Re: microtime(9) on QEMU

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Sun, Nov 01, 2009 at 12:58:27AM +0100, Joerg Sonnenberger wrote:
> 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.

Make that microuptime as microtime itself is of course effected by
settimeofday and related interfaces.

Joerg