Messages in this thread | | | From | Pavel Tatashin <> | Date | Tue, 17 Jul 2018 21:59:15 -0400 | Subject | Re: [PATCH v13 07/18] x86/xen/time: output xen sched_clock time from 0 |
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> > +static u64 xen_sched_clock(void) > > +{ > > + return xen_clocksource_read() - xen_sched_clock_offset; > > +} > > > Should other invocations of xen_clocksource_read() also be offset? >
I do not believe so. Look in arch/x86/kernel/kvmclock.c kvm_clock_get_cycles() is not normalized for instance. We need to normalize kvm_sched_clock_read() and xen_sched_clock(), because it is used by printk() as a sched_clock() prefix. So not to be confusing we print time starting from 0, but the other instances where xen_clocksource_read() is used do not need that.
Thank you, Pavel
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