Re: [PATCH 1/6] maintenance: add get_random_minute()

On Tue, Aug 08, 2023 at 09:49:30AM -0700, Junio C Hamano wrote:

Junio C Hamano [off-list ref] writes:

quoted

Provided if code simplification is a good enough rationale, the
patch looks sensible, but I find its use of u64 a bit questionable
(though not wrong).  I would have expected that the type of "rand"
would be the same as backoff_ms and wait_ms, two variables involved
in the same expression.

Ah, not so fast.  The use of modulo means we need to be careful
about about the fuzzing factor going negative, and use of unsigned
type allows us to forget about it.

(fuzz % 250), when fuzz is of a signed random integral type, ranges
between -250 and +250 and because we want the center of our
distribution at 1000, so I think the following is equivalent.

[...]

-		wait_ms = (750 + rand % 500) * backoff_ms / 1000;
+		wait_ms = (1000 + fuzz % 250) * backoff_ms / 1000;

I was going to say that having rand be an unsigned type was the right
behavior, but with this change it can (and should) be signed. Thanks for
the simplification :-).

Thanks,
Taylor