From owner-freebsd-alpha  Tue May  1  8:18:30 2001
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From: Andrew Gallatin <gallatin@cs.duke.edu>
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Date: Tue, 1 May 2001 11:17:54 -0400 (EDT)
To: Rolf Neugebauer <neugebar@dcs.gla.ac.uk>
Cc: freebsd-alpha@FreeBSD.ORG
Subject: Re: determine cycle counter frequency in user space
In-Reply-To: <ysqpudt9yus.fsf@therese.dcs.gla.ac.uk>
References: <200104302147.OAA12404@usr01.primenet.com>
	<ysqpudt9yus.fsf@therese.dcs.gla.ac.uk>
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Rolf Neugebauer writes:
 > 
 > However, to get an estimate for cycles per second, I was looking for a
 > programmatic way to access above mentioned variables instead of
 > providing them as command line arguments. I'll just add an appropriate
 > sysctl to get cycles_per_sec. If people are interested, I'll submit a
 > patch.

Depending on how accurate you needed them to be, you might be able to
just calculate them.

__inline int
GetClockCycleFreq(void)
{
	unsigned long t0, t1;
	int delta_t = -1;

	do {
		/* loop to avoid nasty negative cycle counts.. */
		t0 = alpha_rpcc();
		sleep(1);
		t1 = alpha_rpcc();
		delta_t = t1 - t0;
	} while (delta_t < 0);
	return(delta_t);
}

Drew

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