Messages in this thread | | | Date | Mon, 22 Mar 2010 15:22:12 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [RFC][PATCH] Convert alpha to use clocksource |
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On Mon, 22 Mar 2010, Johannes Weiner wrote: > > Though, even after a glance over the clocksource code, I've not > > gotten yet to how one could estimate the "shift" value... > > Any hints? > > I had the same problem with xtensa and added a comment about what I > did in there, maybe it helps: > > arch/xtensa/kernel/time.c > > I took the upper bound of the multiplicator (nsecs per counter unit) > and subtracted its logarithm from my available 32 bits. The result > is the highest possible shift value that works for the clocksource.
clocks_calc_mult_shift() is what you are looking for.
Thanks,
tglx
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