From owner-freebsd-hackers Mon Nov 10 15:47:53 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id PAA08465 for hackers-outgoing; Mon, 10 Nov 1997 15:47:53 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from kinclaith.pdl.cs.cmu.edu (KINCLAITH.PDL.CS.CMU.EDU [128.2.189.18]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id PAA08446 for ; Mon, 10 Nov 1997 15:47:37 -0800 (PST) (envelope-from dpetrou@kinclaith.pdl.cs.cmu.edu) Message-Id: <199711102347.PAA08446@hub.freebsd.org> Subject: microtime() time travel? To: freebsd-hackers@freebsd.org Date: Mon, 10 Nov 1997 18:46:45 -0500 (EST) From: David Petrou X-Mailer: ELM [version 2.4 PL25-40] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Hi. I'm seeing something quite bizarre with microtime() under certain circumstances. I've made a little hack so that whenever a process is going to be desceduled (in mi_switch()) i print to the console how many microseconds the process used since it was scheduled. Normally, this works just fine. I see the output of the printf() in my xconsole. Now, I also have a serial console attached to my machine. If I kill my xconsole, kernel printf()'s go to my serial console at a much slower rate of 9600 baud. When I do this, my printf()'s start reporting that the process is using _negative_ amounts of time. Any potential explanations? Thanks, David