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Allow all powers of 2 from 2^0 to 2^16 for hz.
Enable hz==1200.
This commit is contained in:
mycroft 2000-05-29 15:05:10 +00:00
parent 8dcf08ff77
commit 7513b8e18d
1 changed files with 42 additions and 4 deletions
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46
sys/kern/kern_clock.c
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@ -1,4 +1,4 @@
/* $NetBSD: kern_clock.c,v 1.56 2000/05/29 14:58:59 mycroft Exp $ */
/* $NetBSD: kern_clock.c,v 1.57 2000/05/29 15:05:10 mycroft Exp $ */
/*-
* Copyright (c) 2000 The NetBSD Foundation, Inc.
@ -398,6 +398,24 @@ initclocks()
#ifdef NTP
switch (hz) {
case 1:
shifthz = SHIFT_SCALE - 0;
break;
case 2:
shifthz = SHIFT_SCALE - 1;
break;
case 4:
shifthz = SHIFT_SCALE - 2;
break;
case 8:
shifthz = SHIFT_SCALE - 3;
break;
case 16:
shifthz = SHIFT_SCALE - 4;
break;
case 32:
shifthz = SHIFT_SCALE - 5;
break;
case 60:
case 64:
shifthz = SHIFT_SCALE - 6;
@ -417,6 +435,25 @@ initclocks()
case 1024:
shifthz = SHIFT_SCALE - 10;
break;
case 1200:
case 2048:
shifthz = SHIFT_SCALE - 11;
break;
case 4096:
shifthz = SHIFT_SCALE - 12;
break;
case 8192:
shifthz = SHIFT_SCALE - 13;
break;
case 16384:
shifthz = SHIFT_SCALE - 14;
break;
case 32768:
shifthz = SHIFT_SCALE - 15;
break;
case 65536:
shifthz = SHIFT_SCALE - 16;
break;
default:
panic("weird hz");
}
@ -677,13 +714,14 @@ hardclock(frame)
* obase=2
* idealhz/realhz
* where `idealhz' is the next higher power of 2, and `realhz'
* is the actual value.
* is the actual value. You may need to factor this result
* into a sequence of 2 multipliers to get better precision.
*
* Likewise, the error can be calculated with (e.g. for 100Hz):
* bc -q
* scale=24
* ((1+2^-2+2^-5)*realhz-idealhz)/idealhz
* (and then multiply by 100 to get %).
* ((1+2^-2+2^-5)*(1-2^-10)*realhz-idealhz)/idealhz
* (and then multiply by 1000000 to get ppm).
*/
switch (hz) {
case 96: