Il 27/03/2012 17:08, Jan Kiszka ha scritto:
>>> +#if defined(__sun__)
>>> + if (timer_create(CLOCK_HIGHRES, &ev, &host_timer)) {
>>> +#else
>>> if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
>>> +#endif
>>
>> This should be #ifdef CLOCK_HIGHRES.
>
> Are we sure about this is and will remain equivalent and correct?
>
> Also, I found some man page that says CLOCK_HIGHRES is non-adjustable
> while CLOCK_REALTIME is. That should make a difference in QEMU.
Right, that's why I CCed you but then I forgot to ask the question.
Does QEMU rely on CLOCK_REALTIME when "-rtc clock=host" is in use? A
monotonic clock would work better when CLOCK_REALTIME jumps backwards
(DST->solar). If the jump goes unnoticed, the alarm timer would have no
timeout for an hour or so.
Of course the opposite is true when going from solar time to DST; you
move the realtime clock one hour forward and, with CLOCK_MONOTONIC, a
host_clock timer to trigger an hour too late.
Paolo
