Timers and timing, was: MySQL Performance 6.0rc1

[Poul-Henning Kamp]

In message <436226AF.10109 at freebsd.org>, David Xu writes:

>That's just an idea. :-)
>As robert said, add a lower resolution CLOCK_ type  may work well.
>Another thing I just though of, if reading timercounter is so slow, won't
>gettimeofday hardly block cpu too many cycles ? the cpu is just stucked
>there by a slow clock in hardware signals.

The get*() family of functions just copy a timestamp, they go nowhere
near hardware.  So they are fast, but less precise (~ 1 msec).

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.