From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: High latencies with linux-2.6.25.4-rt6 on MPC5200 Date: Wed, 18 Jun 2008 10:07:05 +0200 Message-ID: <4858C229.2060509@grandegger.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: RT Return-path: Received: from mail-out.m-online.net ([212.18.0.9]:40266 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbYFRIHD (ORCPT ); Wed, 18 Jun 2008 04:07:03 -0400 Received: from mail01.m-online.net (mail.m-online.net [192.168.3.149]) by mail-out.m-online.net (Postfix) with ESMTP id 21745439693 for ; Wed, 18 Jun 2008 10:07:04 +0200 (CEST) Received: from lancy.denx.de (p5497CFFA.dip.t-dialin.net [84.151.207.250]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp-auth.mnet-online.de (Postfix) with ESMTP id 79CAA90171 for ; Wed, 18 Jun 2008 10:07:02 +0200 (CEST) Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hello, I currently re-doing latency measurement with my TQM5200 board under Linux 2.6.25. With 2.6.24-rt1 "cyclictest -n -p80 -i1000 -t1" reported a maximum latency of 170us. With 2.6.25.4-rt5 I'm unable to reproduce such reasonable latencies. cyclictest shows quickly latencies up to 600 us. What has changed in the meantime? Any ideas how to get better latencies? Wolfgang.