From owner-freebsd-hackers Sat Apr 13 6:50:31 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from zibbi.icomtek.csir.co.za (zibbi.icomtek.csir.co.za [146.64.24.58]) by hub.freebsd.org (Postfix) with ESMTP id 68B4337B400; Sat, 13 Apr 2002 06:50:23 -0700 (PDT) Received: (from jhay@localhost) by zibbi.icomtek.csir.co.za (8.11.6/8.11.6) id g3DDoBn69302; Sat, 13 Apr 2002 15:50:11 +0200 (SAT) (envelope-from jhay) From: John Hay Message-Id: <200204131350.g3DDoBn69302@zibbi.icomtek.csir.co.za> Subject: microtime trustworthiness during booting? To: hackers@freebsd.org Date: Sat, 13 Apr 2002 15:50:10 +0200 (SAT) X-Mailer: ELM [version 2.4ME+ PL54 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hi, From what stage during the boot process can I trust that microtime() will give me incrementing time? The reason I ask is that I see microtime() jump backwards consistently during the ich_calibrate() function in the ich sound driver. The values look basically the same every time. Something like this: t1 2 sec 389291 usec t2 0 sec 32061 usec The interesting thing is that on another identical machine it doesn't happen and the calibrate routine works correctly. The only difference is that that machine use a GENERIC kernel and mine have a kernel with apm removed so that I can use the TSC as timecounter. Can it be that there is some kind of glitch somewhere when the TSC take over as timecounter? John -- John Hay -- John.Hay@icomtek.csir.co.za / jhay@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message