Re: adding functions for easy access to cycle counters

[Thor Lancelot Simon <tls%rek.tjls.com@localhost>]

On Thu, Mar 06, 2008 at 10:38:06AM -0500, Blair Sadewitz wrote:
> Hello,
> 
> Does anyone have an opinion on adding functions in
> src/common/lib/libc/atomic for reading CPU cycle counters?  I thought
> of this while working on a JACK audio package:  I've already converted
> it to use the atomic ops in userland.  If I had an MI function to read
> the cycle counter, e.g. rtdsc on x86, then it could build easily on
> any platform NetBSD-current supports.

I could use these to remove a number of very expensive gettimeofday()
calls in OpenSSL.  But how will they work on multiprocessors?

Thor