Re: xen/clock.c:get_tsc_offset_ns

[Jed Davis <jdev%panix.com@localhost>]

Jed Davis <jdev%panix.com@localhost> writes:

> I notice that the static function get_tsc_offset_ns in xen/clock.c
> multiplies a uint32_t by 1000000000, which looks to me as though it'll
> pretty much always overflow (if more than 4 cycles have passed since
> the last call to get_time_values_from_xen, it seems).  So, two questions:
>
> 1) Should that be 1000000000ULL instead? 

Now that I've looked at this a little more closely, change that to:
Why is that a uint32, and why is cpu_counter32() being called?
shadow_tsc_stamp is 64-bit.

> 2) If so, how much is this breaking?

The answer may be "quite a lot", if the shared_info time stuff is
updated as infrequently as it sounds like.  Also:

3) Hasn't this been discussed here before?

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