TAU_SET_INTERRUPT_INTERVAL(3) on Linux
The text 6db8fd458b31, as Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 4.0 (Etch) shipped it. The page shows this text now.
Change the inter-interrupt interval for tracking memory and headroom