It was added in order to limit number of goroutines performing assisted merges during ingestion.
It turned out that blocking ingestion goroutines lower ingestion performance and limits overall ingestion around 40k items per seconds because of lock contention.
Removing parts merge sync.Cond allows to remove lock contention at write path and significantly improves write performance.
See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4775
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
