> On Oct 14, 2021, at 18:09, Scott Cheloha <scottchel...@gmail.com> wrote: > > On Thu, Oct 14, 2021 at 11:37:44PM +0200, Mark Kettenis wrote: >>> Date: Thu, 14 Oct 2021 16:13:17 -0500 >>> From: Scott Cheloha <scottchel...@gmail.com> >>> >>> [...] >>> >>> Thoughts? >> >> I never understood this code. But I don't understand that if our >> timecounters are only 32 bits, we need more than 64 bits to store a >> time difference on the order of seconds... > > Let's use the TSC on my laptop as a practical example. > > […] > > If we capture the full 96-bit result we can handle a blackout of > > 37513334511718751490 / 19066590438009199874 = 2.033601938739046 > > or roughly 2 seconds on the primary CPU.
Shoot, I typo'd this. This divisor should be UINT64_MAX. The resulting quotient is still the same. Must have copied the wrong number, my bad.
