From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 22 Sep 2001 09:02:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 22 Sep 2001 09:01:43 -0400 Received: from mailc.telia.com ([194.22.190.4]:3814 "EHLO mailc.telia.com") by vger.kernel.org with ESMTP id ; Sat, 22 Sep 2001 09:01:41 -0400 Message-Id: <200109221301.f8MD1n129687@mailc.telia.com> Content-Type: text/plain; charset="iso-8859-1" From: Roger Larsson To: Robert Love , Andre Pang , Andrea Arcangeli Subject: ksoftirqd? (Was: Re: [PATCH] Preemption Latency Measurement Tool) Date: Sat, 22 Sep 2001 14:56:58 +0200 X-Mailer: KMail [version 1.3.1] Cc: linux-kernel@vger.kernel.org, safemode@speakeasy.net, Dieter.Nuetzel@hamburg.de, iafilius@xs4all.nl, ilsensine@inwind.it, george@mvista.com In-Reply-To: <1000939458.3853.17.camel@phantasy> <1001131036.557760.4340.nullmailer@bozar.algorithm.com.au> <1001139027.1245.28.camel@phantasy> In-Reply-To: <1001139027.1245.28.camel@phantasy> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, We have a new kid on the block since we started thinking of a preemptive kernel. ksoftirqd... Running with nice 19 (shouldn't it really be -19?) Or have a RT setting? (maybe not since one of the reasons for softirqd would be lost - would be scheduled in immediately) Can't a high prio or RT process be starved due to missing service (bh) after an interrupt? This will not show up in latency profiling patches since the kernel does what is requested... Previously it was run directly after interrupt, before returning to the interrupted process... See: /usr/src/develop/linux/kernel/softirq.c /RogerL -- Roger Larsson Skellefteċ Sweden