Solutions to Saturday Mac riddles 21

I hope that you enjoyed Saturday’s Mac Riddles, episode 21. Here are my solutions to them.

1: Font Book
If you’re looking for all knowledge (the font of all knowledge), I’ll disappoint, but I have the biggest collections of characters in my pages (a book with all the characters in your fonts). What am I?

2: Jetsam
I’m not discarded goods on the beach (jetsam), nor am I a friend of the idle (Jetsam can kill idle processes), but can quietly murder to keep things running smoothly (Jetsam kills idle processes to free up their memory). What am I?

3: How much virtual memory is reserved for use by the macOS kernel? Answer: 128 TB.
The total size of virtual memory in 64-bit macOS is 256 TB, which is limited from the theoretical maximum of 16 EB. Of those 256 TB, user space is capped at 128 TB, ending at 0x7fffffffffff, which leaves 128 TB at the top (0xffffffff8…) reserved for the kernel. See Jonathan Levin’s account.

I look forward to your putting alternative cases.