recent head having significantly less "avail memory"

From: Guido Falsi via freebsd-current <freebsd-current_at_freebsd.org>
Date: Mon, 13 Sep 2021 12:59:25 UTC
Hi,

I updated head recently and today I noticed a difference which looks wrong.

At boodt the new head shows signifcantly less avail memory than before, 
around 3 GiB less.

I moved from commit 71fbc6faed6 [1] where I got:

Aug 28 22:03:03 marvin kernel: real memory  = 17179869184 (16384 MB)
Aug 28 22:03:03 marvin kernel: avail memory = 16590352384 (15821 MB)

to commit 7955efd574b [2] where I get:

Sep 13 10:44:40 marvin kernel: real memory  = 17179869184 (16384 MB)
Sep 13 10:44:40 marvin kernel: avail memory = 13298876416 (12682 MB)

I'm seeing this on multiple machines.

Unluckily bisecting and trying an older loader.efi in sseparate tests 
did not give me any more insight.

The recent changes to efi loader, starting with commit 6032b6ba9596 [3] 
look like a possible trigger to this, but I have been unable to confirm it.

Any suggesstions on how to proceed to debug thiss? ANy idea what a fix 
could be?


[1] 
https://cgit.freebsd.org/src/commit/?id=71fbc6faed62e8eb5864f7c40839740f5e9f5558

[2] 
https://cgit.freebsd.org/src/commit/?id=7955efd574b98601a95da45d6d8e7f452631fddd

[3] 
https://cgit.freebsd.org/src/commit/?id=6032b6ba9596927aba15a8004ade521a593a7d58

-- 
Guido Falsi <mad@madpilot.net>