From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23038 invoked by alias); 20 Oct 2004 23:25:54 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 23025 invoked from network); 20 Oct 2004 23:25:53 -0000 Received: from unknown (HELO nevyn.them.org) (66.93.172.17) by sourceware.org with SMTP; 20 Oct 2004 23:25:53 -0000 Received: from drow by nevyn.them.org with local (Exim 4.34 #1 (Debian)) id 1CKPq1-0003ug-Ak; Wed, 20 Oct 2004 19:25:49 -0400 Date: Thu, 21 Oct 2004 12:52:00 -0000 From: Daniel Jacobowitz To: Hans Zuidam Cc: gdb@sources.redhat.com Subject: Re: Thread debugging and scheduling behaviour Message-ID: <20041020232548.GA14896@nevyn.them.org> Mail-Followup-To: Hans Zuidam , gdb@sources.redhat.com References: <4C340065-22ED-11D9-9E9C-00039359816C@wanadoo.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C340065-22ED-11D9-9E9C-00039359816C@wanadoo.nl> User-Agent: Mutt/1.5.5.1+cvs20040105i X-SW-Source: 2004-10/txt/msg00391.txt.bz2 On Thu, Oct 21, 2004 at 01:10:56AM +0200, Hans Zuidam wrote: > Hi, > > When running a simple multi-threaded test outside and inside GDB we > see different scheduling behaviour. This is on a Linux 2.4.20 system. > > Specifically the test uses SCHED_FIFO scheduling and fixed priorities. > What we see is that when run outside GDB the higher priority threads > run first until they yield, while running in GDB (just a `run' no > breakpoints) causes low priority threads to run before high priority > ones. > > Is this "expected" Linux behaviour or does it have something to do > with the thread handling in GDB? Any pointers are greatly appreciated. GDB does not have any way to support thread priority. -- Daniel Jacobowitz