From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carsten Emde Subject: Re: Latency problem Date: Thu, 27 Oct 2011 23:15:35 +0200 Message-ID: <4EA9C9F7.9090902@osadl.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-rt-users@vger.kernel.org To: =?ISO-8859-1?Q?Rapha=EBl_Beamonte?= Return-path: Received: from toro.web-alm.net ([62.245.132.31]:36101 "EHLO toro.web-alm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751917Ab1J0Vjc (ORCPT ); Thu, 27 Oct 2011 17:39:32 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: Rapha=EBl, > [..] >> root@USBnux:/home/xaf/RT/rt-tests# ./hwlatdetect --threshold=3D1 --r= eport=3D/home/xaf/hwlat_report >> hwlatdetect: test duration 120 seconds >> parameters: >> Latency threshold: 1us >> >> Sample window: 1000000us >> Sample width: 500000us >> Non-sampling period: 500000us >> Output File: /home/xaf/hwlat_report >> Starting test >> test finished >> Max Latency: 38136us >> Samples recorded: 45 >> Samples exceeding threshold: 45 >> sample data written to /home/xaf/hwlat_report > > and the content of the hwlat_report file : > >> 1319575592.0802426354 19061 >> 1319575707.0402420761 19036 > [..] > I really have no idea from where the problem could be. And I need you= r > lights to help me. The hwlatdetect application detects system management interrupts (SMIs)= =2E=20 Such interrupts are installed by the BIOS and are used to manage variou= s=20 things such as battery management, overheat protection and emulation of= =20 legacy devices (e.g. IDE, PS/2 etc.). You may try to check your BIOS=20 settings and disable all these or similar features. Then run hwlatdetec= t=20 again. If it still reports SMIs, the next thing to do depends on the=20 promises that you got when you bought the board: 1. It was advertised as an industrial PC to be used in a control system= s=20 and to run a real-time operating system: Return the board to the manufacturer along with the printed output of=20 hwlatdetect and ask for a fix or your money back. 2. It is a standard server PC board without any promises as to its=20 suitability in a real-time system: There probably is nothing you can do. Try to send the output of=20 hwlatdetect to the BIOS manufacturer and nicely ask for a fixed BIOS,=20 but I am not very optimistic that you will get one. Hope this helps, -Carsten. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html