Re: [PATCH 0/4] Rework alarm timer infrastrucure - take2

Avi Kivity
2007-08-19T19:31:26Z

Luca wrote:
> On 8/19/07, Luca Tettamanti <kronos.it-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
>> +static uint64_t qemu_next_deadline(void) {
>> + uint64_t nearest_delta_us = ULLONG_MAX;
>> + uint64_t vmdelta_us;
>>
>
> Hum, I introduced a bug here... those vars should be signed.
>
> On the overhead introduced: how do you measure it?
>
>

Run a 100Hz guest, measure cpu usage using something accurate like
cyclesoak, with and without dynticks, with and without kvm.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.