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Re: microtime(9) on QEMU

On Sat, Oct 31, 2009 at 06:53:11PM -0500, David Young wrote:
> The microtime(9) manual page sets my expectation that microtime(9) is
> monotonically non-decreasing.  Is QEMU just broken?  Are there any
> conditions (such as elevated IPL) where I should expect for the "seconds
> hand" to stop, but the "microseconds hand" to keep "rotating"?

The only situation in which microtime(9) should ever be non-monotonic is
when faced with very long times of very high IPL. E.g. it is not always
possible and handle a time counter wrap around. So as long as the 
timer interrupt runs often enough, it should not be an issue and
everything else is a bug.


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