pavel@NetBSD.org wrote:

> I notice it periodically synces the local cycle counters.  Is it really
> needed? I think Alpha motherboard have a central clock which drives the
> CPUs, so they are always precisely syncronized and this shouldn't be
> needed.

If each CPU has PLL to multiply base clock, each PLL has
an internal oscillator which is controlled by comparing against
base clock with feedback loop. They are almost syncronized but
not precisely, so could have a few tolerance, I think.

Anyway, current kern_microtime.c based code also has the similar
sync code in the clock interrupt. (see alpha/interrupt.c)
---
Izumi Tsutsui