freebsd-nq/sys/amd64
Bruce Evans b50641ef9c Fixed glitches (jumps) of about 1/HZ seconds for the i8254 timecounter.
The old version only worked right when the time was read strictly
more often than every 1/HZ seconds, but we only guarantee reading
it every (1/HZ + epsilon) seconds.  Part of rev.1.126-1.127 attempted
to fix this but didn't succeed.  Detect counter rollover using the
heuristic from the old version of microtime() with additional
complications for supporting calls from fast interrupt handlers.
This works provided i8254 interrupts are not delayed by more than
1/(2*HZ) seconds.

This needs more comments, and cleanups for the SMP case, and more
testing of the SMP case before it is merged into RELENG_3.

Tested by:		jhay
1999-05-28 14:08:59 +00:00
..
amd64 Fixed glitches (jumps) of about 1/HZ seconds for the i8254 timecounter. 1999-05-28 14:08:59 +00:00
conf This commit adds driver support for PCI fast ethernet cards based on the 1999-05-21 04:37:48 +00:00
include Unbreak VESA on SMP. 1999-05-12 21:39:07 +00:00
isa Fixed glitches (jumps) of about 1/HZ seconds for the i8254 timecounter. 1999-05-28 14:08:59 +00:00
pci Move pcibus (host -> pci bus) probe/attach routines from nexus 1999-05-18 20:48:43 +00:00
Makefile Update to know about current kernel directory layout. 1999-02-28 22:14:16 +00:00