Perry E. Metzger wrote:
> We can check the cycle timer, but the problem there is that we can
> easily lose on a machine with a variable rate clock.

True, but we might use aproximation like this:

1. In hardclock(9), remember rdtsc value (to, say 'hardclock_rdtsc')
2. change microtime(9) to compute the time like:

	struct timeval tv;

	int s = splclock();
	tv = mono_time;
	splx(s);

	tv.tv_usec += (current_rdtsc - hardclock_rdtsc) * curr_proc_clock_rate;

	iv (tv.tv_usec > 1000000) {
		tv.tv_sec++;
		tv.tv_usec -= 1000000;
	}

This should be much faster. This should be as accurate as current
method on fixed-clock-rate processors, and since the base ('mono_time')
is updated each 1/100 s on i386, the difference in accuracy of time
on variable rate processors should be negliable too.

Jaromir
-- 
Jaromir Dolecek <jdolecek@NetBSD.org> http://www.NetBSD.org/Ports/i386/ps2.html
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