Subject: softdep and memory...?
To: None <current-users@netbsd.org>
From: Mason Loring Bliss <mason@acheron.middleboro.ma.us>
List: current-users
Date: 02/29/2000 07:47:33
So, last night I finally picked up another 128 meg PC100 SIMM. I popped it
in, and my system started going berserk. I'd thought my last 128 meg PC100
SIMM was bad, so I'd borrowed two 32 meg SIMMs from work. They did the trick.
But the brand new memory I got last night seemed bad or something.

Just on a whim, I turned off softdep everywhere, and noted a complete lack
of instability. Then, feeling dangerous, I popped in my old "bad" 128 meg
SIMM and noticed a similar lack of instability. The only condition different
between the instability and the stability was the amount of RAM present in
the system.

Is it possible that softdep simply can't deal with large amounts of RAM? I
was running softdep okay with 64 megs of RAM, but having more seems to be
an irritant to softdep.

My kernel's vintage is the 16th of this month, and I remember seeing notice
of some changes. Is this memory sizing issue something that may have been
addressed in the recent softdep changes?

I'm going to change the order of my RAM anyway such that the old, "bad" SIMM
is first and hence used more, just to try to rule out the possibility that it
is in fact bad but just not being used right now, but I'm curious about
whether it would be worth building a fresh system as well, once the "flaky"
RAM has had a chance to prove itself. (This RAM survived nine hours of testing,
so I wouldn't be madly surprised to find that it's not bad.)

-- 
    Mason Loring Bliss  mason@acheron.middleboro.ma.us  I m m a n e n t i z e
awake ? sleep : dream;  http://acheron.ne.mediaone.net  t h e E s c h a t o n