gitserver: kill the zombies of CommitSearcher
Created by: tsenart
This is a Halloween commit that kills the zombies left by CommitSearcher.feedBatches
.
This is one of the possible causes of latency degradation of gitserver commands in gitserver-13
and gitserver-7
.
Incident: https://sourcegraph.slack.com/archives/C02K9EPTBQX/p1635764046017800