warmReads and indexTree each spawn several zit subprocesses — ls, ls-under, a cat per file, an archive — and on a store tcl's size each takes seconds. They were launched as bare goroutines from every round that moved the tip, so the next round started another set before the last had finished and they stacked.

Measured on the demo fleet: 43 zit children under one server, three of them the same ls against the same hash, load average 546 on 14 cores.

A warm pass already running IS the warm pass. CompareAndSwap claims the slot and the winner clears it on the way out; a round that finds one in flight skips rather than piling on. check-in: 0325ba4a2c user: dmestas tags: trunk