From owner-freebsd-current Wed Dec 18 12:07:58 1996 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id MAA24462 for current-outgoing; Wed, 18 Dec 1996 12:07:58 -0800 (PST) Received: from halloran-eldar.lcs.mit.edu (halloran-eldar.lcs.mit.edu [18.26.0.159]) by freefall.freebsd.org (8.8.4/8.8.4) with SMTP id MAA24457 for ; Wed, 18 Dec 1996 12:07:56 -0800 (PST) Received: by halloran-eldar.lcs.mit.edu; (5.65v3.2/1.1.8.2/19Aug95-0530PM) id AA08255; Wed, 18 Dec 1996 15:07:47 -0500 Date: Wed, 18 Dec 1996 15:07:47 -0500 From: Garrett Wollman Message-Id: <9612182007.AA08255@halloran-eldar.lcs.mit.edu> To: Laurent Joncheray Cc: current@freebsd.org Subject: microtime() resolution? In-Reply-To: <199612181933.OAA13797@obelix.aa.ans.net> References: <199612181933.OAA13797@obelix.aa.ans.net> Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk < said: > function, called from the IP driver? I mean, it is supposed to return > the time in us, but is the timer updated every us, or more often, or less? The timer is updated `hz' times a second (i.e., every 10 msec). However, microtime() uses a hardware register to interpolate between clock ticks with potentially-sub-microsecond resolution. -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, ANA, or NSA| - Susan Aglukark and Chad Irschick