# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	peda
# Host:	sectra.se
# Root:	D:/Projekt/NTP/bk/ntp-dev-perf

#
#--- 1.13/ports/winnt/ntpd/nt_clockstuff.c	Wed Apr 16 15:18:16 2003
#+++ 1.14/ports/winnt/ntpd/nt_clockstuff.c	Thu Oct 16 09:46:24 2003
#@@ -299,6 +299,179 @@
# 	return 0;
# }
# 
#+#define PERF_FILTER_SIZE (2048)
#+static LONGLONG perf_filter[PERF_FILTER_SIZE];
#+static int perf_oldest = -1;
#+static int perf_newest = -1;
#+static int perf_full = 0;
#+static LONGLONG perf_sum = 0;
#+static LONGLONG perf_offset = 0;
#+static LONGLONG perf_offset_index = -1;
#+static LONGLONG perf_offset_backup = 0;
#+static LONGLONG perf_offset_backup_index = -1;
#+static LONGLONG perf_count;
#+
#+static void
#+perf_reset(LONGLONG perf_count_now)
#+{
#+	perf_oldest = -1;
#+	perf_newest = 0;
#+	perf_full = 0;
#+	perf_count = perf_count_now;
#+	perf_sum = 0;
#+	perf_offset_index = perf_newest;
#+	perf_offset = 0;
#+	perf_offset_backup_index = -1;
#+}
#+
#+static void
#+perf_inc(int *perf_index)
#+{
#+	*perf_index = (*perf_index + 1) % PERF_FILTER_SIZE;
#+}
#+
#+static LONGLONG
#+perf_insert(LONGLONG diff)
#+{
#+	LONGLONG sum;
#+	LONGLONG prev_sum = perf_sum;
#+
#+	perf_inc(&perf_newest);
#+	if (perf_newest == perf_oldest) {
#+		perf_sum -= perf_filter[perf_oldest];
#+		perf_inc(&perf_oldest);
#+		perf_full = 1;
#+	}
#+	perf_count += diff;
#+	perf_filter[perf_newest] = diff;
#+	perf_sum += diff;
#+
#+	if (!perf_full) {
#+		int count;
#+
#+		if (perf_oldest == -1) {
#+			/* first call to perf_insert */
#+			perf_oldest = perf_newest;
#+			return perf_count;
#+		}
#+
#+		count = (perf_newest - perf_oldest + PERF_FILTER_SIZE)
#+			% PERF_FILTER_SIZE + 1;
#+
#+		sum = (perf_sum * PERF_FILTER_SIZE + count / 2)
#+			/ count;
#+		prev_sum = (prev_sum * PERF_FILTER_SIZE + (count - 1) / 2)
#+			/ (count - 1);
#+
#+		if (count == 2)
#+			/* Init perf_offset so that it later becomes zero
#+			 * and that this sample therefore is used as a base.
#+			 */
#+			perf_offset = sum - diff * PERF_FILTER_SIZE;
#+	}
#+	else
#+		sum = perf_sum;
#+
#+	perf_offset += diff * PERF_FILTER_SIZE - sum;
#+
#+	if (perf_offset <= 0) {
#+		/* new base offset */
#+		perf_offset_index = perf_newest;
#+		perf_offset = 0;
#+		perf_offset_backup_index = -1;
#+	}
#+	else {
#+		if (perf_offset <= perf_offset_backup
#+			|| perf_offset_backup_index == -1) {
#+			/* new backup offset */
#+			perf_offset_backup_index = perf_newest;
#+			perf_offset_backup = perf_offset;
#+		}
#+
#+		if (perf_offset_index == perf_newest) {
#+			/* base offset disappeared, use backup */
#+			if (perf_offset_backup_index == -1) {
#+				/* Aiee! No backup, use this sample! */
#+				perf_offset_index = perf_newest;
#+				perf_offset = 0;
#+			}
#+			else {
#+				perf_offset_index = perf_offset_backup_index;
#+				perf_offset -= perf_offset_backup;
#+				perf_offset_backup_index = -1;
#+			}
#+		}
#+	}
#+
#+	return perf_count - perf_offset / PERF_FILTER_SIZE;
#+}
#+
#+static void
#+performance_filter(LARGE_INTEGER *perf_count_now, ULONGLONG TimerTime)
#+{
#+	LONGLONG time_diff;
#+	LONGLONG perf_diff;
#+	LONGLONG perf_diff_per_tick;
#+	int i, ticks;
#+	int diff_limit;
#+
#+	if (!every)
#+		return;
#+
#+	if (perf_newest == -1) {
#+		/* This is the 1st call */
#+		perf_reset(perf_count_now->QuadPart);
#+		return;
#+	}
#+
#+	/* Estimate how many ticks there has been
#+	 * since the last call
#+	 */
#+	time_diff = TimerTime - LastTimerTime;
#+	ticks = 0;
#+	while (time_diff > every / 2) {
#+		++ticks;
#+		time_diff -= every;
#+		if (ticks > 200) {
#+			/* Too many ticks: clock stepped forward?
#+			 * reset filter.
#+			 */
#+			msyslog(LOG_NOTICE,
#+				"missed too many ticks (> 200), "
#+				"diff %I64d, filter reset",
#+				TimerTime - LastTimerTime);
#+			perf_reset(perf_count_now->QuadPart);
#+			return;
#+		}
#+	}
#+
#+	diff_limit = every / 10;
#+	if (!ticks || time_diff > diff_limit || time_diff < -diff_limit) {
#+		/* No ticks: clock stepped back?
#+		 * Large drift: clock stepped forward?
#+		 * reset filter
#+		 */
#+		msyslog(LOG_NOTICE,
#+			"%d ticks, diff %I64d, filter reset",
#+			ticks, time_diff);
#+		perf_reset(perf_count_now->QuadPart);
#+		return;
#+	}
#+
#+	/* Split up the performance counter difference
#+	 * between these ticks
#+	 */
#+	perf_diff = perf_count_now->QuadPart - perf_count;
#+	perf_diff_per_tick = perf_diff / ticks;
#+
#+	i = ticks;
#+	while (--i > 0)
#+		perf_insert(perf_diff_per_tick);
#+
#+	perf_count_now->QuadPart
#+		= perf_insert(perf_diff - perf_diff_per_tick * (ticks - 1));
#+}
#+
# static void CALLBACK
# TimerApcFunction(
# 	LPVOID lpArgToCompletionRoutine,
#@@ -307,6 +480,7 @@
# 	)
# {
# 	LARGE_INTEGER LargeIntNowCount;
#+	ULONGLONG TimerTime;
# 	(void) lpArgToCompletionRoutine; /* not used */
# 
# 	if (dwTimerLowValue == lastLowTimer) return;
#@@ -317,6 +491,10 @@
# 	/* Save this for next time */
# 	lastLowTimer = dwTimerLowValue;
# 
#+	TimerTime = ((ULONGLONG) dwTimerHighValue << 32) +
#+				(ULONGLONG) dwTimerLowValue;
#+	performance_filter(&LargeIntNowCount, TimerTime);
#+
# 	/* Check to see if the counter has rolled. This happens
# 	   more often on Multi-CPU systems */
# 
#@@ -339,8 +517,7 @@
# 		
# 	EnterCriticalSection(&TimerCritialSection);
# 	LastTimerCount = (ULONGLONG) LargeIntNowCount.QuadPart;
#-	LastTimerTime = ((ULONGLONG) dwTimerHighValue << 32) +
#-				(ULONGLONG) dwTimerLowValue;
#+	LastTimerTime = TimerTime;
# 	LeaveCriticalSection(&TimerCritialSection);
# }
# 
#

# Diff checksum=ac9647d6


# Patch vers:	1.3
# Patch type:	REGULAR

== ChangeSet ==
stenn@whimsy.udel.edu|ChangeSet|19990526004811|57482|8983e65c737bb465
stenn@whimsy.udel.edu|ChangeSet|20031015095142|19094
D 1.1162 03/10/16 09:46:33+02:00 peda@sectra.se +1 -0
B stenn@whimsy.udel.edu|ChangeSet|19990526004811|57482|8983e65c737bb465
C
c A thread runs with high priority and detects when a tick has occured,
c when it has, the thread takes a sample from the performance counter.
c The performance counter sample is then used to extrapolate the system
c time between ticks.
c 
c The problem is that the thread only samples once every millisecond (on
c the best of days, on a loaded system it can be more seldom) so there is
c typically 1 ms jitter just because of this.
c 
c This patch filters out the best sample in the recent past and uses that
c sample as the base, until a better sample comes along, or the sample
c grows too old (currently 20 seconds).
c 
c When my system is quiet, I get accuracies around 10 microseconds,
c but when the usage pattern of the computer changes, the offset can
c temporarily grow to 50 us.
K 18162
P ChangeSet
------------------------------------------------

0a0
> stenn@whimsy.udel.edu|ports/winnt/ntpd/nt_clockstuff.c|19991016040804|07763|8b711e53 peda@sectra.se|ports/winnt/ntpd/nt_clockstuff.c|20031016074624|17871

== ports/winnt/ntpd/nt_clockstuff.c ==
stenn@whimsy.udel.edu|ports/winnt/ntpd/nt_clockstuff.c|19991016040804|07763|8b711e53
mayer@tecotoo.myibg.com|ports/winnt/ntpd/nt_clockstuff.c|20030416131816|23470
D 1.14 03/10/16 09:46:24+02:00 peda@sectra.se +179 -2
B stenn@whimsy.udel.edu|ChangeSet|19990526004811|57482|8983e65c737bb465
C
c A thread runs with high priority and detects when a tick has occured,
c when it has, the thread takes a sample from the performance counter.
c The performance counter sample is then used to extrapolate the system
c time between ticks.
c 
c The problem is that the thread only samples once every millisecond (on
c the best of days, on a loaded system it can be more seldom) so there is
c typically 1 ms jitter just because of this.
c 
c This patch filters out the best sample in the recent past and uses that
c sample as the base, until a better sample comes along, or the sample
c grows too old (currently 20 seconds).
c 
c When my system is quiet, I get accuracies around 10 microseconds,
c but when the usage pattern of the computer changes, the offset can
c temporarily grow to 50 us.
K 17871
O -rw-rw-r--
P ports/winnt/ntpd/nt_clockstuff.c
------------------------------------------------

I301 173
#define PERF_FILTER_SIZE (2048)
static LONGLONG perf_filter[PERF_FILTER_SIZE];
static int perf_oldest = -1;
static int perf_newest = -1;
static int perf_full = 0;
static LONGLONG perf_sum = 0;
static LONGLONG perf_offset = 0;
static LONGLONG perf_offset_index = -1;
static LONGLONG perf_offset_backup = 0;
static LONGLONG perf_offset_backup_index = -1;
static LONGLONG perf_count;
\
static void
perf_reset(LONGLONG perf_count_now)
{
	perf_oldest = -1;
	perf_newest = 0;
	perf_full = 0;
	perf_count = perf_count_now;
	perf_sum = 0;
	perf_offset_index = perf_newest;
	perf_offset = 0;
	perf_offset_backup_index = -1;
}
\
static void
perf_inc(int *perf_index)
{
	*perf_index = (*perf_index + 1) % PERF_FILTER_SIZE;
}
\
static LONGLONG
perf_insert(LONGLONG diff)
{
	LONGLONG sum;
	LONGLONG prev_sum = perf_sum;
\
	perf_inc(&perf_newest);
	if (perf_newest == perf_oldest) {
		perf_sum -= perf_filter[perf_oldest];
		perf_inc(&perf_oldest);
		perf_full = 1;
	}
	perf_count += diff;
	perf_filter[perf_newest] = diff;
	perf_sum += diff;
\
	if (!perf_full) {
		int count;
\
		if (perf_oldest == -1) {
			/* first call to perf_insert */
			perf_oldest = perf_newest;
			return perf_count;
		}
\
		count = (perf_newest - perf_oldest + PERF_FILTER_SIZE)
			% PERF_FILTER_SIZE + 1;
\
		sum = (perf_sum * PERF_FILTER_SIZE + count / 2)
			/ count;
		prev_sum = (prev_sum * PERF_FILTER_SIZE + (count - 1) / 2)
			/ (count - 1);
\
		if (count == 2)
			/* Init perf_offset so that it later becomes zero
			 * and that this sample therefore is used as a base.
			 */
			perf_offset = sum - diff * PERF_FILTER_SIZE;
	}
	else
		sum = perf_sum;
\
	perf_offset += diff * PERF_FILTER_SIZE - sum;
\
	if (perf_offset <= 0) {
		/* new base offset */
		perf_offset_index = perf_newest;
		perf_offset = 0;
		perf_offset_backup_index = -1;
	}
	else {
		if (perf_offset <= perf_offset_backup
			|| perf_offset_backup_index == -1) {
			/* new backup offset */
			perf_offset_backup_index = perf_newest;
			perf_offset_backup = perf_offset;
		}
\
		if (perf_offset_index == perf_newest) {
			/* base offset disappeared, use backup */
			if (perf_offset_backup_index == -1) {
				/* Aiee! No backup, use this sample! */
				perf_offset_index = perf_newest;
				perf_offset = 0;
			}
			else {
				perf_offset_index = perf_offset_backup_index;
				perf_offset -= perf_offset_backup;
				perf_offset_backup_index = -1;
			}
		}
	}
\
	return perf_count - perf_offset / PERF_FILTER_SIZE;
}
\
static void
performance_filter(LARGE_INTEGER *perf_count_now, ULONGLONG TimerTime)
{
	LONGLONG time_diff;
	LONGLONG perf_diff;
	LONGLONG perf_diff_per_tick;
	int i, ticks;
	int diff_limit;
\
	if (!every)
		return;
\
	if (perf_newest == -1) {
		/* This is the 1st call */
		perf_reset(perf_count_now->QuadPart);
		return;
	}
\
	/* Estimate how many ticks there has been
	 * since the last call
	 */
	time_diff = TimerTime - LastTimerTime;
	ticks = 0;
	while (time_diff > every / 2) {
		++ticks;
		time_diff -= every;
		if (ticks > 200) {
			/* Too many ticks: clock stepped forward?
			 * reset filter.
			 */
			msyslog(LOG_NOTICE,
				"missed too many ticks (> 200), "
				"diff %I64d, filter reset",
				TimerTime - LastTimerTime);
			perf_reset(perf_count_now->QuadPart);
			return;
		}
	}
\
	diff_limit = every / 10;
	if (!ticks || time_diff > diff_limit || time_diff < -diff_limit) {
		/* No ticks: clock stepped back?
		 * Large drift: clock stepped forward?
		 * reset filter
		 */
		msyslog(LOG_NOTICE,
			"%d ticks, diff %I64d, filter reset",
			ticks, time_diff);
		perf_reset(perf_count_now->QuadPart);
		return;
	}
\
	/* Split up the performance counter difference
	 * between these ticks
	 */
	perf_diff = perf_count_now->QuadPart - perf_count;
	perf_diff_per_tick = perf_diff / ticks;
\
	i = ticks;
	while (--i > 0)
		perf_insert(perf_diff_per_tick);
\
	perf_count_now->QuadPart
		= perf_insert(perf_diff - perf_diff_per_tick * (ticks - 1));
}
\
I309 1
	ULONGLONG TimerTime;
I319 4
	TimerTime = ((ULONGLONG) dwTimerHighValue << 32) +
				(ULONGLONG) dwTimerLowValue;
	performance_filter(&LargeIntNowCount, TimerTime);
\
D342 2
I343 1
	LastTimerTime = TimerTime;

# Patch checksum=75e4622a