[tor-relays] "Removed 1565259696 bytes by killing 1 circuits"

In a relay's logs: Oct 20 10:31:47 XXXXX Tor[YYYY]: We're low on memory. Killing circuits with over-long queues. (This behavior is controlled by MaxMemInQueues.) Oct 20 10:32:11 XXXXX Tor[YYYY]: Removed 1565259696 bytes by killing 1 circuits; 40008 circuits remain alive. Also killed 0 non-linked directory connections. Tor removed ~ 1565 MB by killing 1 circuit? Seems like that can't be right? Earlier in the log I see "Based on detected system memory, MaxMemInQueues is set to 1500 MB." So either it's dumping the entire queue here, or the output is misleading. Or perhaps I don't understand how it works. It doesn't seem to be impactful; I'm just curious what's going on.