Received: from PACIFIC-CARRIER-ANNEX.MIT.EDU by po7.MIT.EDU (5.61/4.7) id AA28100; Wed, 20 Dec 95 02:00:25 EST Received: from pain.lcs.mit.edu by MIT.EDU with SMTP id AA23138; Wed, 20 Dec 95 02:00:26 EST Received: (from daemon@localhost) by pain.lcs.mit.edu (8.6.12/8.6.9) id AAA16421; Wed, 20 Dec 1995 00:12:06 -0500 Received: from BALVENIE.PDL.CS.CMU.EDU by pain.lcs.mit.edu (8.6.12/8.6.9) with SMTP id AAA16384 for ; Wed, 20 Dec 1995 00:05:13 -0500 Received: from localhost by BALVENIE.PDL.CS.CMU.EDU id aa28827; 20 Dec 95 0:04 EST To: netbsd-developers@netbsd.org Cc: cgd@BALVENIE.PDL.CS.CMU.EDU X-Copyright: Copyright 1995, Christopher G. Demetriou. All rights reserved. X-Notice: Duplication and redistribution prohibited without consent of the author. Subject: interface to put MD hooks into 'hardclock'? Date: Wed, 20 Dec 1995 00:04:41 -0500 Message-Id: <29373.819435881@BALVENIE.PDL.CS.CMU.EDU> From: Chris G Demetriou Sender: owner-netbsd-developers@NetBSD.ORG Precedence: first-class X-Loop: netbsd-developers@NetBSD.ORG hi folks... I'm wondering if anybody has any good ideas for ways to put machine-dependent hooks into hardclock()... In particular, what i need is something so that i can say: Index: kern_clock.c =================================================================== RCS file: /usr/users/cgd/NetBSD/cvs/src/sys/kern/kern_clock.c,v retrieving revision 1.3 diff -u -r1.3 kern_clock.c --- 1.3 1995/03/06 17:27:17 +++ kern_clock.c 1995/12/20 02:25:50 @@ -203,8 +203,10 @@ if (tickfixcnt > tickfixinterval) { delta += tickfix; tickfixcnt = 0; + reset_cc_offset(); } - } + } else + reset_cc_offset(); if (timedelta != 0) { delta = tick + tickdelta; timedelta -= tickdelta; that is, if tickfix == 0, then run that function every time a tick happens, otherwise run it when a tick causes tickfix to be applied... i've converted the Alpha to use the Process Cycle Counter when doing microtime(), and want to sync a cycle count 'base' with the clock every time the clock and the cycle counter should theoretically match. (that happens to be every time a tickfix is applied, if tickfix != 0, or at every clock tick.) I'm also vaguely interested in adding something to hardclock so that it'll accumulate a clock tick into an interrupt counter, so that i don't have to jump through another function when going to hardclock... any ideas on how to do this reasonably? I'd rather not #ifdef alpha, because at least some of these hooks could potentially be useful on other ports. (the pmax has a TC cycle counter that can be used for timing, apparently, and pentiums have cycle counters ... i dunno about anything else.) it's nice to get ~10us resolution in userland via gettimeofday()... 8-) chris