Wiktionary
n. 1 (context programming English) In assembly languages, a loop which contains few machine instructions and iterates many times. 2 (context programming English) Such a loop which heavily uses I/O or central processing unit resources, failing to adequately share them with other programs running in the operating system.
Wikipedia
Usage examples of "tight loop".
The best he could manage was to sling the strip over his back, bring it around under his armpit and tie it in a tight loop over his shoulder.
His tactics here were purely evasive, ducking and then rising suddenly in a tight loop, then plunging down the back side of that loop into the fog.
Time to come around in a tight loop and hit the rear guard if the TIEs had one, fall upon the TIEs from the rear if they didn't.
Corran flew straight through the explosion, and then pulled his X-wing up into a tight loop.
He led Mara and Corran in a tight loop back toward the engagement zone.
About the necks of most, knotted still, was a tight loop of binding fiber, though it had been cut on both sides, to free them from the coffle.
Xanthon trapped one dragoneer's iron sword in the head of a halberd and began a tight loop, preparing to fling the weapon out of the warrior's grasp.
I inverted and dove, then throttled back and came up through a tight loop that should have dropped me on his tail.
Her target is pulling through a tight loop and she's following, while the two garrals try to cut across the circle and nail Rhysati.