Re: [Xen-devel] [PATCH v3 02/11] hvm/hpet: Only call guest_time_hpet(h) one time per action.

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 17.04.14 at 19:42, <dslutz@xxxxxxxxxxx> wrote:
> v3:
>   Did not add Reviewed-by (Jan Beulich) do to amount of change
>   Added passing of guest_time to hpet_read64() and
>     hpet_stop_timer().

But that wasn't as a result of the review of v2, was it? Especially for
the hpet_read64() case I fear this is going a little too far, since now
you call the supposedly expensive function even when the value isn't
needed. I suppose you could resolve this by passing a known-invalid
value to the function from hpet_read() (so it knows to call
guest_time_hpet() itself) and use the always-preset variant on from
hpet_write().

Otoh I admit that the only supposedly frequently use operations
ought to be the two ones needing the value, so perhaps the
overhead for the other ones is tolerable. Let's see whether others
have any opinion on this.

Apart from that I'm still fine with the patch.

Jan


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