Messages in this thread |  | | | Date | Thu, 3 Apr 2008 08:28:25 +0200 (CEST) | | From | Thomas Gleixner <> | | Subject | Re: gettimeofday() jumping into the future | |
On Thu, 3 Apr 2008, Karsten Wiese wrote:
> > To prevent this TSC specific wreckage we need to compare the TSC value
> > against the reference value and return the latter when it is larger
> > than the actual TSC value.
>
> Last paragraph IMO should be:
> To prevent this TSC specific wreckage we need to substract the
> reference value from the TSC value, interpret the result as
> signed. If the interpreted result is negative, return the reference
> value, else the TSC Value.
> Your patch misses the corner case where TSC value is < reference _and_ valid
> at TSC wrap around.
In about 200 years on a 3Ghz box.
> The access to the reference value needs a (the xtime ?) lock on 32bit, no?
The readout is under xtime lock anyway.
Thanks,
tglx
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