Re: [PATCH 01/12] clocksource: Simplify clocks_calc_max_nsecs logic
From: Ingo Molnar
Date: Sat Mar 07 2015 - 04:20:32 EST
* John Stultz <john.stultz@xxxxxxxxxx> wrote:
> The previous clocks_calc_max_nsecs had some unecessarily
> complex bit logic to find the max interval that could cause
> multiplication overflows. Since this is not in the hot
> path, just do the divide to make it easier to read.
> The previous implementation also had a subtle issue
> that it avoided overflows into signed 64bit values, where
So here you write the weird '64bit' form, while in the code you write:
> + * cyc2ns function without overflowing a 64-bit result.
This repeats in later patches as well. I'd suggest using '64-bit'
consistently throughout the whole series.
> as the intervals are always unsigned. This resulted in
> overly conservative intervals, which other saftey margins
> were then added to, reducing the intended interval length.
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