Date: Fri, 28 May 1999 07:09:01 -0700 (PDT) From: Bruce Evans <bde@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/isa apic_vector.s clock.c icu_vector.s Message-ID: <199905281409.HAA31124@freefall.freebsd.org>
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bde 1999/05/28 07:09:01 PDT
Modified files:
sys/i386/isa apic_vector.s clock.c icu_vector.s
Log:
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
Revision Changes Path
1.38 +32 -27 src/sys/i386/isa/apic_vector.s
1.134 +21 -20 src/sys/i386/isa/clock.c
1.12 +20 -18 src/sys/i386/isa/icu_vector.s
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