBDDDE43 for ; Thu, 6 Sep 2007 17:43:15 +1000 (EST) Message-ID: <46DFAF91.3060102@dutchspace.nl> Date: Thu, 06 Sep 2007 09:43:13 +0200 From: Johan Borkhuis MIME-Version: 1.0 To: Wolfgang Denk Subject: Re: Problems enabling NTP on ELDK References: <20070905184827.26859247AF@gemini.denx.de> In-Reply-To: <20070905184827.26859247AF@gemini.denx.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Wolfgang Denk wrote: > In message <46DE9322.7080901@dutchspace.nl> you wrote: > >> I tried enabling NTP on my embedded machine (using ELDK 4.1, ppc_85xx, >> kernel version 2.6.14 with Xenomai 2.3.2). After I did that I noticed >> that ksoftirqd/0 suddenly took almost all processor time (> 95%). What >> is causing this? Is there a way around this, or is this something that >> does not cause any problems? >> > > You probably have some poroblems in your kernel port - check the RTC > driver and related modules like I2C etc. Of course this depends on > the NTP configuration you use, but the only kernel interaction I can > think of that could cause this is if you interact with the RTC. [I > guess that normal network traffic is working fine on your board.] > All other functions are working fine: no problem with network or other PCI devices. I disabled all RTC and I2C devices, and the problem disappeared. After enabling all items one by one the cause of the problem seems to be the DS1375 RTC: after I enable this and start NTPD ksoftirqd goes wild again. I do not see any other special activity: no extra interrupts in /proc/interrupts, and also no other RTC related errors or messages. Also OpenPIC does not show any extra interrupts. Is there a way to find out what interrupt is causing ksoftirqd to be triggered? > BTW: ELDK 4.1 comes with a 2.6.19.2 kernel - is there a special > reason that you use such an obsoletel kernel tree? > I am using an MVME3100 board together with Xenomai. This board has support for version 2.6.14-ppc and 2.6.20-ppc, while Xenomai/Adeos is supported on 2.6.14 and 2.6.19. I did not yet find time to backport the support to 2.6.19. Kind regards, Johan Borkhuis