Please build busybox swapon with discard support
Username: rsalvaterra
Origin: https://bugs.openwrt.org/index.php?do=details&task_id=1648
Busybox supports swap discard mounting since late March 2014[1]. Zram suports TRIM/discard since early April 2014[2]. On OpenWrt systems with zram-swap, being able to mount the zram swap space as discardable would be quite beneficial, since compressed freed pages would be immediately returned to the system.
[1]
https://git.busybox.net/busybox/commit/?id=0a53b203f9e7157136c8ab4e8753008a63a56660
[2]