Re: timer is off in HVM FreeBSD

[fukumoto%imasy.or.jp@localhost]

Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
>> Not much, exept it's probably not a netbsd-related issue. The timers
>> are managed directly by the hypervisor, not by dom0.
>> Here it looks like the FreeBSD kernel has a wrong idea of what the
>> Xen tick interrupt rate is. It's not easy to get right, because it
>> may be called more often than it should, or less often depending on
>> the load of the system. NetBSD's sys/arch/xen/xen/clock.c (including
>> the CVS log because it took several tries to get it right) has good
>> hints about how it works


I don't know how it works, isn't it emulated by QEMU?  Shouldn't it be
sys/arch/x86/isa/clock.c (and on FreeBSD src/sys/i386/clock.c)?

Meanwhile I tried sysctl -w kern.timecounter.hardware=i8254 (or TSC)
in FreeBSD to see if anything changes from the default ACPI-safe, but
no difference as far as I can see.  Booting up FreeBSD in verbose mode
I see these messages:

Calibrating clock(s) ... i8254 clock: 513169 Hz
513169 Hz differs from default of 1193182 Hz by more than 1%
Timecounter "i8254" frequency 1193182 Hz quality 0
Calibrating TSC clock ... TSC clock: 2204623115 Hz


                                                FUKUMOTO Atsushi
                                                fukumoto%imasy.or.jp@localhost