following some discussions in #7814 there are a few ideas that came up and we'd like to implement:

1. async flush of the Lua VM. done in SCRIPT FLUSH run truly async, close lua interpreter in bio #13087
2. since EVAL is mostly the one that abuses the lua cache, and these won't have pipeline issues, we'd like to implement script eviction only for these (not for one loaded with SCRIPT LOAD). see memory used by Lua is allocated and freed by zrealloc()/zfree() #7814 (comment) and memory used by Lua is allocated and freed by zrealloc()/zfree() #7814 (comment) done in Lua eval scripts first in first out LRU eviction #13108
3. Allocate Lua VM code with jemalloc instead of libc, and count it used memory. for that we need to use MALLOCX_ARENA to make sure it doesn't block the defragger. see memory used by Lua is allocated and freed by zrealloc()/zfree() #7814 (comment) and SCRIPT FLUSH run truly async, close lua interpreter in bio #13087 (comment)