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Author here. Completely agreed. My jaws dropped when I saw the INITIAL_JIFFIES. The kernel developers really saved our butt.

I could not imagine debugging this problem if INITIAL_JIFFIES was randomized. It may takes days/weeks/months for this bug to appear.

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Similarly, Unreal Engine 4 offsets platform time (a double) by some large value so if it's stored in a float, accuracy errors will be exposed almost immediately. Looking it up, the offset starts out large enough that the epsilon is two seconds.

Do you have a link with more info? I'd love to read more about this.

Sorry, no. It's not something documented other than a cryptic comment in the source code ( FPlatformTime::Seconds() ) assuming some knowledge of floating point number gotchas.

Edit: Here's a more detailed post o made about the specific gotcha if you're interested: https://community.gamedev.tv/t/why-is-fplatformtime-seconds-...

Here's the patch that applies this: https://www.kernel.org/pub/linux/kernel/people/akpm/patches/...

Nice! I was looking for it, and it predates git. Thank you!!

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