Junio C Hamano [off-list ref] writes:
We used to expose the full power of the delayed progress API to the
callers, so that they can specify, not just the message to show and
expected total amount of work that is used to compute the percentage
of work performed so far, the percent-threshold parameter P and the
delay-seconds parameter N. The progress meter starts to show at N
seconds into the operation only if the amount of work completed
exceeds P.
Oops, we inspect the doneness at N seconds and show only if we have
not yet completed P percent of the total work.
Perhaps
... at N seconds into the operation only if we have not
completed P per-cent of the total work.