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49a116737e
freebsd-nq/sys
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Bruce Evans 49a116737e Estimate an initial overhead of 0 usec instead of 20 usec in DELAY(). 
I have code to calibrate the overhead fairly accurately, but there
is little point in using it since it is most accurate on machines
where an estimate of 0 works well.  On slow machines, the accuracy
of DELAY() has a large variance since it is limited by the resolution
of getit() even if the initial delay is calibrated perfectly.

Use fixed point and long longs to speed up scaling in DELAY().
The old method slowed down a lot when the frequency became variable.
Assume the default frequency for short delays so that the fixed
point calculation can be exact.

Fast scaling is only important for small delays.  Scaling is done
after looking at the counter and outside the loop, so it doesn't
decrease accuracy or resolution provided it completes before the
delay is up.  The comment in the code is still confused about this.
1997-01-29 22:51:44 +00:00
..
alpha Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
amd64 Estimate an initial overhead of 0 usec instead of 20 usec in DELAY(). 1997-01-29 22:51:44 +00:00
compat/linux Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
compile Stop cvs up -P from removing empty compile directories. 1994-08-25 16:20:16 +00:00
conf Synchronize with sys/i386/conf/options.i386 revision 1.34. 1997-01-28 13:10:22 +00:00
ddb Fixed printing of small offsets. E.g., -4(%ebp) is now printed 1997-01-16 11:27:11 +00:00
dev Fixes and workarounds for Hayes ESP: 1997-01-29 21:50:02 +00:00
fs Change the map entry flags from bitfields to bitmasks. Allows 1997-01-16 04:16:22 +00:00
geom Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
gnu Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
i386 Estimate an initial overhead of 0 usec instead of 20 usec in DELAY(). 1997-01-29 22:51:44 +00:00
isa Estimate an initial overhead of 0 usec instead of 20 usec in DELAY(). 1997-01-29 22:51:44 +00:00
isofs/cd9660 Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
kern Fixed EXTRAVNODES ifdef. 1997-01-27 12:48:15 +00:00
libkern Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
miscfs Change the map entry flags from bitfields to bitmasks. Allows 1997-01-16 04:16:22 +00:00
modules Upgrade the kbdio rutines to provide queued kbd & mouse events. 1997-01-15 18:16:32 +00:00
msdosfs Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
net fix mixleading comment (my error.. I wrote the comment) 1997-01-26 01:00:45 +00:00
netatalk Convert the interface address and IP interface address structures 1996-12-13 21:29:07 +00:00
netinet Count multicast packets received for groups of which we are not 1997-01-21 21:08:09 +00:00
netipx Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
netkey This is the `netkey' kernel key-management service (the PF_KEY analogue 1996-06-14 17:22:18 +00:00
netns Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
nfs Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
nfsclient Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
nfsserver Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
pc98 Fixed reset port address of PC-9801-108. 1997-01-29 12:42:41 +00:00
pccard One other minor include file change. 1997-01-14 16:29:05 +00:00
pci Add 1997 to my copyright. 1997-01-29 05:28:21 +00:00
powerpc/include Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
rpc Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
scsi Removed `Debugger("no slices")'. It's normal and harmless to have no 1997-01-29 14:18:34 +00:00
sys Removed #undef of MSGMAX, so that a warning gets printed if it is 1997-01-27 11:18:27 +00:00
tools Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
ufs Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00
vm Added a check/panic for v_usecount being 0 (no vnode reference) in 1997-01-24 22:20:23 +00:00
Makefile Make the long-awaited change from $Id$ to $FreeBSD$ 1997-01-14 07:20:47 +00:00