Messages in this thread | | | Date | Tue, 17 Mar 2009 19:12:16 +0900 | From | Yasunori Goto <> | Subject | Re: [Patch] Fix the possibility of insane return value of hpet_calibrate() against SMI. |
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Sorry for late response.
> Yasunori Goto wrote: > > > I've no sense of feel for how long each calibration run would take. > > > Would doing it 5 times show up as a significant increase in the boot > > > time for those that care about boot time being as quick as possible? > > > > Hmm. The loop times is trade off against reliable value.... > > Though SMI is rare interruption, I don't know how frequent > > hypervisor's switch is. > > Could you, just for testing, run the calibration five thousand times or > so instead of five times, and count how often you get insane values? > (And how much delay does such an SMI add?)
I tried 50000 times. But insane value was nothing. I think SMI is very rare.
> > Each calibration of this has 1 milli second. > > Do you think 5 msec is too long? > > This shouldn't matter when booting. Anyway, I think it's possible to > increase TICK_CALIBRATE without losing too much accuracy.
Hmm. If the person who is trying to reduce boot time for fastboot dislikes this impact, then I'll try Vojtech-san's way.
Thanks. -- Yasunori Goto
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