From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislav Meduna Subject: Re: Random 3 to 4.5 second blocks of RT thread Date: Mon, 11 Feb 2013 19:55:53 +0100 Message-ID: <51193EB9.2060409@meduna.org> References: <8426D3F6-9553-4B6A-B318-4983625ACC8E@bj-ig.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Realtime Mailinglist , Thomas Weisser To: =?ISO-8859-1?Q?Ralf_M=FCller?= Return-path: Received: from www.meduna.org ([92.240.244.38]:60377 "EHLO meduna.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759371Ab3BKS4D (ORCPT ); Mon, 11 Feb 2013 13:56:03 -0500 In-Reply-To: <8426D3F6-9553-4B6A-B318-4983625ACC8E@bj-ig.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 11.02.2013 16:54, Ralf M=FCller wrote: > It basically is a loop that wakes up every milli second, increments a > generation counter, does some statistics and goes to sleep for > another millisecond. 3-4.5 seconds is heavy so this is not very probable, but seeing that you have a thread with prio 99 and have timer wakeup problems, depending on what the other realtime threads do maybe the following could be (part of) the issue: http://www.spinics.net/lists/linux-rt-users/msg08745.html http://www.spinics.net/lists/linux-rt-users/msg07804.html Shortly said: you aren't going to have low latency timers if the ksoftirqd can be preempted by your threads. Disclaimer: I have never used RT with 2.6, so I don't know whether it applies at all. Regards --=20 Stano -- 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