Date: Thu, 15 Jan 2009 18:18:59 +0100 From: Mister Olli <mister.olli@googlemail.com> To: Freminlins <freminlins@gmail.com> Cc: freebsd-xen@freebsd.org, freebsd-questions@freebsd.org Subject: Re: sysctl machdep.independent_wallclock Message-ID: <1232039939.18652.16.camel@phoenix.blechhirn.net> In-Reply-To: <eeef1a4c0901141233l327ad964jc6fdd3a937942696@mail.gmail.com> References: <1231950392.18652.0.camel@phoenix.blechhirn.net> <eeef1a4c0901141233l327ad964jc6fdd3a937942696@mail.gmail.com>
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hi... > what is the exact function of this sysctl setting? > > I'm guessing it's something to do with Xen, having seen a few > references in Linux for xen.machdep.independent_wallclock. > > Have a look here: > http://docs.xensource.com/XenServer/4.0.1/guest/ch04s06.html yeah, I know that sysctl from linux, but I wasn't quite sure if it is the same in FreeBSD, since it's known as 'xen.independent_wallclock' in linux and 'machdep.independent_wallclock' in FreeBSD. I started reading the C-code of FreeBSD, and from my understanding the function 'should' be the same, as it's really linked to the clock handling with XEN in FreeBSD. but from my understanding it's not completly implemented in 8-CURRENT (as of 15 jan 2009; see the last lines): ================================ /* * Write system time back to RTC. */ static void domu_resettodr(void) { unsigned long tm; int s; dom0_op_t op; struct shadow_time_info *shadow; shadow = &per_cpu(shadow_time, smp_processor_id()); if (xen_disable_rtc_set) return; s = splclock(); tm = time_second; splx(s); tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); if ((xen_start_info->flags & SIF_INITDOMAIN) && !independent_wallclock) { op.cmd = DOM0_SETTIME; op.u.settime.secs = tm; op.u.settime.nsecs = 0; op.u.settime.system_time = shadow->system_timestamp; HYPERVISOR_dom0_op(&op); update_wallclock(); } else if (independent_wallclock) { /* notyet */ ; } } ================================ is that correct??? greetz olli >
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