Re: Deadlock on fragmented memory?

[Taylor R Campbell <campbell+netbsd-tech-kern%mumble.net@localhost>]

> Date: Mon, 23 Oct 2017 20:15:24 +0200
> From: Jaromír Doleček <jaromir.dolecek%gmail.com@localhost>
> 
> How difficult you gather it would be to convert the execargs to use 4K
> pages rathern then continuous KVA, are there any particular gotchas? I
> would be interested to look at this - it sounds like nice high-kernel only
> project for me, to make a break from the ATA oddities.

Mostly I expect it to be a lot of bookkeeping.  If I were doing it,
I'd probably use struct uio or similar so that I can easily uiomove to
incrementally set it up, and draw a page at a time from kmem_alloc or
from a dedicated pool cache as necessary to expand it.

(I expect using just a pool for pages at a time, rather than 256 KB at
a time as we do now, would incur a lot of contention for long argument
lists, like in builds.)