Messages in this thread | | | Date | Tue, 14 Nov 2006 09:06:09 -0800 | From | Suleiman Souhlal <> | Subject | Re: [PATCH 0/2] Make the TSC safe to be used by gettimeofday(). |
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Shem Multinymous wrote: > On 11/14/06, Suleiman Souhlal <ssouhlal@freebsd.org> wrote: > >> I believe that the results returned will always be monotonic, as long as >> the frequency of the TSC does not change from under us (that is, without >> the kernel knowing). This is because we "synchronize" each CPU's vxtime >> with a global time source (HPET) every time we know the TSC rate changes. > > > Does this hold after a suspend/resume cycle? You could be resuming > with a different CPU clock than what you suspended with, and I'm not > sure anything guarantees an early enough re-sync.
I have to admit that I didn't really design this patch with suspend/resume in mind, and that I'm not too familiar with how they work.
Do the HPET/ACPI timers still run while the system is suspended? If not, there shouldn't be any problem, as long as the kernel is informed of the resume early enough.
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