No longer use the cyclecounter to attempt to correct for late or missed

clock interrupts.

Keep a 1-in-16 smoothed average of the length of each tick.  If the
CPU speed is correctly diagnosed, this should give experienced users
enough information to figure out a more suitable value for `tick'.
This commit is contained in:
Garrett Wollman 1996-01-30 18:56:47 +00:00
parent dbd7e3e1cb
commit 3addba4f55
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=13758
7 changed files with 22 additions and 17 deletions

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@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.49 1996/01/15 21:26:43 phk Exp $
* $Id: clock.c,v 1.50 1996/01/16 06:35:40 ache Exp $
*/
/*
@ -99,6 +99,7 @@ u_int idelayed;
unsigned i586_ctr_rate;
long long i586_ctr_bias;
long long i586_last_tick;
unsigned long i586_avg_tick;
#endif
u_int stat_imask = SWI_CLOCK_MASK;
int timer0_max_count;

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@ -3,7 +3,7 @@
* Garrett Wollman, September 1994.
* This file is in the public domain.
*
* $Id: clock.h,v 1.7 1995/12/10 13:38:07 phk Exp $
* $Id: clock.h,v 1.8 1995/12/24 08:10:49 davidg Exp $
*/
#ifndef _MACHINE_CLOCK_H_
@ -58,6 +58,7 @@ extern int disable_rtc_set;
extern unsigned i586_ctr_rate; /* fixed point */
extern long long i586_last_tick;
extern long long i586_ctr_bias;
extern unsigned long i586_avg_tick;
#endif
extern int timer0_max_count;
extern u_int timer0_overflow_threshold;
@ -72,17 +73,16 @@ static __inline u_long
cpu_thisticklen(u_long dflt)
{
long long old;
long rv;
long len;
if (i586_ctr_rate) {
old = i586_last_tick;
I586_CYCLECTR(i586_last_tick);
rv = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
len = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
/ i586_ctr_rate;
} else {
rv = dflt;
i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16;
}
return rv;
return dflt;
}
#endif

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@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.49 1996/01/15 21:26:43 phk Exp $
* $Id: clock.c,v 1.50 1996/01/16 06:35:40 ache Exp $
*/
/*
@ -99,6 +99,7 @@ u_int idelayed;
unsigned i586_ctr_rate;
long long i586_ctr_bias;
long long i586_last_tick;
unsigned long i586_avg_tick;
#endif
u_int stat_imask = SWI_CLOCK_MASK;
int timer0_max_count;

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.49 1996/01/15 21:26:43 phk Exp $
* $Id: clock.c,v 1.50 1996/01/16 06:35:40 ache Exp $
*/
/*
@ -99,6 +99,7 @@ u_int idelayed;
unsigned i586_ctr_rate;
long long i586_ctr_bias;
long long i586_last_tick;
unsigned long i586_avg_tick;
#endif
u_int stat_imask = SWI_CLOCK_MASK;
int timer0_max_count;

View File

@ -3,7 +3,7 @@
* Garrett Wollman, September 1994.
* This file is in the public domain.
*
* $Id: clock.h,v 1.7 1995/12/10 13:38:07 phk Exp $
* $Id: clock.h,v 1.8 1995/12/24 08:10:49 davidg Exp $
*/
#ifndef _MACHINE_CLOCK_H_
@ -58,6 +58,7 @@ extern int disable_rtc_set;
extern unsigned i586_ctr_rate; /* fixed point */
extern long long i586_last_tick;
extern long long i586_ctr_bias;
extern unsigned long i586_avg_tick;
#endif
extern int timer0_max_count;
extern u_int timer0_overflow_threshold;
@ -72,17 +73,16 @@ static __inline u_long
cpu_thisticklen(u_long dflt)
{
long long old;
long rv;
long len;
if (i586_ctr_rate) {
old = i586_last_tick;
I586_CYCLECTR(i586_last_tick);
rv = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
len = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
/ i586_ctr_rate;
} else {
rv = dflt;
i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16;
}
return rv;
return dflt;
}
#endif

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@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.49 1996/01/15 21:26:43 phk Exp $
* $Id: clock.c,v 1.50 1996/01/16 06:35:40 ache Exp $
*/
/*
@ -99,6 +99,7 @@ u_int idelayed;
unsigned i586_ctr_rate;
long long i586_ctr_bias;
long long i586_last_tick;
unsigned long i586_avg_tick;
#endif
u_int stat_imask = SWI_CLOCK_MASK;
int timer0_max_count;

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.49 1996/01/15 21:26:43 phk Exp $
* $Id: clock.c,v 1.50 1996/01/16 06:35:40 ache Exp $
*/
/*
@ -99,6 +99,7 @@ u_int idelayed;
unsigned i586_ctr_rate;
long long i586_ctr_bias;
long long i586_last_tick;
unsigned long i586_avg_tick;
#endif
u_int stat_imask = SWI_CLOCK_MASK;
int timer0_max_count;