freebsd stable - Jan 2018 - i386 with 4GB RAM: less than 2GB available on A2SAV (Intel Atom E3940)

On Sun, 28-Jan-2018 at 22:51:04 +0700, Eugene Grosbein
wrote:
> 28.01.2018 21:57, Andre Albsmeier wrote:
> 
> > I have a lot of machines running with 4 GB physical RAM and, for
> > some reasons, I still have to use a 32 bits OS.
> > 
> > All of them show something between 3 and 3.5 GB of RAM available
> > in dmesg but the brand new Supermicro A2SAV really shocked me:
> > 
> > FreeBSD 11.1-STABLE #0: Mon Jan 15 06:57:10 CET 2018
> > ...
> > real memory  = 4294967296 (4096 MB)
> > avail memory = 1939558400 (1849 MB)
> > ...
> > 
> > So do people have any ideas how I might get a bit closer to at least
> > 3 GB? I assume there are no FreeBSD knobs which might help but hope
> > dies last...
> 
> First, try to decrease amount of RAM dedicated to integrated video, if any
(BIOS Setup).
Done that. I have set everything as small as possible but this didn't help.
After a BIOS upgrade, I found the promising option

MAX TOLUD

which was set to 2GB. I changed it to 3GB but nothing changed.
> 
> Also, I'd like to know reasons that made you stick to 32 bit OS
> as we have pretty good support for 32 bit applications running under 64 bit
system.
I (still) have 32 bit machines and don't want to maintain 2 userlands.
Each machine has its own kernel but userland (updated via nfs) must
remain 32 bit.

Or is it possible to boot a 64 bit kernel and have everything else in
32 bit?

On 30.01.2018 13:59, Andre Albsmeier wrote:
>> Also, I'd like to know reasons that made you stick to 32 bit OS
>> as we have pretty good support for 32 bit applications running under 64
bit system.
> 
> I (still) have 32 bit machines and don't want to maintain 2 userlands.
> Each machine has its own kernel but userland (updated via nfs) must
> remain 32 bit.
> 
> Or is it possible to boot a 64 bit kernel and have everything else in
> 32 bit?
I have not tried "everything else in 32 bit", there may be some rough
edges
dealing with run-time linker but you can try.

/sbin/init is statically linked and it should work with kernel having option
COMPAT_FREEBSD32.
/bin/sh may be OK too provided /libexec/ld-elf32.so.1 is in place.

You should really consider switching to 64 bit kernel for such hardware.

30.01.2018 09:59, Andre Albsmeier ?????:
> After a BIOS upgrade,
Did you try to reset BIOS to default settings? A BIOS upgrade
is the right time to try this.
> I found the promising option
> 
> MAX TOLUD
> 
> which was set to 2GB. I changed it to 3GB but nothing changed.
Hm, TOLUD is Top Of Lower Usable Dram. That memory is often used
for GPU (minering). I'd say that you may be interested in *decreasing*
it as it is effectively memory that is not used by an OS. There may be
an AUTO choice to try as well.

-- 
WBR, Boris Samorodov (bsam)
FreeBSD Committer, http://www.FreeBSD.org The Power To Serve